Publications by year
In Press
Chaloner TM, Gurr SJ, Bebber DP (In Press). Geometry and evolution of the ecological niche in plant-associated microbes.
Abstract:
Geometry and evolution of the ecological niche in plant-associated microbes
AbstractThe ecological niche of a species can be conceptualized as a volume in multidimensional space, where each dimension describes an abiotic condition or biotic resource. The shape and size of this volume strongly determines interactions among species and influences their global distribution, but the geometry of the niche is poorly understood. Here, we analyse temperature response functions and host plant ranges for hundreds of fungi and oomycetes. We demonstrate that niche specialization is independent on abiotic and biotic axes, that host interactions restrict fundamental niche breadth to form the realized niche, and that both abiotic and biotic niches show limited phylogenetic constraint. Such niche adaptability makes plant pathogens a formidable threat to agriculture and forestry.
Abstract.
Gurr SJ, McPherson MJ, Atkinson HJ (In Press). Identification of plant genes expressed at the feeding site of the potato cyst nematode. Journal Cell Biochemistry, 56, 121-131.
Chaloner TM, Gurr SJ, Bebber DP (In Press). Plant pathogen infection risk tracks global crop yields under climate change.
Abstract:
Plant pathogen infection risk tracks global crop yields under climate change
AbstractGlobal food security is strongly determined by crop production. Climate change-induced losses to production can occur directly, or indirectly, including via the distributions and impacts of plant pathogens. However, the likely changes in pathogen pressure in relation to global crop production are poorly understood. Here we show that temperature-dependent infection risk, r(T), for 80 fungal and oomycete crop pathogens will track projected yield changes in 12 crops over the 21st Century. For most crops, both yields and r(T) are likely to increase at high latitudes. In contrast, while the tropics will see little or no productivity gains, r(T) is also likely to decline. In addition, the USA, Europe and China may experience major changes in pathogen assemblages. The benefits of yield gains may therefore be tempered by the increased burden of crop protection due to increased and unfamiliar pathogens.
Abstract.
Gurr SJ, Field D, Garrity G, Selengut J, Sterk P, Tatusova T, Thomson N, Ashburner M, Boore JL, Cochrane G, et al (In Press). Towards richer descriptions of our collection of genomes and metagenomes. Nature Biotechnology, 16, LBNL-60477.
2022
Johns LE, Bebber DP, Gurr SJ, Brown NA (2022). Emerging health threat and cost of Fusarium mycotoxins in European wheat.
Nature Food,
3(12), 1014-1019.
Abstract:
Emerging health threat and cost of Fusarium mycotoxins in European wheat
AbstractMycotoxins harm human and livestock health, while damaging economies. Here we reveal the changing threat of Fusarium head blight (FHB) mycotoxins in European wheat, using data from the European Food Safety Agency and agribusiness (BIOMIN, World Mycotoxin Survey) for ten years (2010–2019). We show persistent, high, single- and multi-mycotoxin contamination alongside changing temporal-geographical distributions, indicative of altering FHB disease pressure and pathogen populations, highlighting the potential synergistic negative health consequences and economic cost.
Abstract.
Cannon S, Kay W, Kilaru S, Schuster M, Gurr SJ, Steinberg G (2022). Multi-site fungicides suppress banana Panama disease, caused by Fusarium oxysporum f. sp. cubense Tropical Race 4.
PLOS Pathogens,
18(10), e1010860-e1010860.
Abstract:
Multi-site fungicides suppress banana Panama disease, caused by Fusarium oxysporum f. sp. cubense Tropical Race 4
Global banana production is currently challenged by Panama disease, caused by Fusarium oxysporum f.sp. cubense Tropical Race 4 (FocTR4). There are no effective fungicide-based strategies to control this soil-borne pathogen. This could be due to insensitivity of the pathogen to fungicides and/or soil application per se. Here, we test the effect of 12 single-site and 9 multi-site fungicides against FocTR4 and Foc Race1 (FocR1) in quantitative colony growth, and cell survival assays in purified FocTR4 macroconidia, microconidia and chlamydospores. We demonstrate that these FocTR4 morphotypes all cause Panama disease in bananas. These experiments reveal innate resistance of FocTR4 to all single-site fungicides, with neither azoles, nor succinate dehydrogenase inhibitors (SDHIs), strobilurins or benzimidazoles killing these spore forms. We show in fungicide-treated hyphae that this innate resistance occurs in a subpopulation of "persister" cells and is not genetically inherited. FocTR4 persisters respond to 3 μg ml-1 azoles or 1000 μg ml-1 strobilurins or SDHIs by strong up-regulation of genes encoding target enzymes (up to 660-fold), genes for putative efflux pumps and transporters (up to 230-fold) and xenobiotic detoxification enzymes (up to 200-fold). Comparison of gene expression in FocTR4 and Zymoseptoria tritici, grown under identical conditions, reveals that this response is only observed in FocTR4. In contrast, FocTR4 shows little innate resistance to most multi-site fungicides. However, quantitative virulence assays, in soil-grown bananas, reveals that only captan (20 μg ml-1) and all lipophilic cations (200 μg ml-1) suppress Panama disease effectively. These fungicides could help protect bananas from future yield losses by FocTR4.
Abstract.
Fisher MC, Alastruey-Izquierdo A, Berman J, Bicanic T, Bignell EM, Bowyer P, Bromley M, Brüggemann R, Garber G, Cornely OA, et al (2022). Tackling the emerging threat of antifungal resistance to human health.
Nat Rev Microbiol,
20(9), 557-571.
Abstract:
Tackling the emerging threat of antifungal resistance to human health.
Invasive fungal infections pose an important threat to public health and are an under-recognized component of antimicrobial resistance, an emerging crisis worldwide. Across a period of profound global environmental change and expanding at-risk populations, human-infecting pathogenic fungi are evolving resistance to all licensed systemic antifungal drugs. In this Review, we highlight the main mechanisms of antifungal resistance and explore the similarities and differences between bacterial and fungal resistance to antimicrobial control. We discuss the research and innovation topics that are needed for risk reduction strategies aimed at minimizing the emergence of resistance in pathogenic fungi. These topics include links between the environment and One Health, surveillance, diagnostics, routes of transmission, novel therapeutics and methods to mitigate hotspots for fungal adaptation. We emphasize the global efforts required to steward our existing antifungal armamentarium, and to direct the research and development of future therapies and interventions.
Abstract.
Author URL.
Case NT, Berman J, Blehert DS, Cramer RA, Cuomo C, Currie CR, Ene IV, Fisher MC, Fritz-Laylin LK, Gerstein AC, et al (2022). The future of fungi: threats and opportunities.
G3 (Bethesda),
12(11).
Abstract:
The future of fungi: threats and opportunities.
The fungal kingdom represents an extraordinary diversity of organisms with profound impacts across animal, plant, and ecosystem health. Fungi simultaneously support life, by forming beneficial symbioses with plants and producing life-saving medicines, and bring death, by causing devastating diseases in humans, plants, and animals. With climate change, increased antimicrobial resistance, global trade, environmental degradation, and novel viruses altering the impact of fungi on health and disease, developing new approaches is now more crucial than ever to combat the threats posed by fungi and to harness their extraordinary potential for applications in human health, food supply, and environmental remediation. To address this aim, the Canadian Institute for Advanced Research (CIFAR) and the Burroughs Wellcome Fund convened a workshop to unite leading experts on fungal biology from academia and industry to strategize innovative solutions to global challenges and fungal threats. This report provides recommendations to accelerate fungal research and highlights the major research advances and ideas discussed at the meeting pertaining to 5 major topics: (1) Connections between fungi and climate change and ways to avert climate catastrophe; (2) Fungal threats to humans and ways to mitigate them; (3) Fungal threats to agriculture and food security and approaches to ensure a robust global food supply; (4) Fungal threats to animals and approaches to avoid species collapse and extinction; and (5) Opportunities presented by the fungal kingdom, including novel medicines and enzymes.
Abstract.
Author URL.
Kilaru S, Fantozzi E, Cannon S, Schuster M, Chaloner TM, Guiu-Aragones C, Gurr SJ, Steinberg G (2022). Zymoseptoria tritici white-collar complex integrates light, temperature and plant cues to initiate dimorphism and pathogenesis.
Nature Communications,
13(1).
Abstract:
Zymoseptoria tritici white-collar complex integrates light, temperature and plant cues to initiate dimorphism and pathogenesis
AbstractTransitioning from spores to hyphae is pivotal to host invasion by the plant pathogenic fungus Zymoseptoria tritici. This dimorphic switch can be initiated by high temperature in vitro (~27 °C); however, such a condition may induce cellular heat stress, questioning its relevance to field infections. Here, we study the regulation of the dimorphic switch by temperature and other factors. Climate data from wheat-growing areas indicate that the pathogen sporadically experiences high temperatures such as 27 °C during summer months. However, using a fluorescent dimorphic switch reporter (FDR1) in four wild-type strains, we show that dimorphic switching already initiates at 15–18 °C, and is enhanced by wheat leaf surface compounds. Transcriptomics reveals 1261 genes that are up- or down-regulated in hyphae of all strains. These pan-strain core dimorphism genes (PCDGs) encode known effectors, dimorphism and transcription factors, and light-responsive proteins (velvet factors, opsins, putative blue light receptors). An FDR1-based genetic screen reveals a crucial role for the white-collar complex (WCC) in dimorphism and virulence, mediated by control of PCDG expression. Thus, WCC integrates light with biotic and abiotic cues to orchestrate Z. tritici infection.
Abstract.
2021
Fantozzi E, Kilaru S, Gurr SJ, Steinberg G (2021). Asynchronous development of Zymoseptoria tritici infection in wheat.
Fungal Genet Biol,
146Abstract:
Asynchronous development of Zymoseptoria tritici infection in wheat.
The fungus Zymoseptoria tritici causes Septoria tritici blotch of wheat. Pathogenicity begins with spore germination, followed by stomata invasion by hyphae, mesophyll colonization and fruiting body formation. It was previously found that entry into the plant via stomata occurs in a non-synchronized way over several days, while later developmental steps, such as early and late fruiting body formation, were reported to follow each other in time. This suggests synchronization of the pathogen population in planta prior to sporulation. Here, we image a fluorescent Z. tritici IPO323-derived strain during infection. We describe 6 morphologically distinct developmental stages, and determine their abundance in infected leaves, with time post inoculation. This demonstrates that 3-5 stages co-exist in infected tissues at any given time. Thus, later stages of pathogen development also occur asynchronously amongst the population of infecting cells. This merits consideration when interpreting transcriptomics or proteomics data gathered from infected plants.
Abstract.
Author URL.
Fantozzi E, Kilaru S, Cannon S, Schuster M, Gurr SJ, Steinberg G (2021). Conditional promoters to investigate gene function during wheat infection by Zymoseptoria tritici.
Fungal Genet Biol,
146Abstract:
Conditional promoters to investigate gene function during wheat infection by Zymoseptoria tritici.
The fungus Zymoseptoria tritici causes Septoria tritici leaf blotch, which poses a serious threat to temperate-grown wheat. Recently, we described a raft of molecular tools to study the biology of this fungus in vitro. Amongst these are 5 conditional promoters (Pnar1, Pex1A, Picl1, Pgal7, PlaraB), which allow controlled over-expression or repression of target genes in cells grown in liquid culture. However, their use in the host-pathogen interaction in planta was not tested. Here, we investigate the behaviour of these promoters by quantitative live cell imaging of green-fluorescent protein-expressing cells during 6 stages of the plant infection process. We show that Pnar1 and Picl1 are repressed in planta and demonstrate their suitability for studying essential gene expression and function in plant colonisation. The promoters Pgal7 and Pex1A are not fully-repressed in planta, but are induced during pycnidiation. This indicates the presence of inducing galactose or xylose and/or arabinose, released from the plant cell wall by the activity of fungal hydrolases. In contrast, the PlaraB promoter, which normally controls expression of an α-l-arabinofuranosidase B, is strongly induced inside the leaf. This suggests that the fungus is exposed to L-arabinose in the mesophyll apoplast. Taken together, this study establishes 2 repressible promoters (Pnar1 and Picl1) and three inducible promoters (Pgal7, Pex1A, PlaraB) for molecular studies in planta. Moreover, we provide circumstantial evidence for plant cell wall degradation during the biotrophic phase of Z. tritici infection.
Abstract.
Author URL.
Chaloner TM, Gurr SJ, Bebber DP (2021). Plant pathogen infection risk tracks global crop yields under climate change.
NATURE CLIMATE CHANGE,
11(8), 710-+.
Author URL.
2020
Steinberg G, Schuster M, Gurr SJ, Schrader TA, Schrader M, Wood M, Early A, Kilaru S (2020). A lipophilic cation protects crops against fungal pathogens by multiple modes of action.
Nat Commun,
11(1).
Abstract:
A lipophilic cation protects crops against fungal pathogens by multiple modes of action.
The emerging resistance of crop pathogens to fungicides poses a challenge to food security and compels discovery of new antifungal compounds. Here, we show that mono-alkyl lipophilic cations (MALCs) inhibit oxidative phosphorylation by affecting NADH oxidation in the plant pathogens Zymoseptoria tritici, Ustilago maydis and Magnaporthe oryzae. One of these MALCs, consisting of a dimethylsulfonium moiety and a long alkyl chain (C18-SMe2+), also induces production of reactive oxygen species at the level of respiratory complex I, thus triggering fungal apoptosis. In addition, C18-SMe2+ activates innate plant defense. This multiple activity effectively protects cereals against Septoria tritici blotch and rice blast disease. C18-SMe2+ has low toxicity in Daphnia magna, and is not mutagenic or phytotoxic. Thus, MALCs hold potential as effective and non-toxic crop fungicides.
Abstract.
Author URL.
Fones HN, Bebber DP, Chaloner TM, Kay WT, Steinberg G, Gurr SJ (2020). Author Correction: Threats to global food security from emerging fungal and oomycete crop pathogens. Nature Food, 1(7), 455-456.
Steinberg G, Gurr SJ (2020). Fungi, fungicide discovery and global food security.
Fungal Genet Biol,
144Abstract:
Fungi, fungicide discovery and global food security.
Securing sufficient food for a growing world population is of paramount importance for social stability and the well-being of mankind. Recently, it has become evident that fungal pathogens pose the greatest biotic challenge to our calorie crops. Moreover, the loss of commodity crops to fungal disease destabilises the economies of developing nations, thereby increasing the dimension of the threat. Our best weapon to control these pathogens is fungicides, but increasing resistance puts us in an arms race against them. New anti-fungal compounds need to be discovered, such as mono-alky lipophilic cations (MALCs) described herein. Collaborations between academia and industry are imperative to establish new and efficient ways to develop these new fungicides and to bring them to the market-place.
Abstract.
Author URL.
