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Srivastava V, Patra K, Pai H, Aguilar-Pontes MV, Berasategui A, Kamble A, Di Pietro A, Redkar A. Molecular Dialogue During Host Manipulation by the Vascular Wilt Fungus Fusarium oxysporum. ANNUAL REVIEW OF PHYTOPATHOLOGY 2024; 62:97-126. [PMID: 38885471 DOI: 10.1146/annurev-phyto-021722-034823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2024]
Abstract
Vascular wilt fungi are a group of hemibiotrophic phytopathogens that infect diverse crop plants. These pathogens have adapted to thrive in the nutrient-deprived niche of the plant xylem. Identification and functional characterization of effectors and their role in the establishment of compatibility across multiple hosts, suppression of plant defense, host reprogramming, and interaction with surrounding microbes have been studied mainly in model vascular wilt pathogens Fusarium oxysporum and Verticillium dahliae. Comparative analysis of genomes from fungal isolates has accelerated our understanding of genome compartmentalization and its role in effector evolution. Also, advances in recent years have shed light on the cross talk of root-infecting fungi across multiple scales from the cellular to the ecosystem level, covering their interaction with the plant microbiome as well as their interkingdom signaling. This review elaborates on our current understanding of the cross talk between vascular wilt fungi and the host plant, which eventually leads to a specialized lifestyle in the xylem. We particularly focus on recent findings in F. oxysporum, including multihost associations, and how they have contributed to understanding the biology of fungal adaptation to the xylem. In addition, we discuss emerging research areas and highlight open questions and future challenges.
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Affiliation(s)
- Vidha Srivastava
- National Centre for Biological Sciences, Tata Institute of Fundamental Research (NCBS-TIFR), Bengaluru, India;
| | - Kuntal Patra
- National Centre for Biological Sciences, Tata Institute of Fundamental Research (NCBS-TIFR), Bengaluru, India;
| | - Hsuan Pai
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
| | | | - Aileen Berasategui
- Amsterdam Institute for Life and Environment, Vrije Universiteit, Amsterdam, The Netherlands
| | - Avinash Kamble
- Department of Botany, Savitribai Phule Pune University, Pune, India
| | | | - Amey Redkar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research (NCBS-TIFR), Bengaluru, India;
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2
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Plett JM, Plett KL. Leveraging genomics to understand the broader role of fungal small secreted proteins in niche colonization and nutrition. ISME COMMUNICATIONS 2022; 2:49. [PMID: 37938664 PMCID: PMC9723739 DOI: 10.1038/s43705-022-00139-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 05/24/2022] [Accepted: 06/08/2022] [Indexed: 08/09/2023]
Abstract
The last few years have seen significant advances in the breadth of fungi for which we have genomic resources and our understanding of the biological mechanisms evolved to enable fungi to interact with their environment and other organisms. One field of research that has seen a paradigm shift in our understanding concerns the role of fungal small secreted proteins (SSPs) classified as effectors. Classically thought to be a class of proteins utilized by pathogenic microbes to manipulate host physiology in support of colonization, comparative genomic studies have demonstrated that mutualistic fungi and fungi not associated with a living host (i.e., saprotrophic fungi) also encode inducible effector and candidate effector gene sequences. In this review, we discuss the latest advances in understanding how fungi utilize these secreted proteins to colonize a particular niche and affect nutrition and nutrient cycles. Recent studies show that candidate effector SSPs in fungi may have just as significant a role in modulating hyphosphere microbiomes and in orchestrating fungal growth as they do in supporting colonization of a living host. We conclude with suggestions on how comparative genomics may direct future studies seeking to characterize and differentiate effector from other more generalized functions of these enigmatic secreted proteins across all fungal lifestyles.
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Affiliation(s)
- Jonathan M Plett
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
| | - Krista L Plett
- Elizabeth Macarthur Agricultural Institute, NSW Department of Primary Industries, Menangle, NSW, 2568, Australia
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3
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Ochieno DMW. Soil Sterilization Eliminates Beneficial Microbes That Provide Natural Pest Suppression Ecosystem Services Against Radopholus similis and Fusarium Oxysporum V5w2 in the Endosphere and Rhizosphere of Tissue Culture Banana Plants. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2022. [DOI: 10.3389/fsufs.2022.688194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Endosphere and rhizosphere microbes offer plant growth promotion and pest suppression ecosystem services in banana-based agroecosystems. Interest has been growing towards the use of such beneficial microbes in protecting vulnerable tissue culture banana plants against pathogens such as Radopholus similis and Fusarium oxysporum. A screenhouse experiment with potted tissue culture banana plants was conducted using sterile and non-sterile soil to investigate the effect of soil biota on R. similis and F. oxysporum strain V5w2. Plants grown in non-sterile soil had lower damage and R. similis density in roots and rhizosphere, while most plant growth-related parameters including root freshweight, shoot freshweight, total freshweight, plant height, and leaf size were larger compared to those from sterile soil. Shoot dryweight and Mg content were higher in plants from sterile soil, while their leaves developed discolored margins. R. similis-inoculated plants in sterile soil were smaller, had more dead roots, higher nematode density, and produced fewer and smaller leaves, than those from non-sterile soil. For all plant growth-related parameters, nematode density and root damage, no differences were recorded between controls and F. oxysporum V5w2-inoculated plants; and no differences between those inoculated with R. similis only and the ones co-inoculated with the nematode and F. oxysporum V5w2. Banana roots inoculated with F. oxysporum V5w2 were lighter in color than those without the fungus. Independent or combined inoculation of banana plants with F. oxysporum V5w2 and R. similis resulted in lower optical density of root extracts. In vitro assays indicated the presence of Fusarium spp. and other root endophytic microbes that interacted antagonistically with the inoculated strain of F. oxysporum V5w2. It is concluded that, soil sterilization eliminates beneficial microbes that provide natural pest suppression ecosystem services against R. similis and F. oxysporum in the endosphere and rhizosphere of tissue culture banana plants. I recommend the integration of microbiome conservation into tissue culture technology through the proposed “Tissue Culture Microbiome Conservation Technology.”