Chaloner TM, Gurr SJ, Bebber DP (2020). Geometry and evolution of the ecological niche in plant-associated microbes.
Nature communications,
11(1).
Abstract:
Geometry and evolution of the ecological niche in plant-associated microbes.
The ecological niche can be thought of as a volume in multidimensional space, where each dimension describes an abiotic condition or biotic resource required by a species. The shape, size, and evolution of this volume strongly determine interactions among species and influence their current and potential geographical distributions, but the geometry of niches is poorly understood. Here, we analyse temperature response functions and host plant ranges for hundreds of potentially destructive plant-associated fungi and oomycetes. We demonstrate that niche specialization is uncorrelated on abiotic (i.e. temperature response) and biotic (i.e. host range) axes, that host interactions restrict fundamental niche breadth to form the realized niche, and that both abiotic and biotic niches show limited phylogenetic constraint. The ecological terms 'generalist' and 'specialist' therefore do not apply to these microbes, as specialization evolves independently on different niche axes. This adaptability makes plant pathogens a formidable threat to agriculture and forestry.
Abstract.
Fisher MC, Gurr SJ, Cuomo CA, Blehert DS, Jin H, Stukenbrock EH, Stajich JE, Kahmann R, Boone C, Denning DW, et al (2020). Threats Posed by the Fungal Kingdom to Humans, Wildlife, and Agriculture.
mBio,
11(3).
Abstract:
Threats Posed by the Fungal Kingdom to Humans, Wildlife, and Agriculture.
The fungal kingdom includes at least 6 million eukaryotic species and is remarkable with respect to its profound impact on global health, biodiversity, ecology, agriculture, manufacturing, and biomedical research. Approximately 625 fungal species have been reported to infect vertebrates, 200 of which can be human associated, either as commensals and members of our microbiome or as pathogens that cause infectious diseases. These organisms pose a growing threat to human health with the global increase in the incidence of invasive fungal infections, prevalence of fungal allergy, and the evolution of fungal pathogens resistant to some or all current classes of antifungals. More broadly, there has been an unprecedented and worldwide emergence of fungal pathogens affecting animal and plant biodiversity. Approximately 8,000 species of fungi and Oomycetes are associated with plant disease. Indeed, across agriculture, such fungal diseases of plants include new devastating epidemics of trees and jeopardize food security worldwide by causing epidemics in staple and commodity crops that feed billions. Further, ingestion of mycotoxins contributes to ill health and causes cancer. Coordinated international research efforts, enhanced technology translation, and greater policy outreach by scientists are needed to more fully understand the biology and drivers that underlie the emergence of fungal diseases and to mitigate against their impacts. Here, we focus on poignant examples of emerging fungal threats in each of three areas: human health, wildlife biodiversity, and food security.
Abstract.
Author URL.
Fones HN, Bebber DP, Chaloner TM, Kay WT, Steinberg G, Gurr SJ (2020). Threats to global food security from emerging fungal and oomycete crop pathogens. Nature Food, 1(6), 332-342.
2019
Chaloner TM, Fones HN, Varma V, Bebber DP, Gurr SJ (2019). A new mechanistic model of weather-dependent Septoria tritici blotch disease risk.
Philos Trans R Soc Lond B Biol Sci,
374(1775).
Abstract:
A new mechanistic model of weather-dependent Septoria tritici blotch disease risk.
We present a new mechanistic model for predicting Septoria tritici blotch (STB) disease, parameterized with experimentally derived data for temperature- and wetness-dependent germination, growth and death of the causal agent, Zymoseptoria tritici. The output of this model (A) was compared with observed disease data for UK wheat over the period 2002-2016. In addition, we compared the output of a second model (B), in which experimentally derived parameters were replaced by a modified version of a published Z. tritici thermal performance equation, with the same observed disease data. Neither model predicted observed annual disease, but model a was able to differentiate UK regions with differing average disease risks over the entire period. The greatest limitations of both models are: broad spatial resolution of the climate data, and lack of host parameters. Model B is further limited by its lack of explicitly defined pathogen death, leading to a cumulative overestimation of disease over the course of the growing season. Comparison of models a and B demonstrates the importance of accounting for the temperature-dependency of pathogen processes important in the initiation and progression of disease. However, effective modelling of STB will probably require similar experimentally derived parameters for host and environmental factors, completing the disease triangle. This article is part of the theme issue 'Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes'. This issue is linked with the subsequent theme issue 'Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control'.
Abstract.
Author URL.
Bebber D, Gurr S (2019). Biotic interactions and climate in species distribution modelling.
Abstract:
Biotic interactions and climate in species distribution modelling
Summary Species have preferred environmental niches 1 and their geographical distributions respond to global climate change 2. Predicting range shifts under climate change has profound implications for conservation of biodiversity 3 , provision of ecosystem services, and in the management of invasive species 4. Species distribution modelling (SDM) has largely focussed on climate variations, but biotic interactions, such as predation and competition, can alter potential distributions 5,6 and affect migration rates 7. However, a lack of data on biotic interactions has restricted consideration of these factors for many species 1. Here, we compare the power of biotic and climatic factors as predictors of global distributions of hundreds of crop pests and pathogens (CPPs), for which host preferences are known. We show that host availability is a more important predictor of endobiotic pathogen distributions (fungi, oomycetes, bacteria, viruses and nematodes) than of epibiotic pest distributions (insect herbivores). Conversely, climatic variables are better predictors of epibiotic pest distributions. These results are robust to statistical controls for varying observational capacity among countries. Our findings demonstrate that life history affects global scale species distributions and that SDM should incorporate biotic interactions as well as climate.
Abstract.
Bebber DP, Field E, Heng G, Mortimer P, Holmes T, Gurr SJ (2019). Many unreported crop pests and pathogens are probably already present.
Bebber DP, Field E, Gui H, Mortimer P, Holmes T, Gurr SJ (2019). Many unreported crop pests and pathogens are probably already present.
Glob Chang Biol,
25(8), 2703-2713.
Abstract:
Many unreported crop pests and pathogens are probably already present.
Invasive species threaten global biodiversity, food security and ecosystem function. Such incursions present challenges to agriculture where invasive species cause significant crop damage and require major economic investment to control production losses. Pest risk analysis (PRA) is key to prioritize agricultural biosecurity efforts, but is hampered by incomplete knowledge of current crop pest and pathogen distributions. Here, we develop predictive models of current pest distributions and test these models using new observations at subnational resolution. We apply generalized linear models (GLM) to estimate presence probabilities for 1,739 crop pests in the CABI pest distribution database. We test model predictions for 100 unobserved pest occurrences in the People's Republic of China (PRC), against observations of these pests abstracted from the Chinese literature. This resource has hitherto been omitted from databases on global pest distributions. Finally, we predict occurrences of all unobserved pests globally. Presence probability increases with host presence, presence in neighbouring regions, per capita GDP and global prevalence. Presence probability decreases with mean distance from coast and known host number per pest. The models are good predictors of pest presence in provinces of the PRC, with area under the ROC curve (AUC) values of 0.75-0.76. Large numbers of currently unobserved, but probably present pests (defined here as unreported pests with a predicted presence probability >0.75), are predicted in China, India, southern Brazil and some countries of the former USSR. We show that GLMs can predict presences of pseudoabsent pests at subnational resolution. The Chinese literature has been largely inaccessible to Western academia but contains important information that can support PRA. Prior studies have often assumed that unreported pests in a global distribution database represent a true absence. Our analysis provides a method for quantifying pseudoabsences to enable improved PRA and species distribution modelling.
Abstract.
Author URL.
Kay WT, Fones HN, Gurr SJ (2019). Rapid loss of virulence during submergence of Z. tritici asexual spores.
Fungal Genet Biol,
128, 14-19.
Abstract:
Rapid loss of virulence during submergence of Z. tritici asexual spores.
Zymoseptoria tritici, the causal agent of Septoria tritici blotch, is a notable pathogen of temperate-grown wheat. To better understand the mechanisms underpinning pathogenicity, leaf infection assays are commonly used to compare either the virulence of Z. tritici wildtype or mutant strains, or the susceptibility of wheat cultivars. These assays, which control for many biotic, abiotic and experimental variables, involve the application of known spore numbers to leaves. To achieve this, spore numbers are quantified during a period of aqueous suspension. Published methods rarely state the period in which spores are held in suspension, suggesting that this variable may be uncontrolled. Using simple, agar-based plating experiments, this work firstly demonstrates that blastospore culturability (the ability to form a colony when plated on appropriate agar) decreases rapidly over time during maintenance in aqueous suspension. It is subsequently shown that this reduction in culturability correlates to a reduction in the virulence of the blastospore population. This is shown in three wild type Z. tritici strains. From this, it is concluded that suspension time is a variable of major importance in experimental design and one which, if not controlled, may lead to erroneous conclusions from inter-strain comparisons. The conidia of the unrelated fungus Magnaporthe oryzae also rapidly lose culturability when stored in aqueous suspension, whereas the microspores of Fusarium oxysporum f. sp. cubense do not, suggesting that this phenomenon occurs in some but not all other fungi. Finally, a droplet method of inoculations is proposed to decrease the variability in the numbers of spores applied, within and between experiments.
Abstract.
Author URL.
2018
Carver TLW, Gurr SJ (2018). Filamentous Fungi on Plant Surfaces. In (Ed) Annual Plant Reviews online, 368-397.
Fisher MC, Hawkins NJ, Sanglard D, Gurr SJ (2018). Worldwide emergence of resistance to antifungal drugs challenges human health and food security.
Science,
360(6390), 739-742.
Abstract:
Worldwide emergence of resistance to antifungal drugs challenges human health and food security
The recent rate of emergence of pathogenic fungi that are resistant to the limited number of commonly used antifungal agents is unprecedented. The azoles, for example, are used not only for human and animal health care and crop protection but also in antifouling coatings and timber preservation. The ubiquity and multiple uses of azoles have hastened the independent evolution of resistance in many environments. One consequence is an increasing risk in human health care from naturally occurring opportunistic fungal pathogens that have acquired resistance to this broad class of chemicals. To avoid a global collapse in our ability to control fungal infections and to avoid critical failures in medicine and food security, we must improve our stewardship of extant chemicals, promote new antifungal discovery, and leverage emerging technologies for alternative solutions.
Abstract.
2017
Fones HN, Eyles CJ, Kay W, Cowper J, Gurr SJ (2017). A role for random, humidity-dependent epiphytic growth prior to invasion of wheat by Zymoseptoria tritici. Fungal Genetics and Biology, 106, 51-60.
Fones HN, Fisher MC, Gurr SJ (2017). Emerging Fungal Threats to Plants and Animals Challenge Agriculture and Ecosystem Resilience.
Microbiology spectrum,
5(2).
Abstract:
Emerging Fungal Threats to Plants and Animals Challenge Agriculture and Ecosystem Resilience
While fungi can make positive contributions to ecosystems and agro-ecosystems, for example, in mycorrhizal associations, they can also have devastating impacts as pathogens of plants and animals. In undisturbed ecosystems, most such negative interactions will be limited through the coevolution of fungi with their hosts. In this article, we explore what happens when pathogenic fungi spread beyond their natural ecological range and become invasive on naïve hosts in new ecosystems. We will see that such invasive pathogens have been problematic to humans and their domesticated plant and animal species throughout history, and we will discuss some of the most pressing fungal threats of today.
Abstract.
Fones HN, Fisher MC, Gurr SJ (2017). Emerging fungal threats to plants and animals challenge agriculture and ecosystem resilience. In (Ed)
The Fungal Kingdom, 787-809.
Abstract:
Emerging fungal threats to plants and animals challenge agriculture and ecosystem resilience
Abstract.
Geoghegan IA, Gurr SJ (2017). Investigating chitin deacetylation and chitosan hydrolysis during vegetative growth in <i>Magnaporthe oryzae</i>. Cellular Microbiology, 19(9), e12743-e12743.
Fones HN, Gurr SJ (2017). NoXious gases and the unpredictability of emerging plant pathogens under climate change.
BMC Biology,
15Abstract:
NoXious gases and the unpredictability of emerging plant pathogens under climate change
Emerging pathogens of crops threaten food security and are increasingly problematic due to intensive agriculture and high volumes of trade and transport in plants and plant products. The ability to predict pathogen risk to agricultural regions would therefore be valuable. However, predictions are complicated by multi-faceted relationships between crops, their pathogens, and climate change. Climate change is related to industrialization, which has brought not only a rise in greenhouse gas emissions but also an increase in other atmospheric pollutants. Here, we consider the implications of rising levels of reactive nitrogen gases and their manifold interactions with crops and crop diseases.
Abstract.
Geoghegan I, steinberg, gurr (2017). The Role of the Fungal Cell Wall in the Infection of Plants. Trends in Microbiology
2016
Gurr SJ, Fones HN, Mardon C (2016). A role for the asexual spores in infection of Fraxinus excelsior by the ash-dieback fungus Hymenoscyphus fraxineus.
Scientific Reports,
6Abstract:
A role for the asexual spores in infection of Fraxinus excelsior by the ash-dieback fungus Hymenoscyphus fraxineus
The invasive pathogen, ash dieback fungus Hymenoscyphus fraxineus, is spreading rapidly across Europe. It shows high levels of outcrossing and limited population structure, even at the epidemic front. The anamorphic (asexual) form produces prolific conidia, thought to function solely as spermatia (male gametes), facilitating gene flow between sympatric strains. Here, we show that conidia are capable of germination on ash leaves and in vitro, and can infect seedlings via leaves or soil. In leaves, germlings form structures resembling fruiting bodies. Additionally, H. fraxineus colonises ash debris and grows in soil in the absence of ash tissues. We propose an amended life-cycle in which wind-dispersed, insect-vectored or water-spread conidia infect ash and may sporulate in planta, as well as in forest debris. This amplifies inoculum levels of different strains in ash stands. In combination with their function as spermatia, conidia thus act to maximise gene flow between sympatric strains, including those originally present at low inoculum. Such mixing increases evolutionary potential, as well as enhancing the likelihood of gene introgression from closely-related strains or assimilation of further genetic diversity from parental Asian populations. This scenario increases the adaptability of H. fraxineus to new climates and, indeed, onto new host species.
Abstract.
Lin C, Schuster M, Guimaraes SC, Ashwin P, Schrader M, Metz J, Hacker C, Gurr SJ, Steinberg G (2016). Active diffusion and microtubule-based transport oppose myosin forces to position organelles in cells.
Nat Commun,
7Abstract:
Active diffusion and microtubule-based transport oppose myosin forces to position organelles in cells.
Even distribution of peroxisomes (POs) and lipid droplets (LDs) is critical to their role in lipid and reactive oxygen species homeostasis. How even distribution is achieved remains elusive, but diffusive motion and directed motility may play a role. Here we show that in the fungus Ustilago maydis ∼95% of POs and LDs undergo diffusive motions. These movements require ATP and involve bidirectional early endosome motility, indicating that microtubule-associated membrane trafficking enhances diffusion of organelles. When early endosome transport is abolished, POs and LDs drift slowly towards the growing cell end. This pole-ward drift is facilitated by anterograde delivery of secretory cargo to the cell tip by myosin-5. Modelling reveals that microtubule-based directed transport and active diffusion support distribution, mobility and mixing of POs. In mammalian COS-7 cells, microtubules and F-actin also counteract each other to distribute POs. This highlights the importance of opposing cytoskeletal forces in organelle positioning in eukaryotes.
Abstract.
Author URL.
Geoghegan IA, Gurr SJ (2016). Chitosan Mediates Germling Adhesion in Magnaporthe oryzae and is Required for Surface Sensing and Germling Morphogenesis. PLOS Pathogens, 12(6), e1005703-e1005703.
Schuster M, Martin-Urdiroz M, Higuchi Y, Hacker C, Kilaru S, Gurr SJ, Steinberg G (2016). Co-Delivery of Cell-Wall-Forming enzymes in the same vesicle for coordinated fungal cell wall formation.
Nature Microbiology,
1Abstract:
Co-Delivery of Cell-Wall-Forming enzymes in the same vesicle for coordinated fungal cell wall formation
Fungal cells are surrounded by an extracellular cell wall. This complex matrix of proteins and polysaccharides protects against adverse stresses and determines the shape of fungal cells. The polysaccharides of the fungal wall include 1,3-β-glucan and chitin, which are synthesized by membrane-bound synthases at the growing cell tip. A hallmark of filamentous fungi is the class V chitin synthase, which carries a myosin-motor domain. In the corn smut fungus Ustilago maydis, the myosin-chitin synthase Mcs1 moves to the plasma membrane in secretory vesicles, being delivered by kinesin-1 and myosin-5. The myosin domain of Mcs1 enhances polar secretion by tethering vesicles at the site of exocytosis. It remains elusive, however, how other cell-wall-forming enzymes are delivered and how their activity is coordinated post secretion. Here, we show that the U. maydis class VII chitin synthase and 1,3-β-glucan synthase travel in Mcs1-containing vesicles, and that their apical secretion depends on Mcs1. Once in the plasma membrane, anchorage requires enzyme activity, which suggests co-synthesis of chitin and 1,3-β-glucan polysaccharides at sites of exocytosis. Thus, delivery of cell-wall-forming enzymes in Mcs1 vesicles ensures local foci of fungal cell wall formation.
Abstract.
Le Cocq K, Gurr SJ, Hirsch PR, Mauchline TH (2016). Exploitation of endophytes for sustainable agricultural intensification. Molecular Plant Pathology, 18(3), 469-473.
Bebber DP, Castillo ÁD, Gurr SJ (2016). Modelling coffee leaf rust risk in Colombia with climate reanalysis data.
Philosophical Transactions of the Royal Society B: Biological Sciences,
371(1709).
Abstract:
Modelling coffee leaf rust risk in Colombia with climate reanalysis data
Many fungal plant diseases are strongly controlled by weather, and global climate change is thus likely to have affected fungal pathogen distributions and impacts. Modelling the response of plant diseases to climate change is hampered by the difficulty of estimating pathogen-relevant microclimatic variables from standard meteorological data. The availability of increasingly sophisticated high-resolution climate reanalyses may help overcome this challenge. We illustrate the use of climate reanalyses by testing the hypothesis that climate change increased the likelihood of the 2008–2011 outbreak of Coffee Leaf Rust (CLR, Hemileia vastatrix) in Colombia. We develop a model of germination and infection risk, and drive this model using estimates of leaf wetness duration and canopy temperature from the Japanese 55-Year Reanalysis (JRA-55).We model germination and infection as Weibull functions with different temperature optima, based upon existing experimental data. We find no evidence for an overall trend in disease risk in coffee-growing regions of Colombia from 1990 to 2015, therefore, we reject the climate change hypothesis. There was a significant elevation in predicted CLR infection risk from 2008 to 2011 compared with other years. JRA-55 data suggest a decrease in canopy surface water after 2008, which may have helped terminate the outbreak. The spatial resolution and accuracy of climate reanalyses are continually improving, increasing their utility for biological modelling. Confronting disease models with data requires not only accurate climate data, but also disease observations at high spatio-temporal resolution. Investment in monitoring, storage and accessibility of plant disease observation data are needed to match the quality of the climate data now available.
Abstract.
Fisher MC, Gow NAR, Gurr SJ (2016). Tackling emerging fungal threats to animal health, food security and ecosystem resilience.
Philosophical Transactions of the Royal Society B: Biological Sciences,
371(1709), 20160332-20160332.
Abstract:
Tackling emerging fungal threats to animal health, food security and ecosystem resilience
Emerging infections caused by fungi have become a widely recognized global phenomenon. Their notoriety stems from their causing plagues and famines, driving species extinctions, and the difficulty in treating human mycoses alongside the increase of their resistance to antifungal drugs. This special issue comprises a collection of articles resulting from a Royal Society discussion meeting examining why pathogenic fungi are causing more disease now than they did in the past, and how we can tackle this rapidly emerging threat to the health of plants and animals worldwide.
. This article is part of the themed issue ‘Tackling emerging fungal threats to animal health, food security and ecosystem resilience’.
Abstract.
Orr RJ, Murray PJ, Eyles CJ, Blackwell MSA, Cardenas LM, Collins AL, Dungait JAJ, Goulding KWT, Griffith BA, Gurr SJ, et al (2016). The North Wyke Farm Platform: effect of temperate grassland farming systems on soil moisture contents, runoff and associated water quality dynamics.
European Journal of Soil Science,
67(4), 374-385.
Abstract:
The North Wyke Farm Platform: effect of temperate grassland farming systems on soil moisture contents, runoff and associated water quality dynamics
© 2016 the Authors. European Journal of Soil Science published by John Wiley & Sons Ltd on behalf of British Society of Soil Science.The North Wyke Farm Platform was established as a United Kingdom national capability for collaborative research, training and knowledge exchange in agro-environmental sciences. Its remit is to research agricultural productivity and ecosystem responses to different management practices for beef and sheep production in lowland grasslands. A system based on permanent pasture was implemented on three 21-ha farmlets to obtain baseline data on hydrology, nutrient cycling and productivity for 2 years. Since then two farmlets have been modified by either (i) planned reseeding with grasses that have been bred for enhanced sugar content or deep-rooting traits or (ii) sowing grass and legume mixtures to reduce nitrogen fertilizer inputs. The quantities of nutrients that enter, cycle within and leave the farmlets were evaluated with data recorded from sensor technologies coupled with more traditional field study methods. We demonstrate the potential of the farm platform approach with a case study in which we investigate the effects of the weather, field topography and farm management activity on surface runoff and associated pollutant or nutrient loss from soil. We have the opportunity to do a full nutrient cycling analysis, taking account of nutrient transformations in soil, and flows to water and losses to air. The NWFP monitoring system is unique in both scale and scope for a managed land-based capability that brings together several technologies that allow the effect of temperate grassland farming systems on soil moisture levels, runoff and associated water quality dynamics to be studied in detail. Highlights: can meat production systems be developed that are productive yet minimize losses to the environment? the data are from an intensively instrumented capability, which is globally unique and topical. We use sensing technologies and surveys to show the effect of pasture renewal on nutrient losses. Platforms provide evidence of the effect of meteorology, topography and farm activity on nutrient loss.
Abstract.
Samalova M, Mï lida H, Vilaplana F, Bulone V, Soanes DM, Talbot NJ, Gurr SJ (2016). The β-1,3-glucanosyltransferases (Gels) affect the structure of the rice blast fungal cell wall during appressorium-mediated plant infection.
Cellular Microbiology,
19(3).
Abstract:
The β-1,3-glucanosyltransferases (Gels) affect the structure of the rice blast fungal cell wall during appressorium-mediated plant infection
The fungal wall is pivotal for cell shape and function, and in interfacial protection during host infection and environmental challenge. Here, we provide the first description of the carbohydrate composition and structure of the cell wall of the rice blast fungus Magnaporthe oryzae. We focus on the family of glucan elongation proteins (Gels) and characterize five putative β-1,3-glucan glucanosyltransferases that each carry the Glycoside Hydrolase 72 signature. We generated targeted deletion mutants of all Gel isoforms, that is, the GH72+, which carry a putative carbohydrate-binding module, and the GH72−Gels, without this motif. We reveal that M. oryzae GH72+GELs are expressed in spores and during both infective and vegetative growth, but each individual Gel enzymes are dispensable for pathogenicity. Further, we demonstrated that a Δgel1Δgel3Δgel4 null mutant has a modified cell wall in which 1,3-glucans have a higher degree of polymerization and are less branched than the wild-type strain. The mutant showed significant differences in global patterns of gene expression, a hyper-branching phenotype and no sporulation, and thus was unable to cause rice blast lesions (except via wounded tissues). We conclude that Gel proteins play significant roles in structural modification of the fungal cell wall during appressorium-mediated plant infection.
Abstract.
Che Omar S, Bentley MA, Morieri G, Preston GM, Gurr SJ (2016). Validation of Reference Genes for Robust qRT-PCR Gene Expression Analysis in the Rice Blast Fungus Magnaporthe oryzae. PLOS ONE, 11(8), e0160637-e0160637.
2015
Kilaru S, Schuster M, Latz M, Das Gupta S, Steinberg N, Fones H, Gurr SJ, Talbot NJ, Steinberg G (2015). A gene locus for targeted ectopic gene integration in Zymoseptoria tritici.
Fungal Genet Biol,
79, 118-124.
Abstract:
A gene locus for targeted ectopic gene integration in Zymoseptoria tritici.
Understanding the cellular organization and biology of fungal pathogens requires accurate methods for genomic integration of mutant alleles or fluorescent fusion-protein constructs. In Zymoseptoria tritici, this can be achieved by integrating of plasmid DNA randomly into the genome of this wheat pathogen. However, untargeted ectopic integration carries the risk of unwanted side effects, such as altered gene expression, due to targeting regulatory elements, or gene disruption following integration into protein-coding regions of the genome. Here, we establish the succinate dehydrogenase (sdi1) locus as a single "soft-landing" site for targeted ectopic integration of genetic constructs by using a carboxin-resistant sdi1(R) allele, carrying the point-mutation H267L. We use various green and red fluorescent fusion constructs and show that 97% of all transformants integrate correctly into the sdi1 locus as single copies. We also demonstrate that such integration does not affect the pathogenicity of Z. tritici, and thus the sdi1 locus is a useful tool for virulence analysis in genetically modified Z. tritici strains. Furthermore, we have developed a vector which facilitates yeast recombination cloning and thus allows assembly of multiple overlapping DNA fragments in a single cloning step for high throughput vector and strain generation.
Abstract.
Author URL.
Bebber DP, Gurr SJ (2015). Crop-destroying fungal and oomycete pathogens challenge food security.
Fungal Genet Biol,
74, 62-64.
Abstract:
Crop-destroying fungal and oomycete pathogens challenge food security.
Of the various crop pests and pathogens which blight our harvests, it is the fungi and oomycetes which are the most widely-dispersed groups and which lead the global invasion of agriculture. Here, we highlight the rapid growth in fungal and oomycete disease incidence and spread across the globe. We draw attention to the need for improved disease surveillance and for more sustainable agricultural intensification and consider the economic and humanitarian costs of fungal and oomycete diseases.
Abstract.
Author URL.
Gurr SJ, Hall A (2015). CuZn12: a novel antifungal and plant defence activator.
Fones HN, Steinberg G, Gurr SJ (2015). Measurement of virulence in Zymoseptoria tritici through low inoculum-density assays.
Fungal Genet Biol,
79, 89-93.
Abstract:
Measurement of virulence in Zymoseptoria tritici through low inoculum-density assays.
Hitherto, pathogenicity assays with mutants or wildtype variants of Zymoseptoria tritici have been based on pycnidial counts, following inoculation of host leaves with high density inoculum. Here, we present data which suggest that high inoculum densities may mask deficiencies in virulence due to symptom saturation. We describe a low inoculum-density method which obviates this problem. This method can also be used to (i) interrogate the process of lesion formation in Z. tritici (ii) determine whether individuals of the same or different genotypes co-operate or compete during the establishment of apoplastic infections (iii) dissect the determinants of virulence, by assessing a given strain's stomatal penetration efficiency (SPE), its ability to spread within the apoplast and its pycnidiation efficiency. Such methodology can thus be used to investigate the reasons underpinning attenuated virulence in mutant or avirulent wildtype strains.
Abstract.
Author URL.
Fones H, Gurr S (2015). The impact of Septoria tritici Blotch disease on wheat: an EU perspective. Fungal Genetics and Biology, 79, 3-7.
Falloon P, Bebber DP, Bryant J, Challinor A, Dessai S, Gurr S (2015). Using climate information to support crop breeding decisions and adaptation in agriculture.
World Agriculture,
5(1), 25-42.
Abstract:
Using climate information to support crop breeding decisions and adaptation in agriculture
Population growth in the next few decades will increase the need for food production, while the yields of major food crops could be impacted by the changing climate and changing threats from pests and pathogens. Crop breeding, both through conventional techniques, and GM assisted breeding could help meet these challenges, if adequately supported by appropriate information on the future climate. We highlight some of the major challenges for crop breeders and growers in the coming decades, and describe the main characteristics of crop breeding techniques and other adaptation options for agriculture. We review recent uses of climate information to support crop breeding decisions and make recommendations for how this might be improved. We conclude that there is significant potential for breeders to work more closely with climate scientists and crop modellers in order to address the challenges of climate change. It is not yet clear how climate information can best be used. Fruitful areas of investigation include: provision of climate information to identify key target breeding traits and develop improved success criteria (e.g. for heat/drought stress); identification of those conditions under which multiple stress factors (for example, heat stress, mid-season drought stress, flowering drought stress, terminal drought stress) are important in breeding programmes; use of climate information to inform selection of trial sites; identification of the range of environments and locations under which crop trials should be performed (likely to be a wider range of environments than done at present); identification of appropriate duration of trials (likely to be longer than current trials, due to the importance of capturing extreme events); and definition of appropriate methods for incorporating climate information into crop breeding programmes, depending on the specific needs of the breeding programme and the strengths and weaknesses of available approaches. Better knowledge is needed on climate-related thresholds important to crop breeders, for example on the frequency and severity of extreme climate events relevant to the product profile, or to help provide tailored climate analyses (particularly for extreme events). The uncertainties inherent in climate and impact projections provide a particular challenge for translating climate science into actionable outcomes for agriculture. Further work is needed to explore relevant social and economic assumptions such as the level and distribution of real incomes, changing consumption patterns, health impacts, impacts on markets and trade, and the impact of legislation relating to conservation, the environment and climate change.