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Havenga M, Wingfield BD, Wingfield MJ, Dreyer LL, Roets F, Aylward J. Genetic response to nitrogen starvation in the aggressive Eucalyptus foliar pathogen Teratosphaeria destructans. Curr Genet 2021; 67:981-990. [PMID: 34432124 DOI: 10.1007/s00294-021-01208-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 07/20/2021] [Accepted: 08/21/2021] [Indexed: 12/13/2022]
Abstract
Teratosphaeria destructans is one of the most aggressive foliar pathogens of Eucalyptus. The biological factors underpinning T. destructans infections, which include shoot and leaf blight on young trees, have never been interrogated. Thus, the means by which the pathogen modifies its host environment to overcome host defences remain unknown. By applying transcriptome sequencing, the aim of this study was to compare gene expression in a South African isolate of T. destructans grown on nitrogen-deficient and complete media. This made it possible to identify upregulated genes in a nitrogen-starved environment, often linked to the pathogenicity of the fungus. The results support the hypothesis that nitrogen starvation in T. destructans likely mirrors an in planta genetic response. This is because 45% of genes that were highly upregulated under nitrogen starvation have previously been reported to be associated with infection in other pathogen systems. These included several CAZymes, fungal effector proteins, peptidases, kinases, toxins, lipases and proteins associated with detoxification of toxic compounds. Twenty-five secondary metabolites were identified and expressed in both nitrogen-deficient and complete conditions. Additionally, the most highly expressed genes in both growth conditions had pathogenicity-related functions. This study highlights the large number of expressed genes associated with pathogenicity and overcoming plant defences. As such, the generated baseline knowledge regarding pathogenicity and aggressiveness in T. destructans is a valuable reference for future in planta work.
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Affiliation(s)
- Minette Havenga
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa. .,Department of Conservation Ecology and Entomology, Stellenbosch University, Stellenbosch, South Africa.
| | - Brenda D Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Michael J Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Léanne L Dreyer
- Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa
| | - Francois Roets
- Department of Conservation Ecology and Entomology, Stellenbosch University, Stellenbosch, South Africa
| | - Janneke Aylward
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa.,Department of Conservation Ecology and Entomology, Stellenbosch University, Stellenbosch, South Africa
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Tang C, Li W, Klosterman SJ, Wang Y. Transcriptome Variations in Verticillium dahliae in Response to Two Different Inorganic Nitrogen Sources. Front Microbiol 2021; 12:712701. [PMID: 34394062 PMCID: PMC8355529 DOI: 10.3389/fmicb.2021.712701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 07/01/2021] [Indexed: 11/16/2022] Open
Abstract
The fungus Verticillium dahliae causes vascular wilt disease on hundreds of plant species. The main focus of the research to control this fungus has been aimed at infection processes such as penetration peg formation and effector secretion, but the ability of the fungus to acquire and utilize nutrients are often overlooked and may hold additional potential to formulate new disease control approaches. Little is known about the molecular mechanisms of nitrogen acquisition and assimilation processes in V. dahliae. In this present study, RNA sequencing and gene expression analysis were used to examine differentially expressed genes in response to the different nitrogen sources, nitrate and ammonium, in V. dahliae. A total of 3244 and 2528 differentially expressed genes were identified in response to nitrate and ammonium treatments, respectively. The data indicated nitrate metabolism requires additional energy input while ammonium metabolism is accompanied by reductions in particular cellular processes. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses of DEGs during nitrate metabolism revealed that many of the genes encoded those involved in protein biosynthetic and metabolic processes, especially ribosome and RNA polymerase biosynthesis, but also other processes including transport and organonitrogen compound metabolism. Analysis of DEGs in the ammonium treatment indicated that cell cycle, oxidoreductase, and certain metabolic activities were reduced. In addition, DEGs participating in the utilization of both nitrate and ammonium were related to L-serine biosynthesis, energy-dependent multidrug efflux pump activity, and glycerol transport. We further showed that the mutants of three differentially expressed transcription factors (VdMcm1, VdHapX, and VDAG_08640) exhibited abnormal phenotypes under nitrate and ammonium treatment compared with the wild type strain. Deletion of VdMcm1 displayed slower growth when utilizing both nitrogen sources, while deletion of VdHapX and VDAG_08640 only affected nitrate metabolism, inferring that nitrogen assimilation required regulation of bZIP transcription factor family and participation of cell cycle. Taken together, our findings illustrate the convergent and distinctive regulatory mechanisms between preferred (ammonium) and alternative nitrogen (nitrate) metabolism at the transcriptome level, leading to better understanding of inorganic nitrogen metabolism in V. dahliae.
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Affiliation(s)
- Chen Tang
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China
| | - Wenwen Li
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China
| | - Steven J Klosterman
- Agricultural Research Service, United States Department of Agriculture, Salinas, CA, United States
| | - Yonglin Wang
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China
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Hu W, Yang B, He Z, Li G. Magnesium may be a key nutrient mechanism related to Fusarium wilt resistance: a new banana cultivar (Zhongjiao No. 9). PeerJ 2021; 9:e11141. [PMID: 33868816 PMCID: PMC8029668 DOI: 10.7717/peerj.11141] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 03/01/2021] [Indexed: 11/20/2022] Open
Abstract
Zhongjiao No. 9 (Musa spp.), a new Fusarium wilt-resistant banana cultivar, has shown considerable promise in the field. However, the growth, nutrient budgets, and key nutrient mechanisms related to Fusarium wilt resistance have not been explicitly examined. Here, the plant growth, yield, fruit quality, and nutrient budgets of Zhongjiao No. 9 were investigated. The results showed that Zhongjiao No. 9 has a large biomass with a high yield (54.65 t ha−1). The concentrations of N, P, K, Ca, Mg, Mn, B, and Mo were mainly high in the leaves and bunches of mother plants as well as in the leaves and pseudostems of daughter plants, while Cu and Fe were enriched in the roots of both mother plants and daughter plants. Linear discriminant analysis revealed that K, Ca, and Fe were important for plant growth in both the mother plants and daughter plants; S, Zn, and Mn were important for the mother plants, and N, P, and B for were important for the daughter plants. The nutrient uptake ratio of N:P:K:Ca:Mg:S was 1:0.13:3.86:0.68:0.40:0.07. Compared with local cultivars, there was a higher Mg concentration in pseudostems and a higher Mg uptake ratio were observed in Zhongjiao No. 9. Together, our results provide insight into the importance of Mg accumulation in relation to Fusarium wilt resistance, and we provide information on nutrient demands and fertilization application.