Abstract.
2014
Grant-Downton DP, Terhem RB, Kapralov MV, Mehdi S, Rodriguez-Enriquez MJ, Gurr SJ, van Kan JAL, Frances M, Dewey FM (2014). A novel Botrytis species is associated with a newly emergent foliar disease in cultivated Hemerocallis. PLoS One, 9, e89272-e89272.
Bebber DP, Holmes T, Smith D, Gurr SJ (2014). Economic and physical determinants of the global distributions of crop pests and pathogens.
NEW PHYTOLOGIST,
202(3), 901-910.
Author URL.
Taylor C, Gurr S (2014). Fungal pathogenesis: Past, present and future. Fungal Biology Reviews, 28(1), 24-28.
Bagchi R, Gallery RE, Gripenberg S, Gurr SJ, Narayan N, Addis CE, Freckleton RP, Lewis OT (2014). Pathogens and insect herbivores drive rainforest plant diversity and composition. Nature
Bebber DP, Holmes T, Gurr SJ (2014). The global distribution of crop pests and pathogens.
Global Ecology and Biogeography,
23(12), 1398-1407.
Abstract:
The global distribution of crop pests and pathogens
© 2014 the Authors. The Journal of Physiology. © 2014 the Physiological Society.Aim to describe the patterns and trends in the spread of crop pests and pathogens around the world, and determine the socioeconomic, environmental and biological factors underlying the rate and degree of redistribution of crop-destroying organisms. Location Global. Methods Current country- and state-level distributions of 1901 pests and pathogens and historical observation dates for 424 species were compared with potential distributions based upon distributions of host crops. The degree of 'saturation', i.e. the fraction of the potential distribution occupied, was related to pest type, host range, crop production, climate and socioeconomic variables using linear models. Results More than one-tenth of all pests have reached more than half the countries that grow their hosts. If current trends continue, many important cropproducing countries will be fully saturated with pests by the middle of the century. While dispersal increases with host range overall, fungi have the narrowest host range but are the most widely dispersed group. The global dispersal of some pests has been rapid, but pest assemblages remain strongly regionalized and follow the distributions of their hosts. Pest assemblages are significantly correlated with socioeconomics, climate and latitude. Tropical staple crops, with restricted latitudinal ranges, tend to be more saturated with pests and pathogens than temperate staples with broad latitudinal ranges. We list the pests likely to be the most invasive in coming years. Main conclusions Despite ongoing dispersal of crop pests and pathogens, the degree of biotic homogenization of the globe remains moderate and regionally constrained, but is growing. Fungal pathogens lead the global invasion of agriculture, despite their more restricted host range. Climate change is likely to influence future distributions. Improved surveillance would reveal greater levels of invasion, particularly in developing countries.
Abstract.
2013
Bebber DP, Ramotowski MAT, Gurr SJ (2013). Crop pests and pathogens move poleward in a warming world.
Nature Climate Change,
3, 985-988.
Abstract:
Crop pests and pathogens move poleward in a warming world
Global food security is threatened by the emergence and spread of crop pests and pathogens. Spread is facilitated primarily by human transportation, but there is increasing concern that climate change allows establishment in hitherto unsuitable regions. However, interactions between climate change, crops and pests are complex, and the extent to which crop pests and pathogens have altered their latitudinal ranges in response to global warming is largely unknown. Here, we demonstrate an average poleward shift of 2.7±0.8 km yr−1 since 1960, in observations of hundreds of pests and pathogens, but with significant variation in trends among taxonomic groups. Observational bias, where developed countries at high latitudes detect pests earlier than developing countries at low latitudes, would result in an apparent shift towards the Equator. The observed positive latitudinal trends in many taxa support the hypothesis of global warming-driven pest movement.
Abstract.
Gurr SJ, Steel C, Dewey FM (2013). Lateral-flow devices to rapidly detect levels of stable Botrytis antigens in table and dessert wines. Am Journal of Oenology and Viticulture, 64, 291-295.
Samalova M, Johnson J, Illes M, Kelly S, Fricker M, Gurr SJ (2013). Nitric Oxide generated by the rice blast fungus Magnaporthe oryzae drives plant infection. New Phytologist(197), 202-207.
Samalova M, Meyer A, Gurr SJ, Fricker MD (2013). Robust anti-oxidant defences in the rice blast fungus Magnaporthe oryzae confer tolerance to the host oxidative burst. New Phytologist, 201(2), 556-573.
2012
Martinez DA, Oliver BG, Gräser Y, Goldberg JM, Li W, Martinez-Rossi NM, Monod M, Shelest E, Barton RC, Birch E, et al (2012). Comparative genome analysis of Trichophyton rubrum and related dermatophytes reveals candidate genes involved in infection.
mBio,
3(5), e00259-e00212.
Abstract:
Comparative genome analysis of Trichophyton rubrum and related dermatophytes reveals candidate genes involved in infection.
The major cause of athlete's foot is Trichophyton rubrum, a dermatophyte or fungal pathogen of human skin. To facilitate molecular analyses of the dermatophytes, we sequenced T. rubrum and four related species, Trichophyton tonsurans, Trichophyton equinum, Microsporum canis, and Microsporum gypseum. These species differ in host range, mating, and disease progression. The dermatophyte genomes are highly colinear yet contain gene family expansions not found in other human-associated fungi. Dermatophyte genomes are enriched for gene families containing the LysM domain, which binds chitin and potentially related carbohydrates. These LysM domains differ in sequence from those in other species in regions of the peptide that could affect substrate binding. The dermatophytes also encode novel sets of fungus-specific kinases with unknown specificity, including nonfunctional pseudokinases, which may inhibit phosphorylation by competing for kinase sites within substrates, acting as allosteric effectors, or acting as scaffolds for signaling. The dermatophytes are also enriched for a large number of enzymes that synthesize secondary metabolites, including dermatophyte-specific genes that could synthesize novel compounds. Finally, dermatophytes are enriched in several classes of proteases that are necessary for fungal growth and nutrient acquisition on keratinized tissues. Despite differences in mating ability, genes involved in mating and meiosis are conserved across species, suggesting the possibility of cryptic mating in species where it has not been previously detected. These genome analyses identify gene families that are important to our understanding of how dermatophytes cause chronic infections, how they interact with epithelial cells, and how they respond to the host immune response.
Abstract.
Author URL.
Fisher MC, Henk DA, Briggs CJ, Brownstein JS, Madoff LC, McCraw SL, Gurr SJ (2012). Emerging fungal threats to animal, plant and ecosystem health.
Nature,
484(7393), 186-194.
Abstract:
Emerging fungal threats to animal, plant and ecosystem health.
The past two decades have seen an increasing number of virulent infectious diseases in natural populations and managed landscapes. In both animals and plants, an unprecedented number of fungal and fungal-like diseases have recently caused some of the most severe die-offs and extinctions ever witnessed in wild species, and are jeopardizing food security. Human activity is intensifying fungal disease dispersal by modifying natural environments and thus creating new opportunities for evolution. We argue that nascent fungal infections will cause increasing attrition of biodiversity, with wider implications for human and ecosystem health, unless steps are taken to tighten biosecurity worldwide.
Abstract.
Author URL.
Samalova M, Johnson J, Illes M, Kelly S, Fricker M, Gurr S (2012). Nitric oxide generated by the rice blast fungus Magnaporthe oryzae drives plant infection. New Phytologist, 197(1), 207-222.
2011
Gurr S, Samalova M, Fisher M (2011). The rise and rise of emerging infectious fungi challenges food security and ecosystem health. Fungal Biology Reviews, 25(4), 181-188.
2010
Rodgers CJ, Blanford CF, Giddens SR, Skamnioti P, Armstrong FA, Gurr SJ (2010). Designer laccases: a vogue for high-potential fungal enzymes?.
Trends Biotechnol,
28(2), 63-72.
Abstract:
Designer laccases: a vogue for high-potential fungal enzymes?
Laccases are blue multicopper oxidases that catalyse the four-electron reduction of O(2) to water coupled with the oxidation of small organic substrates. Secreted basidiomycete white-rot fungal laccases orchestrate this with high thermodynamic efficiency, making these enzymes excellent candidates for exploitation as industrial oxidants. However, these fungi are less tractable genetically than the ascomycetes, which predominantly produce lower-potential laccases. We address the state-of-play regarding expression of high reduction potential laccases in heterologous hosts, and issues regarding enzyme glycosylation status. We describe the synergistic role of structural biology, particularly in unmasking structure-function relationships following genetic modification and their collective impact on laccase yields. Such recent research draws closer the prospect of industrial quantities of designer, fit-for-purpose laccases.
Abstract.
Author URL.
Spanu PD, Abbott JC, Amselem J, Burgis TA, Soanes DM, Stüber K, Ver Loren van Themaat E, Brown JKM, Butcher SA, Gurr SJ, et al (2010). Genome expansion and gene loss in powdery mildew fungi reveal tradeoffs in extreme parasitism.
Science,
330(6010), 1543-1546.
Abstract:
Genome expansion and gene loss in powdery mildew fungi reveal tradeoffs in extreme parasitism.
Powdery mildews are phytopathogens whose growth and reproduction are entirely dependent on living plant cells. The molecular basis of this life-style, obligate biotrophy, remains unknown. We present the genome analysis of barley powdery mildew, Blumeria graminis f.sp. hordei (Blumeria), as well as a comparison with the analysis of two powdery mildews pathogenic on dicotyledonous plants. These genomes display massive retrotransposon proliferation, genome-size expansion, and gene losses. The missing genes encode enzymes of primary and secondary metabolism, carbohydrate-active enzymes, and transporters, probably reflecting their redundancy in an exclusively biotrophic life-style. Among the 248 candidate effectors of pathogenesis identified in the Blumeria genome, very few (less than 10) define a core set conserved in all three mildews, suggesting that most effectors represent species-specific adaptations.
Abstract.
Author URL.
2009
Skamnioti P, Gurr SJ (2009). Against the grain: safeguarding rice from rice blast disease.
Trends Biotechnol,
27(3), 141-150.
Abstract:
Against the grain: safeguarding rice from rice blast disease.
Rice is the staple diet of more than three billion people. Yields must double over the next 40 years if we are to sustain the nutritional needs of the ever-expanding global population. Between 10% and 30% of the annual rice harvest is lost due to infection by the rice blast fungus Magnaporthe oryzae. Evaluation of genetic and virulence diversity of blast populations with diagnostic markers will aid disease management. We review the M. oryzae species-specific and cultivar-specific avirulence determinants and evaluate efforts towards generating durable and broad-spectrum resistance in single resistant cultivars or mixtures. We consider modern usage of fungicides and plant defence activators, assess the usefulness of biological control and categorize current approaches towards blast-tolerant genetically modified rice.
Abstract.
Author URL.
Petkov V, Ren Y, Saratovsky I, Pastén P, Gurr SJ, Hayward MA, Poeppelmeier KR, Gaillard J-F (2009). Atomic-scale structure of biogenic materials by total X-ray diffraction: a study of bacterial and fungal MnOx.
ACS Nano,
3(2), 441-445.
Abstract:
Atomic-scale structure of biogenic materials by total X-ray diffraction: a study of bacterial and fungal MnOx.
Biogenic materials are produced by microorganisms and are typically found in a nanophase state. As such, they are difficult to characterize structurally. In this report, we demonstrate how high-energy X-ray diffraction and atomic pair distribution function analysis can be used to determine the atomic-scale structures of MnO(x) produced by bacteria and fungi. These structures are well-defined, periodic, and species-specific, built of Mn-O(6) octahedra forming birnessite-type layers and todorokite-type tunnels, respectively. The inherent structural diversity of biogenic material may offer opportunities for practical applications.
Abstract.
Author URL.
Saratovsky I, Gurr SJ, Hayward MA (2009). The Structure of manganese oxide formed by the fungus Acremonium sp. strain KR21-2.
Geochimica et Cosmochimica Acta,
73(11), 3291-3300.
Abstract:
The Structure of manganese oxide formed by the fungus Acremonium sp. strain KR21-2
Manganese oxides are observed to form by the oxidation of aqueous solutions of Mn(II) catalyzed by the action of microorganisms. In contrast to the widely studied material produced by bacteria, manganese oxide phases produced by the action of fungi have received only limited attention. A detailed study of the MnOx material produced by the action of the fungus Acremonium KR21-2, utilizing X-ray diffraction, XANES, EXAFS and transmission electron microscopy is reported. The MnOx material is produced as small crystalline particles which adopt a todorokite-like tunnel structure, in striking contrast to previously reported microbial MnOx materials which adopt layered birnessite-type structures. ICPMS measurements reveal there are no templating metal ions present in the fungally mediated MnOx material, in contrast to analogous bacterially mediated material, suggesting these cations play a critical role in determining the structure of the material precipitated. A phylogenetic analysis places KR21-2 with other Acremonium species in the Hypocreales. © 2009 Elsevier Ltd. All rights reserved.
Abstract.
2008
Skamnioti P, Gurr SJ (2008). Cutinase and hydrophobin interplay: a herald for pathogenesis?.
Plant Signal Behav,
3(4), 248-250.
Abstract:
Cutinase and hydrophobin interplay: a herald for pathogenesis?
Surface-penetrating phytopathogenic fungi frequently form appressoria. These are specialised infection structures pivotal to fungal ingress into the host. Recently, we demonstrated that one member of a family of cutinases in Magnaporthe grisea is involved in surface sensing, mediating appressorium differentiation and penetration peg formation and hence facilitates host penetration. Cutinase2 serves as an upstream activator of cAMP/PKA and DAG/PKC signalling cascades and is essential for full virulence. Here, we speculate on the role of rice blast hydrophobins as surface interactors facilitating fungal cutinase activity.
Abstract.
Author URL.
Skamnioti P, Furlong RF, Gurr SJ (2008). Evolutionary history of the ancient cutinase family in five filamentous Ascomycetes reveals differential gene duplications and losses and in Magnaporthe grisea shows evidence of sub- and neo-functionalization.
New Phytol,
180(3), 711-721.
Abstract:
Evolutionary history of the ancient cutinase family in five filamentous Ascomycetes reveals differential gene duplications and losses and in Magnaporthe grisea shows evidence of sub- and neo-functionalization.
. The cuticle is the first barrier for fungi that parasitize plants systematically or opportunistically. Here, the evolutionary history is reported of the multimembered cutinase families of the plant pathogenic Ascomycetes Magnaporthe grisea, Fusarium graminearum and Botrytis cinerea and the saprotrophic Ascomycetes Aspergillus nidulans and Neurospora crassa. Molecular taxonomy of all fungal cutinases demonstrates a clear division into two ancient subfamilies. No evidence was found for lateral gene transfer from prokaryotes. The cutinases in the five Ascomycetes show significant copy number variation, they form six clades and their extreme sequence diversity is highlighted by the lack of consensus intron. The average ratio of gene duplication to loss is 2 : 3, with the exception of M. grisea and N. crassa, which exhibit extreme family expansion and contraction, respectively. Detailed transcript profiling in vivo, categorizes the M. grisea cutinases into four regulatory patterns. Symmetric or asymmetric expression profiles of phylogenetically related cutinase genes suggest subfunctionalization and neofunctionalization, respectively. The cutinase family-size per fungal species is discussed in relation to genome characteristics and lifestyle. The ancestry of the cutinase gene family, together with the expression divergence of its individual members provides a first insight into the drivers for niche differentiation in fungi.
Abstract.
Author URL.
Lee S, Gustafson G, Skamnioti P, Baloch R, Gurr S (2008). Host perception and signal transduction studies in wild-type Blumeria graminis f. sp hordei and a quinoxyfen-resistant mutant implicate quinoxyfen in the inhibition of serine esterase activity.
PEST MANAGEMENT SCIENCE,
64(5), 544-555.
Author URL.
Danac R, Ball L, Gurr SJ, Fairbanks AJ (2008). Synthesis of UDP-glucose derivatives modified at the 3-OH as potential chain terminators of beta-glucan biosynthesis.
Carbohydr Res,
343(6), 1012-1022.
Abstract:
Synthesis of UDP-glucose derivatives modified at the 3-OH as potential chain terminators of beta-glucan biosynthesis.
A series of UDP-D-glucose derivatives and precursors that have been modified at C-3 were synthesised from D-glucose as potential chain terminators of beta-glucan biosynthesis. None of the UDP-derivatives or the precursors tested displayed significant anti-fungal activity in a series of germination assays on the dermatophyte Trichophyton rubrum.
Abstract.
Author URL.
Skamnioti P, Furlong RF, Gurr SJ (2008). The fate of gene duplicates in the genomes of fungal pathogens.
Commun Integr Biol,
1(2), 196-198.
Abstract:
The fate of gene duplicates in the genomes of fungal pathogens.
Understanding how molecular changes underlie phenotypic variation within and between species is one of the main goals of evolutionary biology and comparative genetics. The recent proliferation of sequenced fungal genomes offers a unique opportunity to start elucidating the extreme phenotypic diversity in the Kingdom Fungi.1-4 We attempted to investigate the contribution of gene families to the evolutionary forces shaping the diversity of pathogenic lifestyles among the fungi.5 We studied a family of secreted enzymes which is present and expanded in all genomes of fungal pathogens sequenced to date and absent from the genomes of true yeasts.3,4 This family of cutinases6 predates the division between the two major fungal phyla, Ascomycota and Basidiomycota.5 We discuss our molecular phylogenetic analyses, the number and sequence diversity, and gene gains and losses of cutinase family members between five Ascomycetes: the phytopathogens Magnaporthe oryzae, Fusarium graminearum and Botrytis cinerea; and the model organisms Neurospora crassa and Aspergillus nidulans.5 the functional characterization of three members of the M. oryzae cutinase family,6-10 coupled with the regulatory subfunctionalization and neofunctionalization of most gene pairs5 provide the first justification for the retention of paralogs after duplication and for gene redundancy in the genomes of fungal pathogens.
Abstract.
Author URL.
2007
Skamnioti P, Henderson C, Zhang Z, Robinson Z, Gurr SJ (2007). A novel role for catalase B in the maintenance of fungal cell-wall integrity during host invasion in the rice blast fungus Magnaporthe grisea.
Mol Plant Microbe Interact,
20(5), 568-580.
Abstract:
A novel role for catalase B in the maintenance of fungal cell-wall integrity during host invasion in the rice blast fungus Magnaporthe grisea.
Asexual spores of the rice blast fungus germinate to produce a specialized and melanized infection structure, the appressorium, which is pivotal to successful plant penetration. To investigate whether Magnaporthe grisea counteracts the toxic burst of H2O2 localized beneath the site of attempted invasion, we examined the temporal expression of five candidate antioxidant genes. of these, the putatively secreted large subunit catalase CATB gene was 600-fold up-regulated in vivo, coincident with penetration, and moderately up-regulated in vitro, in response to exogenous H2O2. Targeted gene replacement of CATB led to compromised pathogen fitness; the catB mutant displayed paler pigmentation and accelerated hyphal growth but lower biomass, poorer sporulation, fragile conidia and appressoria, and impaired melanization. The catB mutant was severely less pathogenic than Guy 11 on barley and rice, and its infectivity was further reduced on exposure to H2O2. The wild-type phenotype was restored by the reintroduction of CATB into the catB mutant We found no evidence to support a role for CATB in detoxification of the host-derived H2O2 at the site of penetration. Instead, we demonstrated that CATB plays a part in strengthening the fungal wall, a role of particular importance during forceful entry into the host.
Abstract.
Author URL.
Danac R, Ball L, Gurr SJ, Muller T, Fairbanks AJ (2007). Carbohydrate chain terminators: rational design of novel carbohydrate-based antifungal agents.
Chembiochem,
8(11), 1241-1245.
Author URL.
Lees K, Roberts S, Skamnioti P, Gurr S (2007). Gene Microarray Analysis Using Angular Distribution Decomposition. Journal of Computational Biology, 14(1), 68-83.
Skamnioti P, Gurr SJ (2007). Magnaporthe grisea cutinase2 mediates appressorium differentiation and host penetration and is required for full virulence.
Plant Cell,
19(8), 2674-2689.
Abstract:
Magnaporthe grisea cutinase2 mediates appressorium differentiation and host penetration and is required for full virulence.
The rice blast fungus Magnaporthe grisea infects its host by forming a specialized infection structure, the appressorium, on the plant leaf. The enormous turgor pressure generated within the appressorium drives the emerging penetration peg forcefully through the plant cuticle. Hitherto, the involvement of cutinase(s) in this process has remained unproven. We identified a specific M. grisea cutinase, CUT2, whose expression is dramatically upregulated during appressorium maturation and penetration. The cut2 mutant has reduced extracellular cutin-degrading and Ser esterase activity, when grown on cutin as the sole carbon source, compared with the wild-type strain. The cut2 mutant strain is severely less pathogenic than the wild type or complemented cut2/CUT2 strain on rice (Oryza sativa) and barley (Hordeum vulgare). It displays reduced conidiation and anomalous germling morphology, forming multiple elongated germ tubes and aberrant appressoria on inductive surfaces. We show that Cut2 mediates the formation of the penetration peg but does not play a role in spore or appressorium adhesion, or in appressorial turgor generation. Morphological and pathogenicity defects in the cut2 mutant are fully restored with exogenous application of synthetic cutin monomers, cAMP, 3-isobutyl-1-methylxanthine, and diacylglycerol (DAG). We propose that Cut2 is an upstream activator of cAMP/protein kinase a and DAG/protein kinase C signaling pathways that direct appressorium formation and infectious growth in M. grisea. Cut2 is therefore required for surface sensing leading to correct germling differentiation, penetration, and full virulence in this model fungus.
Abstract.
Author URL.
Gurr SJ, Fairbanks A (2007). Oligosaccharide biosynthetic fungal wall inhibitors.
Muller T, Danac R, Ball L, Gurr SJ, Fairbanks AJ (2007). Synthesis of UDP-GlcNAc derivatives modified at OH-4 as potential chain-terminators of chitin biosynthesis.
Tetrahedron Asymmetry,
18(11), 1299-1307.
Abstract:
Synthesis of UDP-GlcNAc derivatives modified at OH-4 as potential chain-terminators of chitin biosynthesis
A series of UDP-GlcNAc derivatives and precursors that have been modified at the 4-position were synthesised from N-acetyl glucosamine as potential chain terminators of chitin biosynthesis. None of the UDP-derivatives or the precursors tested displayed any significant anti-fungal activity in cell adhesion or germination assays on the dermatophyte Trichophyton rubrum. © 2007 Elsevier Ltd. All rights reserved.
Abstract.
2006
Zelinger E, Hawes CR, Gurr SJ, Dewey FM (2006). Attachment and adhesion of conidia of Stagonospora nodorum to natural and artificial surfaces.
Physiological and Molecular Plant Pathology,
68(4-6), 209-215.
Abstract:
Attachment and adhesion of conidia of Stagonospora nodorum to natural and artificial surfaces
Attachment and adhesion of conidia of a wheat-isolate of Stagonospora nodorum to leaf and artificial surfaces was studied. Attachment of conidia was a non-viable process, separate from adhesion, that occurred rapidly and irreversibly. Attachment involved conidial-surface carbohydrates and was partially influenced by surface hydrophobicity. The subsequent adhesion, via the secretion of extracellular matrix from conidia, was a viable process that induced the complete cover of conidia in response to wheat leaf surface components containing epi-cuticular wax and to a lesser extent to barley but inducing only partial covering on glass. Results suggest that specific surface components from the compatible host promote rapid attachment and adhesion of S. nodorum conidia. © 2006 Elsevier Ltd. All rights reserved.
Abstract.
Carver TLW, Gurr SJ (2006). Filamentous Fungi on Plant Surfaces. In (Ed) Biology of the Plant Cuticle, 368-397.
Gurr SJ, Carver TLW (2006). Filamentous fungi on plant surfaces. In Reiderer M (Ed) Biology of Plant Cuticles, Blackwell Publishing, 112-132.
2005
Gurr SJ, Rushton PJ (2005). Engineering plants with increased disease resistance: how are we going to express it?.
Trends Biotechnol,
23(6), 283-290.
Abstract:
Engineering plants with increased disease resistance: how are we going to express it?
Precise control of transgene expression is pivotal to the engineering of plants with increased disease resistance. Many early attempts to boost disease resistance used constitutive overexpression of defence components but frequently this resulted in poor quality plants. It is now clear that the extensive cellular reprogramming associated with defence will reduce yields if uncontrolled defence reactions are activated in uninfected cells. Therefore, for many strategies pathogen-inducible promoters might be the most useful as they limit the cost of resistance by restricting expression to infection sites. Although progress to date has been hindered by a lack of suitable promoters, new research should reveal more potentially useful native promoters. Additionally, the first steps towards 'designer' synthetic promoters have proved encouraging.
Abstract.
Author URL.
Gurr SJ, Rushton PJ (2005). Engineering plants with increased disease resistance: what are we going to express?.
Trends Biotechnol,
23(6), 275-282.
Abstract:
Engineering plants with increased disease resistance: what are we going to express?
To engineer plants with increased and durable disease resistance using transgenic technologies we must address two questions. First, what gene or genes do we want to express to improve disease resistance, and second, how are we going to express these genes so that crop yields are actually increased? Emerging technologies are providing us with a plethora of candidate genes that might lead to enhanced crop protection through genetic engineering. These genes can come from plants, from pathogens or from other organisms and several strategies for their manipulation show promise. Here, we discuss recent advances and consider future perspectives for producing plants with durable disease resistance.
Abstract.
Author URL.
Zhang Z, Henderson C, Perfect E, Carver TLW, Thomas BJ, Skamnioti P, Gurr SJ (2005). Of genes and genomes, needles and haystacks: Blumeria graminis and functionality.
Mol Plant Pathol,
6(5), 561-575.
Abstract:
Of genes and genomes, needles and haystacks: Blumeria graminis and functionality.
SUMMARY Here, we consider the barley powdery mildew fungus, Blumeria graminis (DC Speer) f.sp. hordei (Marchal), and review recent research which has added to our understanding of the biology and molecular biology which underpins the asexual life cycle of this potentially devastating pathogen. We focus on the early stages of the host-pathogen interaction and report current understanding in the areas of leaf perception, fungal signal transduction and host-imposed oxidative stress management. Through this, it is becoming increasingly clear how closely and subtly both sides of the relationship are regulated. Collectively, however, this review highlights the high degree of complexity in working with an obligate parasite. Our experiences suggest that we would make more efficient progress towards understanding the basis of susceptibility and resistance to this true obligate biotroph if its genome sequence was available.
Abstract.
Author URL.
2004
Gurr SJ, Mukherjee S, Roberts SJ (2004). A consistency-based method for the selection of differentially expressed genes from microarray data.
Zelinger E, Hawes CR, Gurr SJ, Dewey FM (2004). An immunocytochemical and ultra-structural study of the extracellular matrix produced by germinating spores of Stagonospora nodorum on natural and artificial surfaces.
Physiological and Molecular Plant Pathology,
65(3), 123-135.
Abstract:
An immunocytochemical and ultra-structural study of the extracellular matrix produced by germinating spores of Stagonospora nodorum on natural and artificial surfaces
The temporal secretion and ultra-structure of the extracellular matrix (ECM) produced by conidia and germ-tubes of Stagonospora nodorum on wheat and other surfaces during the first 6 h post inoculation was examined. To visualize the ECM, a combination of immunological, histochemical and ultra-structural methods were employed. Lectins and two monoclonal antibodies were used. One antibody specifically recognised a conidial surface protein and the other recognised a carbohydrate epitope present on an antigen in the ECM and the germ-tube cell wall. Three major phases of ECM release on the leaf surface and two on the artificial surfaces were identified: (a) commencing less than 15 min after contact of the conidium with the host, composed of a carbohydrate core and protein halo, (b) coinciding with the emergence and growth of germ-tubes, composed of proteins and carbohydrates, (c) spreading around the conidia after germ-tube production, not seen on the artificial surfaces. Results indicated that the ECM of conidia and germ-tubes differ in thickness and composition and that the intensity of conidial ECM was affected by the surface properties of the substrata in contact. In addition, maintenance of the ECM in a hydrated state was found to be essential for study of its ultra-structure highlighting the importance of using a diversity of methods to visualize the ECM. © 2005 Elsevier Ltd. All rights reserved.
Abstract.
Zhang Z, Henderson C, Gurr SJ (2004). Blumeria graminis secretes an extracellular catalase during infection of barley: potential role in suppression of host defence.
Mol Plant Pathol,
5(6), 537-547.
Abstract:
Blumeria graminis secretes an extracellular catalase during infection of barley: potential role in suppression of host defence.
SUMMARY the obligate biotrophic fungal pathogen of barley, Blumeria graminis f.sp. hordei (Bgh), elicits a burst of H(2)O(2) in its host barley at sites of germ tube invasion. To evaluate whether this specialized pathogen has any antioxidant response to this oxidative burst, the Bgh catB gene was characterized and transcript-profiled together with other genes implicated in the management of oxidative stress (catalase-peroxidase, cpx; glutathione peroxidase, gpx; superoxide dismutase, sod1) and in comparison with the constitutively expressed Bghbeta-tubulin and elongation factor1 (ef1) genes. Gel-based and real-time RT-PCR revealed enhanced numbers of catB transcripts at mature primary germ tube and appressorium germ tube (AGT) stages in a susceptible host. Moreover, an anti-CATB polyclonal antibody, from Aspergillus fumigatus, which recognizes both native and recombinant Bgh CATB, revealed an intense circle of immunofluorescence at the host-pathogen interface at the AGT tip and within the halo area surrounding the host papilla. A new diaminobenzidine-based 'scavenger' assay revealed areas of H(2)O(2) clearing at sites of fungal invasion, provoking speculation that Bgh catalase activity may contribute to pathogenicity in Bgh.