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Affiliation(s)
- Weifang Hu
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Baomei Yang
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Zhaohuan He
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Guoliang Li
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Guangzhou, China
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König A, Müller R, Mogavero S, Hube B. Fungal factors involved in host immune evasion, modulation and exploitation during infection. Cell Microbiol 2020; 23:e13272. [PMID: 32978997 DOI: 10.1111/cmi.13272] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/20/2020] [Accepted: 07/26/2020] [Indexed: 01/09/2023]
Abstract
Human and plant pathogenic fungi have a major impact on public health and agriculture. Although these fungi infect very diverse hosts and are often highly adapted to specific host niches, they share surprisingly similar mechanisms that mediate immune evasion, modulation of distinct host targets and exploitation of host nutrients, highlighting that successful strategies have evolved independently among diverse fungal pathogens. These attributes are facilitated by an arsenal of fungal factors. However, not a single molecule, but rather the combined effects of several factors enable these pathogens to establish infection. In this review, we discuss the principles of human and plant fungal pathogenicity mechanisms and discuss recent discoveries made in this field.
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Affiliation(s)
- Annika König
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute, Jena, Germany
| | - Rita Müller
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute, Jena, Germany
| | - Selene Mogavero
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute, Jena, Germany
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute, Jena, Germany.,Center for Sepsis Control and Care, University Hospital Jena, Jena, Germany.,Institute of Microbiology, Friedrich Schiller University, Jena, Germany
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8
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Nugent B, Ali SS, Mullins E, Doohan FM. A Major Facilitator Superfamily Peptide Transporter From Fusarium oxysporum Influences Bioethanol Production From Lignocellulosic Material. Front Microbiol 2019; 10:295. [PMID: 30863378 PMCID: PMC6399157 DOI: 10.3389/fmicb.2019.00295] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 02/04/2019] [Indexed: 11/13/2022] Open
Abstract
Fusarium oxysporum is a leading microbial agent in the emerging consolidated bioprocessing (CBP) industry owing to its capability to infiltrate the plant's lignin barrier and degrade complex carbohydrates to value-added chemicals such as bioethanol in a single step. Membrane transport of nutrients is a key factor in successful microbial colonization of host tissue. This study assessed the impact of a peptide transporter on F. oxysporum's ability to convert lignocellulosic straw to ethanol. We characterized a novel F. oxysporum peptide transporter (FoPTR2) of the dipeptide/tripeptide transporter (PTR) class. FoPTR2 represents a novel transporter with high homology to the Trichoderma sp. peptide transporters ThPTR2 and TrEST-AO793. Its expression level was highly activated in nitrogen-poor environments, which is a characteristic of PTR class peptide transporters. Overexpression and post-translational gene silencing of the FoPTR2 in F. oxysporum affected the peptide transport capacity and ethanol yielded from a both a wheat straw/bran mix and glucose. Thus, we conclude that it FoPTR2 plays a role in the nutrient acquisition system of F. oxysporum which serves to not only enhance fungal fitness but also CBP efficacy.
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Affiliation(s)
- Brian Nugent
- Molecular Plant-Microbe Interactions Laboratory, School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
| | - Shahin S. Ali
- Molecular Plant-Microbe Interactions Laboratory, School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
| | - Ewen Mullins
- Department of Crop Science, Teagasc Research Centre, Carlow, Ireland
| | - Fiona M. Doohan
- Molecular Plant-Microbe Interactions Laboratory, School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
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9
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Lin Z, Wang J, Bao Y, Guo Q, Powell CA, Xu S, Chen B, Zhang M. Deciphering the transcriptomic response of Fusarium verticillioides in relation to nitrogen availability and the development of sugarcane pokkah boeng disease. Sci Rep 2016; 6:29692. [PMID: 27434999 PMCID: PMC4951700 DOI: 10.1038/srep29692] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 06/23/2016] [Indexed: 11/24/2022] Open
Abstract
Pokkah boeng, caused by Fusarium verticillioides, is a serious disease in sugarcane industry. The disease severity is related to the sugarcane genotype as well as environmental considerations, such as nitrogen application. The impact of the nitrogen source (ammonium sulfate, urea, or sodium nitrate) on sugarcane pokkah boeng disease and its pathogen was investigated in planta and fungal growth and sporulation production was measured in vitro. The results showed that ammonium and nitrate were beneficial to fungal mycelium growth, cell densities, and sporulation, which enhanced the disease symptoms of sugarcane pokkah boeng compared to urea fertilization. A total of 1,779 transcripts out of 13,999 annotated genes identified from global transcriptomic analysis were differentially expressed in F. verticillioides CNO-1 grown in the different sources of nitrogen. These were found to be involved in nitrogen metabolism, transport, and assimilation. Many of these genes were also associated with pathogenicity based on the PHI-base database. Several transcription factors were found to be associated with specific biological processes related to nitrogen utilization. Our results further demonstrated that nitrogen availability might play an important role in disease development by increasing fungal cell growth as well as influencing the expression of genes required for successful pathogenesis.