Abstract.
Author URL.
Gurr SJ, Fujita K, Suzuki T, Kunoh H, Carver TLW, Thomas B (2004). Induced inaccessibility in barley cells exposed to extracellular material
released by non-pathogenic powdery mildew conidia.
Physiological and Molecular Plant Pathology,
64, 169-178.
Abstract:
Induced inaccessibility in barley cells exposed to extracellular material
released by non-pathogenic powdery mildew conidia
Before germinating, conidia of Blumeria graminis f. sp. hordei (Bgh) and tritici (Bgt) and Erysiphe pisi (Ep) rapidly released extracellular material (ECM) onto barley coleoptile cells. More was released if full rather than partial cell contact was made. Within 5–6.5 h of receiving ECM from Ep or Bgt (non-pathogens) cells showed induced inaccessibility to challenger Bgh. This effect was greater for Ep than Bgt where full contact was required. Abiotic particles and ECM from Bgh did not affect cells' accessibility to subsequent challenger attack by Bgh. This induced inaccessibility must be due to active component(s) within conidial ECM.
Abstract.
Henderson C, Lee S, Gurr SJ (2004). Pathogens: the plight of plants.
Genome Biol,
5(3).
Abstract:
Pathogens: the plight of plants.
A report on the British Society for Plant Pathology Presidential meeting 'Plant pathogen genomics - from sequence to application', University of Nottingham, UK, 15-18 December 2003.
Abstract.
Author URL.
2003
Vincent KA, Kadodia SM, Armstrong FA, Gurr SJ (2003). Electrochemical insights into inhibition of multi-copper oxidases. Journal of Inorganic Biochemistry, 96(1), 244-244.
Gurr SJ, Mukherjee SN, Sykacek P, Roberts SJ (2003). Gene ranking by bootstrapped P-values. SIGKDD explorations : newsletter of the Special Interest Group (SIG) on Knowledge Discovery & Data Mining, 52, 14-20.
Wheeler IE, Hollomon DW, Gustafson G, Mitchell JC, Longhurst C, Zhang Z, Gurr SJ (2003). Quinoxyfen perturbs signal transduction in barley powdery mildew (Blumeria graminis f.sp. hordei).
Mol Plant Pathol,
4(3), 177-186.
Abstract:
Quinoxyfen perturbs signal transduction in barley powdery mildew (Blumeria graminis f.sp. hordei).
SUMMARY Quinoxyfen is a protectant fungicide which controls powdery mildew diseases by interfering with germination and/or appressorium formation. Mutants of barley powdery mildew, Blumeria graminis f.sp. hordei, which are resistant to quinoxyfen produce fewer conidia, which germinate and form appressoria more promiscuously than do the prolific numbers of wild-type spores. This suggests that resistance bypasses host recognition signals. RT-PCR profiles of signal transduction genes, recorded during wild-type germling morphogenesis, reveals that quinoxyfen alters the accumulation of Protein Kinase C (pkc), pkc-like and catalytic subunit of Protein Kinase a (cpka) transcripts. Differential display-reverse transcription PCR identified a gene transcript in wild-type conidia that was absent, or much less abundant, in conidia from quinoxyfen-resistant mutants. This mRNA was not detectable 24 h after wild-type conidia were inoculated on to barley. It encodes a GTPase activating protein (GAP), which may interact with a small molecular weight Ras-type GTP binding protein. In the presence of quinoxyfen, the gap mRNA remains throughout germling morphogenesis. The involvement of GAP in resistance suggests that quinoxyfen inhibits mildew infection by disrupting early cell signalling events.
Abstract.
Author URL.
2002
Zhang Z, Gurr SJ (2002). A "step down" PCR-based technique for walking into and the subsequent direct-sequence analysis of flanking genomic DNA.
Methods Mol Biol,
192, 343-350.
Author URL.
Gurr SJ, Zhang Z (2002). A “step down” PCR-based technique for walking into and the direct sequence analysis of flanking genomic DNA. In Chen B-Y (Ed) PCR protocols, NJ: Humana Press, 343-350.
Gurr SJ, Chaure P, Spanu P (2002). DNA-mediated transformation of Erysiphe graminis. In Belanger RR, Dick AJ, Bushnell WR (Eds.) The Powdery Mildews: a comprehensive treatise, USA: American Phytological Society, 100-107.
Hiscock SJ, Bown D, Gurr SJ, Dickinson HG (2002). Serine esterases are required for pollen tube penetration of the stigma in Brassica.
Sexual Plant Reproduction,
15(2), 65-74.
Abstract:
Serine esterases are required for pollen tube penetration of the stigma in Brassica
We have investigated the diversity of serine esterases in pollen and stigma tissues of Brassica napus and the role of these enzymes in pollen germination and pollen tube penetration of the stigma. The serine esterase-specific inhibitor diisopropyl fluorophosphate was used as a probe in a tritiated form, [3H]-DIPF, to determine the number and diversity of serine esterases in crude protein extracts from pollen and stigma. Seven serine esterases were identified in pollen and at least seven serine esterases were identified in stigma. The most abundant enzymes had molecular weights of 30-50 kDa. In the pollen extract a serine esterase was detected with the same molecular weight, 22 kDa, as an esterase previously shown to be a cutinase. Only one serine esterase (40 kDa) appeared to be shared between pollen and stigma extracts. Butyrate esterase activity in pollen and stigma extracts was assayed using p-nitrophenyl butyrate (PNB), an ester substrate frequently used in 'cutinase' assays. Total PNBase activity in pollen and stigma extracts was shown to be significantly reduced by the serine esterase inhibitors DIPF and ebelactone B. When DIPF and ebelactone B were applied to stigmas prior to pollination, pollen germination was not significantly affected but, at the highest inhibitor concentrations, up to 70% of germinating pollen tubes failed to penetrate the stigma surface. These data demonstrate that serine esterases, most probably cutinase(s), are required for pollen tube penetration of the dry cuticularised Brassica stigma.
Abstract.
Gurr SJ, Zhang Z, Priddey G (2002). The barley powdery mildew protein kinase C gene, pkc1 and pkc‐like gene, are differentially expressed during morphogenesis.
Molecular Plant Pathology,
2(6), 327-337.
Abstract:
The barley powdery mildew protein kinase C gene, pkc1 and pkc‐like gene, are differentially expressed during morphogenesis
Protein kinase C agonist assays revealed the phorbol ester, phorbol 12‐myristate 13‐acetate, invoked germling morphogenesis and enhanced PKC activity in Blumeria graminis. No antagonist of mildew PKC activity was found but the data fuelled a hunt for powdery mildew pkc genes. Oligonucleotides, designed on the basis of conserved ATP‐binding and kinase domains within the catalytic core of eukaryotic protein kinase proteins, were used as primers to amplify chromosomal and cDNA fragments from the barley powdery mildew fungus graminis. Three kinase gene fragments were isolated (pkc1, pkc‐like and cpka) and the full length genomic sequences of the mildew pkc and pkc‐like genes were determined by ‘step down’ PCR. RT‐PCR transcript profiles showed the three genes to be differentially regulated during germling morphogenesis.
Abstract.
Gurr SJ, Carver TLW, Green JR (2002). The formation and function of infection and feeding structures. In Belanger RR, Dick AJ, Bushnell WR (Eds.) The Powdery Mildews: a comprehensive treatise, St Paul, USA: American Phytological Society Press, 66-83.
2001
Zhang Z, Gurr SJ (2001). Expression and sequence analysis of the Blumeria graminis mitogen-activated protein kinase genes, mpk1 and mpk2.
Gene,
266(1-2), 57-65.
Abstract:
Expression and sequence analysis of the Blumeria graminis mitogen-activated protein kinase genes, mpk1 and mpk2.
Mitogen-activated protein (MAP) kinases represent a group of serine/threonine kinases which play a pivotal role in signal transduction processes in eukaryotic cells. Using degenerate PCR primer design based on published and aligned MAP kinase sequences we have cloned and characterised two MAP kinase genes from the barley powdery mildew fungus, Blumeria graminis. We have utilised 'step down' PCR to attain the full length mildew genomic clones. The single-copy genes, named mpk1 and mpk2, encode putative proteins of 356 and 410 amino acids and carry three and four introns, respectively. Expression studies, using RT-PCR, reveal a differing pattern of tissue gene expression with mpk1 and mpk2 during germling morphogenesis and this is compared with the constitutive expression of the 'control' beta-tubulin gene.
Abstract.
Author URL.
Gurr SJ, McPherson MJ, Bowles DJ, Atkinson HJ (2001). Plant parasitic nematode control.
Jones H, Whipps JM, Gurr SJ (2001). The tomato powdery mildew fungus Oidium neolycopersici.
Mol Plant Pathol,
2(6), 303-309.
Abstract:
The tomato powdery mildew fungus Oidium neolycopersici.
UNLABELLED: summary Pathogen: Powdery mildew fungus; Ascomycete although sexual stage is yet to be found; an obligate biotroph. IDENTIFICATION: Superficial mycelium with hyaline hyphae; unbranched erect conidiophores; conidia, ellipsoid-ovoid or doliform, 22-46 x 10-20 microm, lack fibrosin bodies; conidia formed singly, rarely in short chains of 2-6 conidia; appressoria lobed to multilobed, rarely nipple-shaped. Pseudoidium species. HOST RANGE: Broad, reported to attack over 60 species in 13 plant families, particularly members of the Solanaceae and Curcubitaceae. SYMPTOMS: Powdery white lesions on all aerial plant parts except the fruit. In severe outbreaks the lesions coalesce and disease is debilitating. Agronomic importance: Extremely common in glasshouse tomatoes world wide but increasing in importance on field grown tomato crops. CONTROL: Chemical control and breeding programmes for disease resistance.
Abstract.
Author URL.
2000
Baker SJ, Newton AC, Gurr SJ (2000). Cellular characteristics of temporary partial breakdown of mlo-resistance in barley to powdery mildew.
Physiological and Molecular Plant Pathology,
56(1), 1-11.
Abstract:
Cellular characteristics of temporary partial breakdown of mlo-resistance in barley to powdery mildew
When water-stress is relieved, powdery mildew (Erysiphe graminis f.sp. hordei) infection increases on both Mlo-susceptible and mlo-resistant spring barley cultivars. The breakdown is temporary and is determined by the genetic background rather than the specific resistance allele. The relief of water-stress time-point for maximum mildew infection frequency on mlo-resistant barley is approximately 7 h post-inoculation. The degree of breakdown varies with epidermal cell type; increased infection frequency is greatest on short followed by long and adjacent epidermal cell types, rather than on the stomatal subsidiary cells with which occasional colonies are typically associated. Infection frequency on the short cells of mlo-resistant cv. Atem increases from less than 1% under a non-stressed watering regime to more than 10% after a relief of waterstress at 7 h post-inoculation. Following haustorium formation, colonies develop and reach sporulation within 7 days post-inoculation. In host epidermal cells, the extent of cross-linked protein at interaction sites is reduced under conditions of water-stress or stress-relief. Cross-linked protein is reduced in terms of the frequency of occurrence at primary germ tube interaction sites 7 h post-inoculation and the deposition size at appressorial germ tube interaction sites 24 h post-inoculation. This indicates a delayed or reduced defence response during the recovery period. These data demonstrate a differential cellular response to powdery mildew in barley genotypes prone to resistance expression breakdown following relief of water-stress.
Abstract.
Karpovich-Tate N, Dewey FM, Smith EJ, Lund VJ, Gurr PA, Gurr SJ (2000). Detection of fungi in sinus fluid of patients with allergic fungal rhinosinusitis.
Acta Otolaryngol,
120(2), 296-302.
Abstract:
Detection of fungi in sinus fluid of patients with allergic fungal rhinosinusitis.
We aim to develop a rapid, accurate and sensitive diagnostic assay with which to detect the surface antigens of fungi thought to be involved in allergic fungal rhinosinusitis (AFRS), by assessing the usefulness of immunofluorescence microscopy (IMF) and enzyme linked immuno-absorbent assays (ELISA). The age, sex, clinical symptoms and signs, imaging (CT and/or MRI), microbiological subculture data, sinus contents, blood eosinophilia, aspergillosis precipitins, radioallergoabsorbent technology (RAST) for fungal allergens and histopathology were performed on individuals undergoing endoscopic sinus surgery for suspected AFRS. Thirteen patients were examined, and five monoclonal antibodies raised to the surface washings of various fungi were found to recognize and differentiate between fungal species implicated in sinus disease, i.e. Aspergillus niger, Alternaria alternata, Cochliobolus lunata, Penicillium expansum and Cladosporium species. The IMF microscopy proved to be a useful assay to distinguish visually between the cultured fungi, but was less useful for visualization of fungi in the patient samples. However, ELISA assays with 5 monoclonal antibodies gave clear and unambiguous data as to the presence of certain fungi within the patient samples. There is good correlation between the ELISA data and the pathology findings. This preliminary study suggests that both IMF and ELISA techniques may offer an important advance in this area.
Abstract.
Author URL.
Zhang Z, Hall A, Perfect E, Gurr SJ (2000). Differential expression of two Blumeria graminis chitin synthase genes.
Mol Plant Pathol,
1(2), 125-138.
Abstract:
Differential expression of two Blumeria graminis chitin synthase genes.
Abstract Two Blumeria graminis chitin synthase genes, designated BgChs1 and BgChs2 were cloned and characterized following the synthesis and use of degenerate PCR primers designed to the conserved regions of fungal chitin synthase (Chs) genes. Their sequences revealed high similarity with the Chs genes previously cloned from other fungi and placed BgChs1 and BgChs2 with the classes I and V, respectively. Each gene was present as a single copy within the barley powdery mildew genome. Semi-quantitative RT-PCR assays revealed BgChs1 to be up-regulated at both the primary germ tube (PGT) and appressorial germ tube (AGT) stages of differentiation whilst the BgChs2 transcript was up-regulated at the PGT stage. The B. graminisbeta-tubulin gene was used as a control for all RT-PCR reactions. The BgChs1 transcript was some 30 fold less abundant than the beta-tubulin transcript and BgChs2 was some 30 fold rarer than the BgChs1 transcript. The effects of the chitin substrate analogues nikkomycin Z and polyoxin D on conidial morphogenesis were assessed. These nucleoside peptide inhibitors did not affect germination but both polyoxin D and nikkomycin Z treatment led to a large population of abnormally swollen 'balloon-shaped' AGTs, whilst by 12 h after inoculation polyoxin treatment caused the swollen germ tubes to burst.