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Affiliation(s)
- Zhenyue Lin
- State Key Lab for Conservation and Utilization of Subtropical Agric-Biological Resources, Guangxi University, Nanning, 530005, China
| | - Jihua Wang
- State Key Lab for Conservation and Utilization of Subtropical Agric-Biological Resources, Guangxi University, Nanning, 530005, China
| | - Yixue Bao
- State Key Lab for Conservation and Utilization of Subtropical Agric-Biological Resources, Guangxi University, Nanning, 530005, China
| | - Qiang Guo
- State Key Lab for Conservation and Utilization of Subtropical Agric-Biological Resources, Guangxi University, Nanning, 530005, China
| | - Charles A. Powell
- Indian River Research and Education Center, IFAS, University of Florida, Fort Pierce, FL 34945, USA
| | - Shiqiang Xu
- State Key Lab for Conservation and Utilization of Subtropical Agric-Biological Resources, Guangxi University, Nanning, 530005, China
| | - Baoshan Chen
- State Key Lab for Conservation and Utilization of Subtropical Agric-Biological Resources, Guangxi University, Nanning, 530005, China
| | - Muqing Zhang
- State Key Lab for Conservation and Utilization of Subtropical Agric-Biological Resources, Guangxi University, Nanning, 530005, China
- Indian River Research and Education Center, IFAS, University of Florida, Fort Pierce, FL 34945, USA
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10
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Liu T, Wang Y, Ma B, Hou J, Jin Y, Zhang Y, Ke X, Tai L, Zuo Y, Dey K. Clg2p interacts with Clf and ClUrase to regulate appressorium formation, pathogenicity and conidial morphology in Curvularia lunata. Sci Rep 2016; 6:24047. [PMID: 27041392 PMCID: PMC4819193 DOI: 10.1038/srep24047] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 03/18/2016] [Indexed: 01/19/2023] Open
Abstract
Ras is a small GTPase that regulates numerous processes in the cellular development and morphogenesis of many organisms. In this study, we identified and functionally characterized the Clg2p gene of Curvularia lunata, which is homologous with the Ras protein. The Clg2p deletion mutant (ΔClg2p) had altered appressorium formation and conidial morphology and produced fewer, smaller lesions compared with the wild-type strain. When a dominant Clg2p allele was introduced into the mutant, all of these defective phenotypes were completely restored. To further understand the regulation of Clg2p in appressorium formation and conidial morphology, and its role in pathogenicity, seven Clg2p-interacting proteins were screened using a yeast two-hybrid assay. Two of these proteins, Clf, a homologue of Mst11, which corresponds to MAP kinase kinase kinase in Magnaporthe oryzae, and urate oxidase (designated ClUrase) were functionally characterized. Clg2p specifically interacted with Clf through its RA domain to regulate appressorium formation and pathogenicity, whereas the Clg2p-ClUrase interaction regulated conidial morphology without affecting fungal pathogenicity. This report is the first to elucidate the regulatory mechanism of the key Ras protein Clg2p in C. lunata.
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Affiliation(s)
- Tong Liu
- Institute of Plant Pathology and Applied Microbiology, School of Agronomy, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, 163319, P. R. China.,State Key Laboratory of Crop Stress Biology in Arid Regions, Northwest A &F University, Yangling, Shanxi, 712100, P. R. China
| | - Yuying Wang
- Institute of Plant Pathology and Applied Microbiology, School of Agronomy, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, 163319, P. R. China
| | - Bingchen Ma
- Institute of Plant Pathology and Applied Microbiology, School of Agronomy, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, 163319, P. R. China
| | - Jumei Hou
- Institute of Plant Pathology and Applied Microbiology, School of Agronomy, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, 163319, P. R. China
| | - Yazhong Jin
- Institute of Plant Pathology and Applied Microbiology, School of Agronomy, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, 163319, P. R. China
| | - Youli Zhang
- Institute of Plant Pathology and Applied Microbiology, School of Agronomy, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, 163319, P. R. China
| | - Xiwang Ke
- National Coarse Cereals Engineering Research Center, Daqing, Heilongjiang, 163319, P. R. China
| | - Lianmei Tai
- Institute of Plant Pathology and Applied Microbiology, School of Agronomy, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, 163319, P. R. China
| | - Yuhu Zuo
- Institute of Plant Pathology and Applied Microbiology, School of Agronomy, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, 163319, P. R. China
| | - Kishore Dey
- Department of Plant and Environmental Protection Sciences, University of Hawaii at Manoa, 3190 Maile Way, Honolulu, HI, 96822, USA
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11
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Wang R, Zhang M, Liu H, Xu J, Yu J, He F, Zhang X, Dong S, Dou D. PsAAT3, an oomycete-specific aspartate aminotransferase, is required for full pathogenicity of the oomycete pathogen Phytophthora sojae. Fungal Biol 2016; 120:620-630. [PMID: 27020161 DOI: 10.1016/j.funbio.2016.01.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 01/02/2016] [Accepted: 01/06/2016] [Indexed: 12/29/2022]
Abstract
Pathogen nutrient acquisition and metabolism are critical for successful infection and colonization. However, the nutrient requirements and metabolic pathways related to pathogenesis in oomycete pathogens are unknown. In this study, we bioinformatically identified Phytophthora sojae aspartate aminotransferases (AATs), which are key enzymes that coordinate carbon and nitrogen metabolism. We demonstrated that P. sojae encodes more AATs than the analysed fungi. Some of the AATs contained additional prephenate dehydratase and/or prephenate dehydrogenase domains in their N-termini, which are unique to oomycetes. Silencing of PsAAT3, an infection-inducible expression gene, reduced P. sojae pathogenicity on soybean plants and affected the growth under N-starving condition, suggesting that PsAAT3 is involved in pathogen pathogenicity and nitrogen utilisation during infection. Our results suggest that P. sojae and other oomycete pathogens may have distinct amino acid metabolism pathways and that PsAAT3 is important for its full pathogenicity.
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Affiliation(s)
- Rongbo Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Meixiang Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Hong Liu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Jing Xu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Jia Yu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Feng He
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Xiong Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Suomeng Dong
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Daolong Dou
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.
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12
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Cissé OH, Pagni M, Hauser PM. Comparative genomics suggests that the human pathogenic fungus Pneumocystis jirovecii acquired obligate biotrophy through gene loss. Genome Biol Evol 2014; 6:1938-48. [PMID: 25062922 PMCID: PMC4159005 DOI: 10.1093/gbe/evu155] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Pneumocystis jirovecii is a fungal parasite that colonizes specifically humans and turns into an opportunistic pathogen in immunodeficient individuals. The fungus is able to reproduce extracellularly in host lungs without eliciting massive cellular death. The molecular mechanisms that govern this process are poorly understood, in part because of the lack of an in vitro culture system for Pneumocystis spp. In this study, we explored the origin and evolution of the putative biotrophy of P. jirovecii through comparative genomics and reconstruction of ancestral gene repertoires. We used the maximum parsimony method and genomes of related fungi of the Taphrinomycotina subphylum. Our results suggest that the last common ancestor of Pneumocystis spp. lost 2,324 genes in relation to the acquisition of obligate biotrophy. These losses may result from neutral drift and affect the biosyntheses of amino acids and thiamine, the assimilation of inorganic nitrogen and sulfur, and the catabolism of purines. In addition, P. jirovecii shows a reduced panel of lytic proteases and has lost the RNA interference machinery, which might contribute to its genome plasticity. Together with other characteristics, that is, a sex life cycle within the host, the absence of massive destruction of host cells, difficult culturing, and the lack of virulence factors, these gene losses constitute a unique combination of characteristics which are hallmarks of both obligate biotrophs and animal parasites. These findings suggest that Pneumocystis spp. should be considered as the first described obligate biotrophs of animals, whose evolution has been marked by gene losses.
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Affiliation(s)
- Ousmane H Cissé
- Institute of Microbiology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, SwitzerlandVital-IT Group, SIB Swiss Institute of Bioinformatics, Lausanne, SwitzerlandPresent address: Department of Plant Pathology & Microbiology and Institute for Integrative Genome Biology, University of California, Riverside, CA
| | - Marco Pagni
- Vital-IT Group, SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Philippe M Hauser
- Institute of Microbiology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Switzerland
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Lanver D, Berndt P, Tollot M, Naik V, Vranes M, Warmann T, Münch K, Rössel N, Kahmann R. Plant surface cues prime Ustilago maydis for biotrophic development. PLoS Pathog 2014; 10:e1004272. [PMID: 25033195 PMCID: PMC4102580 DOI: 10.1371/journal.ppat.1004272] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 06/12/2014] [Indexed: 11/19/2022] Open
Abstract
Infection-related development of phytopathogenic fungi is initiated by sensing and responding to plant surface cues. This response can result in the formation of specialized infection structures, so-called appressoria. To unravel the program inducing filaments and appressoria in the biotrophic smut fungus Ustilago maydis, we exposed cells to a hydrophobic surface and the cutin monomer 16-hydroxy hexadecanoic acid. Genome-wide transcriptional profiling at the pre-penetration stage documented dramatic transcriptional changes in almost 20% of the genes. Comparisons with the U. maydis sho1 msb2 double mutant, lacking two putative sensors for plant surface cues, revealed that these plasma membrane receptors regulate a small subset of the surface cue-induced genes comprising mainly secreted proteins including potential plant cell wall degrading enzymes. Targeted gene deletion analysis ascribed a role to up-regulated GH51 and GH62 arabinofuranosidases during plant penetration. Among the sho1/msb2-dependently expressed genes were several secreted effectors that are essential for virulence. Our data also demonstrate specific effects on two transcription factors that redirect the transcriptional regulatory network towards appressorium formation and plant penetration. This shows that plant surface cues prime U. maydis for biotrophic development. A basic requirement for pathogens to infect their hosts and to cause disease is to detect that they are in contact with the host surface. Plant pathogenic fungi typically respond to leaf surface contact with the development of specialized infection structures enabling the fungus to penetrate the leaf cuticle and to enter the plant tissue. In this study we analyzed the response of the corn smut fungus Ustilago maydis to two plant surface cues, such as hydrophobic surface and cutin monomers. Based on genome-wide gene expression analysis we found that these cues trigger the production of secreted plant cell wall degrading enzymes helping the fungus to penetrate the plant surface. In addition, genes were activated that code for a group of secreted proteins, so-called effectors, that affect virulence after penetration. These results demonstrate that plant surface cues trigger fungal penetration of the plant surface and also prime the fungus for later development inside plant tissue. These specific responses required two cell surface proteins that likely function as plant surface sensors.
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Affiliation(s)
- Daniel Lanver
- Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Marburg, Germany
| | - Patrick Berndt
- Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Marburg, Germany
| | - Marie Tollot
- Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Marburg, Germany
| | - Vikram Naik
- Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Marburg, Germany
| | - Miroslav Vranes
- Karlsruhe Institute of Technology (KIT), Institute for Applied Biosciences, Department of Genetics, Karlsruhe, Germany
| | - Tobias Warmann
- Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Marburg, Germany
| | - Karin Münch
- Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Marburg, Germany
| | - Nicole Rössel
- Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Marburg, Germany
| | - Regine Kahmann
- Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Marburg, Germany
- * E-mail:
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Progress on nitrogen regulation gene expression of plant pathogenic fungi under nitrogen starvation. YI CHUAN = HEREDITAS 2012; 34:848-56. [DOI: 10.3724/sp.j.1005.2012.00848] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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15
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Huang X, Chen X, Coram T, Wang M, Kang Z. Gene expression profiling of Puccinia striiformis f. sp. tritici during development reveals a highly dynamic transcriptome. J Genet Genomics 2011; 38:357-71. [PMID: 21867962 DOI: 10.1016/j.jgg.2011.07.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 07/12/2011] [Accepted: 07/15/2011] [Indexed: 12/27/2022]
Abstract
Puccinia striiformis f. sp. tritici (Pst) causes stripe rust, one of the most important diseases of wheat worldwide. cDNA libraries had been constructed from urediniospores, germinated urediniospores and haustoria. However, little is known about the expression patterns of the genes related to the infection process and sporulation of the pathogen. In this study, a custom oligonucleotide microarray was constructed using sequences of 442 gene transcripts selected from Pst cDNA libraries. The expression patterns of the genes were determined by hybridizing the microarray with cDNA from Pst in vitro and Pst-infected wheat leaves. The time course study identified 55 transcripts that were differentially expressed during the infection process in a compatible interaction. They were identified to have functions related to the following biological processes, including carbohydrate and lipid metabolism, energy, cell signaling, protein synthesis, cell structure and division. In an incompatible interaction, 17 transcripts of the pathogen were differentially expressed in resistant wheat leaves inoculated with an avirulent Pst race, ten of which had similar expression patterns to those in the compatible interaction. Several candidates for pathogenicity and virulence/avirulence related genes were also identified. The results of quantitative real-time PCR validated the expression patterns of some selected genes. The study demonstrates that the custom oligonucleotide microarray technology is useful to determine the expression patterns of the pathogen genes involved in different types of the host-pathogen interactions and stages of development.