Abstract.
Author URL.
Gurr SJ, Kinane JS, Bindslev L, Hall AA, Oliver R (2000). Evidence that the cAMP Pathway Controls Emergence of Both Primary and Appressorial Germ Tubes of Barley Powdery Mildew. Molecular Plant-Microbe Interactions, 13, 494-502.
Jones HE, Whipps JM, Thomas BJ, Carver TL, Gurr SJ (2000). Initial events in the colonisation of tomatoes by Oidium lycopersici, a distinct powdery mildew fungus of Lycopersicon species. Botany, 78(10), 1361-1366.
Jones HE, Whipps JM, Thomas BJ, Carver TLW, Gurr SJ (2000). Initial events in the colonisation of tomatoes by Oidium lycopersici, a distinct powdery mildew fungus of Lycopersicon species.
Canadian Journal of Botany,
78(10), 1361-1366.
Abstract:
Initial events in the colonisation of tomatoes by Oidium lycopersici, a distinct powdery mildew fungus of Lycopersicon species
The rDNA intergenic spacer sequence of Oidium lycopersici (ana.: Cooke & Massee 1888. emend. Noordeloos and Loerakker 1989, emend. Mieslerova and Lebeda 1999) was determined and compared with the sequences of other powdery mildews. This pathogen was shown to be distinct from other powdery mildew fungi found on tomato, but it exhibited a close similarity to Erysiphe aquilegiae var. ranunculi. The initial events involved in the germination of conidia and subsequent formation of the appressorium in the newly described powdery mildew of tomato. O. lycopersici. were studied by light and scanning electron microscopy. Scanning electron microscopy revealed the conidial coat to be smooth to slightly rugose and the appressoria to be multilobed and attached to the host by a mucilaginous pad of extracellular material.
Abstract.
Hall AA, Gurr SJ (2000). Initiation of appressorial germ tube differentiation and appressorial hooking: Distinct morphological events regulated by cAMP signalling in Blumeria graminis f.sp. hordei.
Physiological and Molecular Plant Pathology,
56(1), 39-46.
Abstract:
Initiation of appressorial germ tube differentiation and appressorial hooking: Distinct morphological events regulated by cAMP signalling in Blumeria graminis f.sp. hordei
Appressorial differentiation by conidia of the barley powdery mildew fungus, Blumeria graminis f.sp.hordei, is dependent on perception of multiple leaf-derived signals. Recently, we have demonstrated that cAMP signalling and PKA play an important, but complex, role during early B. graminis conidial development. Here, we demonstrate that a rise in cAMP levels correlates with conidial differentiation on the barley leaf surface. No change in cAMP levels is observed when conidia fail to differentiate on a non-inductive surface. Moreover, the cAMP levels appear to both increase and decrease during conidial development on barley leaves, suggesting that appressorial differentiation requires differential activation of the cAMP-signalling pathway. In addition, we have dissected the time periods over which cAMP, the cAMP analogue 8-Br-cAMP, and the PKA inhibitor H89, are able to affect conidial differentiation. This reveals that H89 is only active prior to 4 h post-inoculation, corresponding to the initiation of appressorial germ tube development, whereas only cAMP and 8-Br-cAMP inhibit the later process of appressorial hooking, at 4-8 h post-inoculation. Thus, we provide data that supports a model in which cAMP signalling is required to be active to trigger initiation of appressorial germ tube development and inactive to allow subsequent appressorial germ tube hooking.
Abstract.
Gurr SJ, Hall A, Zhang Z, Carver TLW (2000). Powdery Mildews. In (Ed) Encyclopedia of Microbiology, Academic Press, 801-808.
Chaure P, Gurr SJ, Spanu P (2000). Stable transformation of erysiphe graminis an obligate biotrophic pathogen of barley.
Nat Biotechnol,
18(2), 205-207.
Abstract:
Stable transformation of erysiphe graminis an obligate biotrophic pathogen of barley.
Barley powdery mildew, Erysiphe graminis f.sp. hordei, is an obligate biotrophic pathogen and as such cannot complete its life cycle without a living host. The inability to transform this fungus and manipulate its genome has constrained research towards understanding its life cycle and pathogenicity. Here we describe an in planta transformation system based on delivery of DNA using a gold-particle gun and selection using benomyl or bialaphos. Using this method, we consistently obtained stable transformants with efficiencies comparable to other filamentous fungi. Stable expression of the beta-glucuronidase in E. graminis was demonstrated by co-transforming the uidA gene with the selectable markers.
Abstract.
Author URL.
Zhang Z, Gurr SJ (2000). Walking into the unknown: a 'step down' PCR-based technique leading to the direct sequence analysis of flanking genomic DNA.
Gene,
253(2), 145-150.
Abstract:
Walking into the unknown: a 'step down' PCR-based technique leading to the direct sequence analysis of flanking genomic DNA.
We describe a novel and efficient PCR-based technique for walking into unknown flanking genomic DNA without recourse to protracted laborious library screening for overlapping sequences. This two component 'hot start' and 'step down' PCR method uses 6x1 microg of genomic DNA (ca 20kb in length) restricted with six different endonucleases and ligated to adaptors with the inclusion of two further restriction enzymes to prevent self-ligation. This allowed us to walk, in a single step, up to 6kb into flanking DNA and gave sufficient PCR products for up to 200 different walking experiments. This technology enabled us to clone and characterize the previously elusive 5' sequence of the barley powdery mildew chitin synthase gene, BgChs2, which includes a myosin motor-like sequence fused to a type V chitin synthase gene.
Abstract.
Author URL.
1999
Dewey FM, Li Wong Y, Seery R, Hollins TW, Gurr SJ (1999). Bacteria associated with Stagonospora (Septoria) nodorum increase pathogenicity of the fungus.
New Phytologist,
144(3), 489-497.
Abstract:
Bacteria associated with Stagonospora (Septoria) nodorum increase pathogenicity of the fungus
In studies with a laboratory isolate of the fungal pathogen Stagonospora (Septoria) nodorum three different isolates of bacteria were closely associated with the fungus. Bacteria were also closely associated with fresh isolates of S. nodorum obtained from artificially and naturally infected field material. Although a range of bacteria was isolated, only one type of bacterium was found to be associated with each isolate of S. nodorum. In co-inoculation studies with pycnidiospores of the fungus on detached leaves, some of the bacterial isolates significantly increased the pathogenicity of the fungus, particularly Xanthomonas maltophilia, Sphingobacterium multivorum, Enterobacter agglomerans and Erwinia amylovora. Evidence is presented indicating that one of the ways that the 'helper bacteria' may assist in the establishment of infections is by the production of lipases that were not detected in germinating fungal spores.
Abstract.
Hall AA, Bindslev L, Rouster J, Rasmussen SW, Oliver RP, Gurr SJ (1999). Involvement of cAMP and protein kinase a in conidial differentiation by Erysiphe graminis f. sp. hordei.
Mol Plant Microbe Interact,
12(11), 960-968.
Abstract:
Involvement of cAMP and protein kinase a in conidial differentiation by Erysiphe graminis f. sp. hordei.
Erysiphe graminis f. sp. hordei, the causal agent of barley powdery mildew, is an obligate biotroph. On arrival on the host, a primary germ tube (PGT) emerges from the conidium. An appressorial germ tube (AGT) then appears, forms an appressorium, and effects host penetration. Such developmental precision may be due to multiple, plant-derived signals and to endogenous tactile and chemical signals. The transduction mechanism remains obscure. The isolation of an expressed sequence tag (EST) homologue of the catalytic subunit of cyclic AMP (cAMP)-dependent protein kinase a (PKA) enabled the corresponding gene to be characterized and the transcript to be identified in conidia and in PGT and AGT stage spores. cAMP-dependent PKA activity was detected in ungerminated conidia. These data suggest that PKA and cAMP are involved in conidial development. To substantiate this we exploited the responses of developing conidia to various surfaces, including exposure to the host leaf (fully inductive to AGT formation), cellulose membrane (semi-inductive), and glass (non-inductive). Assessment of fungal development, following application of exogenous cAMP or cAMP analogues, revealed that, at different concentrations and on different surfaces, cAMP either promoted or inhibited conidial differentiation. Various PKA inhibitors were tested for their effect on PKA activity and conidial development. A negative correlation was established between PKA inhibition in vitro and fungal development in vivo. Taken collectively, these data suggest that PKA and cAMP play a role in conidial differentiation in this obligate, plant-pathogenic fungus.
Abstract.
Author URL.
Pryce-Jones E, Carver T, Gurr SJ (1999). The roles of cellulase enzymes and mechanical force in host penetration by Erysiphe graminis f.sp. hordei.
Physiological and Molecular Plant Pathology,
55(3), 175-182.
Abstract:
The roles of cellulase enzymes and mechanical force in host penetration by Erysiphe graminis f.sp. hordei
Immunofluorescence microscopy with two monoclonal antibodies raised to two Trichoderma reesei cellobiohydrolases revealed antigen localization at the germ tube tips of Erysiphe graminis f. sp. hordei. Cellobiohydrolase II was present principally at the appressorial germ tube tip and cellobiohydrolase I at the primary germ tube tip. Cell turgor measurements, determined by cytorrhysis and plasmolysis experiments revealed that mature E. graminis appressoria produced a maximum turgor pressure of approximately 2-4 MPa, coincident with host cell penetration from the appressorium. Taken collectively, these results imply that host penetration by E. graminis is effected by a combination of enzyme activity and mechanical force.
Abstract.
1998
Skinner W, Bailey A, Renwick A, Keon J, Gurr S, Hargreaves J (1998). A single amino-acid substitution in the iron-sulphur protein subunit of succinate dehydrogenase determines resistance to carboxin in Mycosphaerella graminicola. Current Genetics, 34(5), 393-398.
Baker SJ, Newton AC, Crabb D, Guy DC, Jefferies RA, Mackerron DKL, Thomas WTB, Gurr SJ (1998). Temporary partial breakdown of mlo-resistance in spring barley by sudden relief of soil water-stress under field conditions: the effects of genetic background and mlo allele.
Plant Pathology,
47(4), 401-410.
Abstract:
Temporary partial breakdown of mlo-resistance in spring barley by sudden relief of soil water-stress under field conditions: the effects of genetic background and mlo allele
This study, carried out under field conditions, assessed the extent to which temporary breakdown of mlo-resistance, following relief of water-stress, was determined by genetic background and mlo allele. Commercial barley cultivars expressing the mlo gene for resistance to powdery mildew (Erysiphe graminis (Blumeria graminis) f. sp. hordei) were tested as well as doubled haploid progeny from spring barley genotypes, a proportion of which were sown in the field in two successive years. Plants were protected from natural rain by a mobile rain shelter and either watered by trickle-irrigation or allowed to dry. Percentage mildew infection resulting from natural inoculum was recorded and the doubled haploid genotypes were classified as resistant, intermediate or susceptible on the basis of their control (watered) treatment scores. In each of the three designated classes, particular genotypes developed infection levels, following relief of water-stress, that were higher than those observed on the well-watered controls. This was found not to be related to the mlo allele as there was no significant difference between the increases observed on resistant plants carrying mlo9 and resistant plants carrying mlo11. Differences in the degree of breakdown of resistance were attributed to genetic background rather than to the specific mlo allele.
Abstract.
1997
(1997). 5589622 Plant parasitic nematode control. Biotechnology Advances, 15(3-4), 664-664.
Gurr PA, Evans K, Dewey FM, Gurr SJ (1997). Otomycosis: the detection of fungi in ears by immunofluorescence microscopy.
Clin Otolaryngol Allied Sci,
22(3), 275-283.
Abstract:
Otomycosis: the detection of fungi in ears by immunofluorescence microscopy.
The procedure currently used to diagnose infection in otitis externa has several limitations: it is slow to culture organisms on growth media, fungal infections are often missed, and extensive laboratory facilities and mycological expertise are required. A rapid, accurate and sensitive assay would greatly improve patient care by initiating appropriate antifungal treatment at the onset of disease. We report the development of a rapid detection assay for otomycosis using fungal-specific monoclonal antibodies to detect fungi in ear swabs by immunofluorescence microscopy. This assay could form the basis of a detection assay for fungal infections of the head and neck.
Abstract.
Author URL.
1996
Stevens C, Titarenko E, Hargreaves JA, Gurr SJ (1996). Defence-related gene activation during an incompatible interaction between Stagonospora (Septoria) nodorum and barley (Hordeum vulgare L.) coleoptile cells.
Plant Mol Biol,
31(4), 741-749.
Abstract:
Defence-related gene activation during an incompatible interaction between Stagonospora (Septoria) nodorum and barley (Hordeum vulgare L.) coleoptile cells.
Two previously unidentified cDNA clones (bsi1 and bpr1-1) were isolated by differential hybridization from a cDNA library of Stagonospora (Septoria) nodorum (Berk) Castellani & E.G. Germano (teleomorph Phaeosphaeria (Leptosphaeria) nodorum (E. Muller) Hedjaroude-challenged barley (Hordeum vulgare L.) coleoptiles. bsi1 encoded a cysteine-rich protein containing 89 amino acids (aa) with a relative molecular mass (M(r)) of 9405. Protein sequence homologies showed that Bsi1 was very similar to an aluminium-induced protein from wheat and indicated that it was related to the Bowman-Birk-type proteinase inhibitors (BB-PIs). The predicted aa sequence of Bsi1 contained an N-terminal secretory signal sequence which implied that the protein was exported. The other clone, bprl-1, which was truncated at the 5' end, encoded a type-1 pathogenesis-related (PR-1) protein. The complete sequence of bpr1-1 was obtained after cloning a barley genomic DNA fragment and was shown to encode a basic protein containing 174 aa with a M(r) of 18 859. The deduced aa sequence of bpr1-1 contained both an N-terminal secretory signal sequence and a charged C-terminal extension. This latter sequence may represent a vacuolar targeting signal. bsil and bpr1-1 and four other defence-related genes (encoding 1,3-beta-glucanase, 3-hydroxy-3-methylglutaryl-coenzyme a (HMG-CoA) reductase, a homologue of a putative wheat peroxidase, and barley leaf-specific thionin), showed increased transcription levels in S. nodorum-challenged coleoptiles, although their pattern of accumulation varied after inoculation (a.i.). The potential role of these induced genes in defence against fungal attack is discussed.
Abstract.
Author URL.
Gurr SJ, Francis S (1996). Plant Pathology, Molecular, a Current Review. In Beaubien M (Ed) Encyclopedia of Molecular Biology, 475-485.