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Affiliation(s)
- Xueling Huang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, PR China
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16
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Eaton CJ, Cox MP, Ambrose B, Becker M, Hesse U, Schardl CL, Scott B. Disruption of signaling in a fungal-grass symbiosis leads to pathogenesis. PLANT PHYSIOLOGY 2010; 153:1780-94. [PMID: 20519633 PMCID: PMC2923905 DOI: 10.1104/pp.110.158451] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Accepted: 05/31/2010] [Indexed: 05/02/2023]
Abstract
Symbiotic associations between plants and fungi are a dominant feature of many terrestrial ecosystems, yet relatively little is known about the signaling, and associated transcriptome profiles, that define the symbiotic metabolic state. Using the Epichloë festucae-perennial ryegrass (Lolium perenne) association as a model symbiotic experimental system, we show an essential role for the fungal stress-activated mitogen-activated protein kinase (sakA) in the establishment and maintenance of this mutualistic interaction. Deletion of sakA switches the fungal interaction with the host from mutualistic to pathogenic. Infected plants exhibit loss of apical dominance, premature senescence, and dramatic changes in development, including the formation of bulb-like structures at the base of tillers that lack anthocyanin pigmentation. A comparison of the transcriptome of wild-type and sakA associations using high-throughput mRNA sequencing reveals dramatic changes in fungal gene expression consistent with the transition from restricted to proliferative growth, including a down-regulation of several clusters of secondary metabolite genes and up-regulation of a large set of genes that encode hydrolytic enzymes and transporters. Analysis of the plant transcriptome reveals up-regulation of host genes involved in pathogen defense and transposon activation as well as dramatic changes in anthocyanin and hormone biosynthetic/responsive gene expression. These results highlight the fine balance between mutualism and antagonism in a plant-fungal interaction and the power of deep mRNA sequencing to identify candidate sets of genes underlying the symbiosis.
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Affiliation(s)
| | | | | | | | | | | | - Barry Scott
- Institute of Molecular BioSciences (C.J.E., M.P.C., B.A., M.B., B.S.), Bio-Protection Research Centre (C.J.E., M.P.C., B.S.), and Allan Wilson Centre for Molecular Ecology and Evolution (M.P.C., M.B.), Massey University, Palmerston North, 4442, New Zealand; Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546 (U.H., C.L.S.)
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Pandolfi V, Jorge EC, Melo CMR, Albuquerque ACS, Carrer H. Gene expression profile of the plant pathogen Fusarium graminearum under the antagonistic effect of Pantoea agglomerans. GENETICS AND MOLECULAR RESEARCH 2010; 9:1298-311. [PMID: 20623455 DOI: 10.4238/vol9-3gmr828] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The pathogenic fungus Fusarium graminearum is an ongoing threat to agriculture, causing losses in grain yield and quality in diverse crops. Substantial progress has been made in the identification of genes involved in the suppression of phytopathogens by antagonistic microorganisms; however, limited information regarding responses of plant pathogens to these biocontrol agents is available. Gene expression analysis was used to identify differentially expressed transcripts of the fungal plant pathogen F. graminearum under antagonistic effect of the bacterium Pantoea agglomerans. A macroarray was constructed, using 1014 transcripts from an F. graminearum cDNA library. Probes consisted of the cDNA of F. graminearum grown in the presence and in the absence of P. agglomerans. Twenty-nine genes were either up (19) or down (10) regulated during interaction with the antagonist bacterium. Genes encoding proteins associated with fungal defense and/or virulence or with nutritional and oxidative stress responses were induced. The repressed genes coded for a zinc finger protein associated with cell division, proteins containing cellular signaling domains, respiratory chain proteins, and chaperone-type proteins. These data give molecular and biochemical evidence of response of F. graminearum to an antagonist and could help develop effective biocontrol procedures for pathogenic plant fungi.
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Affiliation(s)
- V Pandolfi
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, SP, Brasil.
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18
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López-Berges MS, Rispail N, Prados-Rosales RC, Di Pietro A. A nitrogen response pathway regulates virulence functions in Fusarium oxysporum via the protein kinase TOR and the bZIP protein MeaB. THE PLANT CELL 2010; 22:2459-75. [PMID: 20639450 PMCID: PMC2929112 DOI: 10.1105/tpc.110.075937] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Revised: 06/03/2010] [Accepted: 06/22/2010] [Indexed: 05/19/2023]
Abstract
During infection, fungal pathogens activate virulence mechanisms, such as host adhesion, penetration and invasive growth. In the vascular wilt fungus Fusarium oxysporum, the mitogen-activated protein kinase Fmk1 is required for plant infection and controls processes such as cellophane penetration, vegetative hyphal fusion, or root adhesion. Here, we show that these virulence-related functions are repressed by the preferred nitrogen source ammonium and restored by treatment with l-methionine sulfoximine or rapamycin, two specific inhibitors of Gln synthetase and the protein kinase TOR, respectively. Deletion of the bZIP protein MeaB also resulted in nitrogen source-independent activation of virulence mechanisms. Activation of these functions did not require the global nitrogen regulator AreA, suggesting that MeaB-mediated repression of virulence functions does not act through inhibition of AreA. Tomato plants (Solanum lycopersicum) supplied with ammonium rather than nitrate showed a significant reduction in vascular wilt symptoms when infected with the wild type but not with the DeltameaB strain. Nitrogen source also affected invasive growth in the rice blast fungus Magnaporthe oryzae and the wheat head blight pathogen Fusarium graminearum. We propose that a conserved nitrogen-responsive pathway might operate via TOR and MeaB to control virulence in plant pathogenic fungi.
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Affiliation(s)
| | | | | | - Antonio Di Pietro
- Departamento de Genética, Universidad de Córdoba, Campus de Rabanales, Edificio Gregor Mendel, 14071 Córdoba, Spain
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Horst RJ, Doehlemann G, Wahl R, Hofmann J, Schmiedl A, Kahmann R, Kämper J, Sonnewald U, Voll LM. Ustilago maydis infection strongly alters organic nitrogen allocation in maize and stimulates productivity of systemic source leaves. PLANT PHYSIOLOGY 2010; 152:293-308. [PMID: 19923237 PMCID: PMC2799364 DOI: 10.1104/pp.109.147702] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Accepted: 11/12/2009] [Indexed: 05/20/2023]
Abstract
The basidiomycete Ustilago maydis is the causal agent of corn smut disease and induces tumor formation during biotrophic growth in its host maize (Zea mays). We have conducted a combined metabolome and transcriptome survey of infected leaves between 1 d post infection (dpi) and 8 dpi, representing infected leaf primordia and fully developed tumors, respectively. At 4 and 8 dpi, we observed a substantial increase in contents of the nitrogen-rich amino acids glutamine and asparagine, while the activities of enzymes involved in primary nitrogen assimilation and the content of ammonia and nitrate were reduced by 50% in tumors compared with mock controls. Employing stable isotope labeling, we could demonstrate that U. maydis-induced tumors show a reduced assimilation of soil-derived (15)NO(3)(-) and represent strong sinks for nitrogen. Specific labeling of the free amino acid pool of systemic source leaves with [(15)N]urea revealed an increased import of organic nitrogen from systemic leaves to tumor tissue, indicating that organic nitrogen provision supports the formation of U. maydis-induced tumors. In turn, amino acid export from systemic source leaves was doubled in infected plants. The analysis of the phloem amino acid pool revealed that glutamine and asparagine are not transported to the tumor tissue, although these two amino acids were found to accumulate within the tumor. Photosynthesis was increased and senescence was delayed in systemic source leaves upon tumor development on infected plants, indicating that the elevated sink demand for nitrogen could determine photosynthetic rates in source leaves.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Lars M. Voll
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Lehrstuhl für Biochemie, 91058 Erlangen, Germany (R.J.H., J.H., A.S., U.S., L.M.V.); Max Planck Institute for Terrestrial Microbiology, D–35043 Marburg, Germany (G.D., R.K.); and University of Karlsruhe, Institute of Applied Biosciences, Department of Genetics, 76187 Karlsruhe, Germany (R.W., J.K.)
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20
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van der Does HC, Duyvesteijn RG, Goltstein PM, van Schie CC, Manders EM, Cornelissen BJ, Rep M. Expression of effector gene SIX1 of Fusarium oxysporum requires living plant cells. Fungal Genet Biol 2008; 45:1257-64. [DOI: 10.1016/j.fgb.2008.06.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Revised: 06/06/2008] [Accepted: 06/10/2008] [Indexed: 10/21/2022]
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21
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Cross-species hybridization with Fusarium verticillioides microarrays reveals new insights into Fusarium fujikuroi nitrogen regulation and the role of AreA and NMR. EUKARYOTIC CELL 2008; 7:1831-46. [PMID: 18689524 DOI: 10.1128/ec.00130-08] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In filamentous fungi, the GATA-type transcription factor AreA plays a major role in the transcriptional activation of genes needed to utilize poor nitrogen sources. In Fusarium fujikuroi, AreA also controls genes involved in the biosynthesis of gibberellins, a family of diterpenoid plant hormones. To identify more genes responding to nitrogen limitation or sufficiency in an AreA-dependent or -independent manner, we examined changes in gene expression of F. fujikuroi wild-type and DeltaareA strains by use of a Fusarium verticillioides microarray representing approximately 9,300 genes. Analysis of the array data revealed sets of genes significantly down- and upregulated in the areA mutant under both N starvation and N-sufficient conditions. Among the downregulated genes are those involved in nitrogen metabolism, e.g., those encoding glutamine synthetase and nitrogen permeases, but also those involved in secondary metabolism. Besides AreA-dependent genes, we found an even larger set of genes responding to N starvation and N-sufficient conditions in an AreA-independent manner. To study the impact of NMR on AreA activity, we examined the expression of several AreA target genes in the wild type and in areA and nmr deletion and overexpression mutants. We show that NMR interacts with AreA as expected but affects gene expression only in early growth stages. This is the first report on genome-wide expression studies examining the influence of AreA on nitrogen-responsive gene expression in a genome-wide manner in filamentous fungi.
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Alkan N, Fluhr R, Sherman A, Prusky D. Role of ammonia secretion and pH modulation on pathogenicity of Colletotrichum coccodes on tomato fruit. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2008; 21:1058-66. [PMID: 18616402 DOI: 10.1094/mpmi-21-8-1058] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Colletotrichum coccodes was found to alkalinize the decaying tissue of tomato fruit via accumulation and secretion of ammonia. Alkalinization dynamics caused by ammonia secretion from growing hyphae was examined microscopically using the pH-sensitive fluorescent dye 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein. Values of pH of 7.9 observed in the host tissue close to the hyphal tips declined to pH 6.0 at 10 mm away from the hyphal tip, which was a value that was still higher than that detected in the healthy tissue, pH 4.2. Ammonia accumulation at the infection site depended on the initial environmental pH. Treatments with low (4.0) pH buffer at the infection site resulted in high levels of ammonia secretion and increased virulence of C. coccodes compared with similar treatments with buffer at pH 7.0. Significantly, mutants of C. coccodes defective in nitrogen utilization, nit-, and areA- were impaired in ammonia secretion and showed reduced decay development. The reduced infection rate of nit- mutants could be complemented by adding glutamine at the infection site. Thus, ammonia accumulation is a critical factor contributing to C. coccodes pathogenicity on tomato fruit. The results show that the initial acidic pH of the fruit is conducive to ammonia secretion and the subsequent alkalinization of the infection site, and facilitates fungal virulence and the transformation from the quiescent-biotrophic to active-necrotrophic state.