Gurr SJ, McPherson M, Bowles D, Atkinson H (1996). Plant parasitic nematode control.
Gurr PA, Chakraverty A, Callanan V, Gurr SJ (1996). The detection of Mycoplasma pneumoniae in nasal polyps.
Clin Otolaryngol Allied Sci,
21(3), 269-273.
Abstract:
The detection of Mycoplasma pneumoniae in nasal polyps.
The aetiology and microbial flora of nasal polyps is not well understood. No study in the literature has reported an association between the sub-bacterium Mycoplasma pneumoniae and nasal polyps. We have developed an assay method using the Polymerase Chain Reaction (PCR) to amplify a specific region of the M. pneumoniae DNA in extracts of clinical samples using species-specific primers designed to a region of the 16S rRNA. The presence of M. pneumoniae was detected in 13/14 (93%) nasal polyps, in 4/5 (80%) rhinosinusitis mucosal samples but only in 1/7 (14%) of control samples (obstructive turbinates). An epidemic of infections due to M. pneumoniae is expected to occur in 1995. We believe this assay could form the basis of a rapid technique for M. pneumoniae detection. We also propose that the presence of M. pneumoniae may be of importance in the aetiology of nasal polyps.
Abstract.
Author URL.
Francis SA, Dewey FM, Gurr SJ (1996). The role of cutinase in germling development and infection by Erysiphe graminis f.sp. hordei.
Physiological and Molecular Plant Pathology,
49(3), 201-211.
Abstract:
The role of cutinase in germling development and infection by Erysiphe graminis f.sp. hordei
We have investigated the importance of cutinase in the germination of Erysiphe graminis f.sp. hordei conidia, specifically in the induction of appressorial germ tube (AGT) formation and penetration of the host cuticle. When cutin monomers were tooted onto glass microscope slides or plastic coverslips, the percentage of AGT differentiation in germinating conidia dramatically increased. This suggests that cutin monomers act as a signal to trigger AGT development. The esterase inhihitors ebelactone a and ebelactone B inhibited E. graminis cutinase activity in germinated spores in microtitre plate wells. Low concentrations of ebelactones did not affect spore germination anti AGT differentiation on cellulose dialysis membrane, an artificial surface on which germling morphogenesis is normal to the AGT stage. However, AGT formation on ebelactone-treated barley leaves was significantly lower than on cellulose. Inhibition of cutinase by ebelactones may have prevented cutin monomers being released from the cuticle and thus affected germling development on the leaf. Ebelactones applied to leaves also prevented infection of the host and development of mature sporulating colonies. These results suggest that cutinase plays an important role in the pathogenicity of E. graminis and may affect germination as well as cuticular penetration.
Abstract.
1995
Gurr SJ (1995). Molecular Plant Pathology. In Meyers R (Ed) Encyclopedia of Molecular Biology: Fundamentals and Applications, VCH Publishers, 699-703.
1994
Gurr S, Titarenko E, Ogel Z, Stevens C, Carver T, Dewey M, Hargreaves J (1994). Barley-fungal interactions: signals and the environment of the host-pathogen interface. Biochemical Society Symposia, 60, 75-88.
1993
Gurr SJ, Atkinson HJ, McPherson MJ (1993). Feeding site specific promoters WO92. /. 04453.
1992
Gurr SJ, McPherson MJ, Bowles DJ, Atkinson HJ (1992). Anti-potato cyst nematode strategies.
Gurr SJ, Titarenko E, Hargreaves J, Keon J (1992). Defence-related gene expression in barley following infection by Septoria nodorum. In Fritig B (Ed) Mechanisms of Plant Defence Responses, Kluwer, 125-128.
Gurr SJ, McPherson MJ (1992). Gene cloning via the polymerase chain reaction. In Gurr SJ, Bowles DJ, McPherson MJ (Eds.) Molecular Plant Pathology - a Practical Approach, 147-217.
Atkinson HJ, Gurr SJ, McPherson MJ, MacGregor AN, Bowles DJ (1992). Molecular events at nematode-induced feeding sites.
Netherlands Journal of Plant Pathology,
98(2 Supplement), 175-181.
Abstract:
Molecular events at nematode-induced feeding sites
Current control of nematodes is inadequate and this justifies work towards the design of novel bases for plant defence. Our approach for cyst nematodes began by improving understanding of critical events in the establishment of these biotrophic pathogens. The first step involved development of an experimental system for achieving synchronous infection and establishment of cyst-nematodes in roots. Monoclonal antibodies have been raised against these nematodes, their specificity defined and those of particular interest used to define events in the establishment of the animals within plants. A similar approach has been explored for host responses using antibodies raised to plant tissue containing feeding sites. Changes in translatable mRNA populations at the feeding site have been described. © 1992 Koninklijke Nederlandse Planteziektenkundige Vereniging.
Abstract.
Gurr SJ, Harper G, Bowles D, Atkinson H (1992). Nematode-induced gene expression. In Fritig B (Ed) Mechanisms of Plant Defence Responses, Kluwer, 136-138.
Gurr SJ, McPherson M (1992). Nucleic Acid Isolation and Hybridisation techniques. In Gurr SJ, Bowles DJ, McPherson MJ (Eds.) Molecular Plant Pathology ¬- a Practical Approach, Oxford University Press, 109-121.
Gurr SJ, McPherson MJ, Jones K (1992). PCR with highly degenerate. oligonucleotide primers. In McPherson MJ (Ed) PCR: a Practical Approach, Oxford University Press, 1770-1780.
Smallwood MF, Gurr SJ, McPherson MJ, Roberts K, Bowles DJ (1992). The pattern of plant annexin gene expression.
Biochem J,
281 ( Pt 2)(Pt 2), 501-505.
Abstract:
The pattern of plant annexin gene expression.
Peptide sequence data derived from a plant annexin, P34 [Smallwood, Keen & Bowles (1990) Biochem. J. 270, 157-161] was used to design amplimers for PCR. A unique fragment of 95 bp, amplified from tomato (Lycopersicon esculertum) genomic DNA, was used in Northern analyses and demonstrated a differential pattern of expression in vegetative tissues of tomato, potato (Solanum tuberosum) and barley (Hordeum vulgare). The tissue-specific abundance of the annexin transcript was found to correlate closely with abundance of annexin protein as revealed by their partial purification and analysis with antisera specific for annexins isolated from tomato suspension-culture cells.
Abstract.
Author URL.
1991
Gurr SJ, McPherson MJ, Scollan C, Atkinson HJ, Bowles DJ (1991). Gene expression in nematode-infected plant roots.
Mol Gen Genet,
226(3), 361-366.
Abstract:
Gene expression in nematode-infected plant roots.
A major pathogen of potato plants (Solanum tuberosum) is the potato cyst nematode (Globodera spp.), which induces localized redifferentiation of a limited number of host cells to form a specialized feeding-site termed the syncytium. A novel strategy utilizing the polymerase chain reaction (PCR) was employed to construct a cDNA library from dissected potato roots highly enriched in syncytial material. The library was differentially screened with cDNA probes derived from the infected root tissue from a compatible interaction and from healthy root tissue. Characterization of one gene identified by the library screen indicated an expression pattern that correlated with events in the immediate vicinity of the pathogen after syncytial establishment. The strategy for library construction and screening could be applicable to the study of gene expression in any plant-pathogen interaction in which the limited supply of cells at the interface of the two organisms precludes a more traditional approach.
Abstract.
Author URL.
Gurr SJ, Bowles DJ, Hammond-Kosak KE, Atkinson HJ (1991). Local and systemic changes in plant gene expression following root infection by cyst nematodes. In Smith CJ (Ed) Biochemistry and Molecular Biology of Plant Pathogen Interactions, 140-152.
Gurr SJ (1991). PCR Protocols-A Guide to Methods and Applications Edited by M a Innis, D H Gelfand, J J Sninsky and T J White. pp 482. Academic Press, London 1990. $39.95. Biochemistry and Molecular Biology Education, 19(1).
Gurr SJ, McPherson MJ (1991). PCR-directed cDNA library construction. In McPherson MJ, Quirke P, Taylor GR (Eds.) PCR: a Practical Approach, Oxford University Press, 123-145.
1990
Smallwood MF, Gurr SJ, Choudhari U, Bowles DJ (1990). Characterization of plant annexin gene expression.
Biochem Soc Trans,
18(6).
Author URL.
Gurr SJ, Whitehead M, Greaves C, Kinghorn J (1990). Homologous transformation of Cephalosporium acremonium with the nitrate reductase-encoding gene (niaD). Gene, 90(2), 193-198.
Johnstone IL, McCabe PC, Greaves P, Gurr SJ, Cole GE, Brow MA, Unkles SE, Clutterbuck AJ, Kinghorn JR, Innis MA, et al (1990). Isolation and characterisation of the crnA-niiA-niaD gene cluster for nitrate assimilation in Aspergillus nidulans.
Gene,
90(2), 181-192.
Abstract:
Isolation and characterisation of the crnA-niiA-niaD gene cluster for nitrate assimilation in Aspergillus nidulans.
Genomic clones containing the entire crnA-niiA-niaD gene cluster of Aspergillus nidulans have been isolated, and the structures of the niiA and niaD genes have been determined by nucleotide sequence analysis. This gene cluster is required for the assimilation of nitrate in A. nidulans, and the three genes encode a product required for nitrate uptake and the enzymes, nitrite reductase and nitrate reductase, respectively. The putative coding sequences, as deduced by comparison to cDNA clones of both niiA and niaD, are interrupted by multiple small introns, and the two genes are divergently transcribed. Identification and characterization of specific mRNAs involved in nitrate assimilation indicates that only monocistronic transcripts are involved, and that the approximate sizes of these transcripts are 1.6 kb, 3.4 kb and 2.8 kb for crnA, niiA and niaD, respectively. The results also indicate that control of niiA and niaD gene expression is mediated by the levels of mRNA accumulation, in response to the source of nitrogen in the growth medium. Two types of transcripts for niiA were observed.
Abstract.
Author URL.
Gurr SJ, Whitehead M, McCabe A, Ramsden M, Kinghorn JR (1990). Transformation of industrial fungi with homologous & heterologous nitrate reductase genes.
1989
Hawkins AR, Gurr SJ, Montague P, Kinghorn JR (1989). Nucleotide sequence and regulation of expression of the Aspergillus nidulans gdhA gene encoding NADP dependent glutamate dehydrogenase.
Mol Gen Genet,
218(1), 105-111.
Abstract:
Nucleotide sequence and regulation of expression of the Aspergillus nidulans gdhA gene encoding NADP dependent glutamate dehydrogenase.
The nucleotide sequence of the Aspergillus nidulans gdhA gene encoding NADP linked glutamate dehydrogenase has been determined and Northern blot analysis used to study the regulation of expression of this gene. The gdhA gene is 1485 nucleotides long and, by comparison with the corresponding Neurospora crassa am gene, has two putative introns of 53 nucleotides and a protein encoding region of 1380 nucleotides that codes for an inferred protein of 49.63 kDa which shows regions of homology with glutamate dehydrogenase proteins from a range of organisms. mRNA analysis of wild-type mycelium grown under a variety of conditions shows that: (a) the highest levels are seen with glucose as the carbon source with inorganic nitrogen; and (b) no gdhA mRNA is detectable when cells are transferred to amino acids as sole carbon source, closely matching the observed glutamate dehydrogenase activity levels under identical conditions. The results presented strongly suggest that a good carbon source is a prerequisite for transcription, but the molecular mechanism responsible is unclear.
Abstract.
Author URL.
Gurr SJ, Campbell A, Moon R, Duncan J, Kinghorn JR (1989). Protoplast formation and regeneration from sporangia and encysted zoospores of Phytophthora infestans. Physiological and Molecular Plant Pathology, 34(4), 299-307.
Whitehead MP, Unkles SE, Ramsden M, Campbell EI, Gurr SJ, Spence D, van den Hondel C, Contreras R, Kinghorn JR (1989). Transformation of a nitrate reductase deficient mutant of Penicillium chrysogenum with the corresponding Aspergillus niger and A. nidulans niaD genes.
MGG Molecular & General Genetics,
216(2-3), 408-411.
Abstract:
Transformation of a nitrate reductase deficient mutant of Penicillium chrysogenum with the corresponding Aspergillus niger and A. nidulans niaD genes
A heterologous gene mediated transformation system based on niaD, the structural gene encoding nitrate reductase, has been developed for Penicillium chrysogenum. Transformation frequencies of up to 20 transformants per microgram DNA were obtained using the Aspergillus nidulans gene and 9 transformants per microgram using the A. niger gene. Vector constructs carrying the A. nidulans ans-1 sequence and the A. niger niaD gene did not show increased transformation frequencies. Southern blot hybridisation analysis demonstrated that vector sequences had integrated into the recipient genome. The control of heterologous niaD gene expression generally agreed with that found in the wild-type strain, that is, induction by nitrate and repression in the presence of ammonium. © 1989 Springer-Verlag.
Abstract.
1988
Gurr SJ, Kinghorn J (1988). Designation of filamentous fungal genes identified by molecular cloning. Fungal Genetics, 5, 26-28.
1987
Gurr SJ, Unkles S, Kinghorn J (1987). The structure and organisation of nuclear genes of filamentous fungi. In: Gene Structure in Eukaryotic Microbes. In Kinghorn J (Ed) Gene Structure in Eukaryotic Microbes, Oxford: IRL Press, 93-139.
1986
Gurr SJ, Hawkins AR, Drainas C, Kinghorn JR (1986). Isolation and identification of the Aspergillus nidulans gdhA gene encoding NADP-linked glutamate dehydrogenase.
Curr Genet,
10(10), 761-766.
Abstract:
Isolation and identification of the Aspergillus nidulans gdhA gene encoding NADP-linked glutamate dehydrogenase.
The Neurospora crassa am gene was used as a heterologous probe to identify clones from two independently constructed Aspergillus nidulans gene libraries. These clones have a common HindIII 1.85 kb fragment. This A. nidulans nucleotide stretch hybridises to a N. crassa 2.7 kb BamHI fragment of wild type DNA but not to a co-migrating fragment from the DNA of the N. crassa am132 deletion mutant. One A. nidulans clone was shown to complement the N. crasse am132 deletion strain. The N. crassa transformants show low levels (approximately 5%) of heterologous glutamate dehydrogenase activity. The A. nidulans gdhA gene was found to locate in N. crassa at both the "homologous" (i.e. am) site as well as non-homologous sites. Partial nucleotide analysis of the fragment has revealed the 5' end of the locus and considerable homology with the N. crassa am gene. We concluded that we have cloned the A. nidulans gdhA gene.
Abstract.
Author URL.
Gurr SJ, Kinghorn JR (1986). The nucleotide sequence of Aspergillus nidulans gdhA gene. Heredity, 57, 136-139.