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Affiliation(s)
- N Alkan
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, the Volcani Center, Bet Dagan, Israel
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23
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Brown SH, Yarden O, Gollop N, Chen S, Zveibil A, Belausov E, Freeman S. Differential protein expression in Colletotrichum acutatum: changes associated with reactive oxygen species and nitrogen starvation implicated in pathogenicity on strawberry. MOLECULAR PLANT PATHOLOGY 2008; 9:171-90. [PMID: 18705850 PMCID: PMC6640448 DOI: 10.1111/j.1364-3703.2007.00454.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The cellular outcome of changes in nitrogen availability in the context of development and early stages of pathogenicity was studied by quantitative analysis of two-dimensional gel electrophoresis of Colletotrichum acutatum infecting strawberry. Significant alterations occurred in the abundance of proteins synthesized during appressorium formation under nitrogen-limiting conditions compared with a complete nutrient supply. Proteins that were up- or down-regulated were involved in energy metabolism, nitrogen and amino acid metabolism, protein synthesis and degradation, response to stress and reactive oxygen scavenging. Members belonging to the reactive oxygen species (ROS) scavenger machinery, superoxide dismutase and glutathione peroxidase, were up-regulated at the appressorium formation stage, as well as under nitrogen-limiting conditions relative to growth with a complete nutrient supply, whereas abundance of bifunctional catalase was up-regulated predominantly at the appressorium formation stage. Fungal ROS were detected within germinating conidia during host pre-penetration, penetration and colonization stages, accompanied by plant ROS, which were abundant in the apoplastic space. Application of exogenous antioxidants quenched ROS production and reduced the frequency of appressorium formation. Up-regulation in metabolic activity was detected during appressorium formation and nutrient deficiency compared with growth under complete nutrient supply. Enhanced levels of proteins related to the glyoxylate cycle and lipid metabolism (malate dehydrogenase, formate dehydrogenase and acetyl-CoA acetyltransferase) were observed at the appressorium formation stage, in contrast to down-regulation of isocitrate dehydrogenase. The present study demonstrates that appressoria formation processes, occurring under nutritional deprivation, are accompanied by metabolic shifts, and that ROS production is an early fungal response that may modulate initial stages of pathogen development.
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Affiliation(s)
- Sigal Horowitz Brown
- Department of Plant Pathology and Microbiology, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Rehovot 76100, Israel
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Browne RA, Brindle KM. H NMR-based metabolite profiling as a potential selection tool for breeding passive resistance against Fusarium head blight (FHB) in wheat. MOLECULAR PLANT PATHOLOGY 2007; 8:401-10. [PMID: 20507509 DOI: 10.1111/j.1364-3703.2007.00400.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
(1)H NMR measurements on protein-free extracts from wheat leaf and stem tissue were used to investigate the biochemical correlates of partial resistance to fungal species implicated in the Fusarium head blight (FHB) disease complex. The wheat genotypes included five commercial wheat cultivars and 116 wheat genotypes, from the CIMMYT international FHB breeding programme in Mexico, that had been bred for FHB disease resistance, utilizing exotic, typically Chinese, resistance sources. Principal component analysis of the nuclear magnetic resonance (NMR)-derived metabolite profiles revealed distinct separation of the commercial wheat cultivars from the majority of the CIMMYT wheat genotypes with the commercial cultivars exhibiting markedly higher carbohydrate concentrations. A cross-validated partial least squares (PLS) regression model of the metabolite profile against the partial disease resistance component latent period (delay in sporulation of the fungus on the plant tissue) predicted latent periods that were significantly correlated with the experimentally determined values (R(2) = 0.34, P < 0.001). Identified metabolites that were found in plants with shorter latent periods (higher disease susceptibility) included choline, the single most influential metabolite in the PLS model, betaine, the amino acids glutamine, glutamate and alanine, trans-aconitate and sucrose. Metabolites related to increased disease resistance included glucose and unassigned resonances in the carbohydrate and aromatic regions of the NMR spectra. The current study has demonstrated the potential of metabolite profiling as a tool for marker-assisted selection in commercial breeding for resistance to FHB in wheat.
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Affiliation(s)
- Roy A Browne
- Department of Biochemistry, Sanger Building, University of Cambridge, Cambridge CB2 1GA, UK.
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Abstract
Microarray studies have examined global gene expression in over 20 species of filamentous fungi encompassing a wide variety of research areas. The majority have addressed aspects of metabolism or pathogenicity. Metabolic studies have revealed important differences in the transcriptional regulation of genes for primary metabolic pathways between filamentous fungi and yeast. Transcriptional profiles for genes involved in secondary metabolism have also been established. Genes required for the biosynthesis of both useful and detrimental secondary metabolites have been identified. Due to the economic, ecological and medical implications, it is not surprising that many studies have used microarray analysis to examine gene expression in pathogenic filamentous fungi. Genes involved in various stages of pathogenicity have been identified, including those thought to be important for adaptation to the host environment. While most of the studies have simulated pathogenic conditions in vitro, a small number have also reported fungal gene expression within their plant hosts. This review summarizes the first 50 microarray studies in filamentous fungi and highlights areas for future investigation.
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Affiliation(s)
- Andrew Breakspear
- Department of Plant Biology, The University of Georgia, 1505 Miller Plant Sciences, Athens, GA 30602, USA
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Divon HH, Ziv C, Davydov O, Yarden O, Fluhr R. The global nitrogen regulator, FNR1, regulates fungal nutrition-genes and fitness during Fusarium oxysporum pathogenesis. MOLECULAR PLANT PATHOLOGY 2006; 7:485-97. [PMID: 20507463 DOI: 10.1111/j.1364-3703.2006.00354.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
SUMMARY Fusarium oxysporum is a soil-borne pathogen that infects plants through the roots and uses the vascular system for host ingress. Specialized for this route of infection, F. oxysporum is able to adapt to the scarce nutrient environment in the xylem vessels. Here we report the cloning of the F. oxysporum global nitrogen regulator, Fnr1, and show that it is one of the determinants for fungal fitness during in planta growth. The Fnr1 gene has a single conserved GATA-type zinc finger domain and is 96% and 48% identical to AREA-GF from Gibberella fujikuroi, and NIT2 from Neurospora crassa, respectively. Fnr1 cDNA, expressed under a constitutive promoter, was able to complement functionally an N. crassa nit-2(RIP) mutant, restoring the ability of the mutant to utilize nitrate. Fnr1 disruption mutants showed high tolerance to chlorate and reduced ability to utilize several secondary nitrogen sources such as amino acids, hypoxanthine and uric acid, whereas growth on favourable nitrogen sources was not affected. Fnr1 disruption also abolished in vitro expression of nutrition genes, normally induced during the early phase of infection. In an infection assay on tomato seedlings, infection rate of disruption mutants was significantly delayed in comparison with the parental strain. Our results indicate that FNR1 mediates adaptation to nitrogen-poor conditions in planta through the regulation of secondary nitrogen acquisition, and as such acts as a determinant for fungal fitness during infection.
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Affiliation(s)
- Hege Hvattum Divon
- Department of Plant Science, Weizmann Institute of Science, 76100 Rehovot, Israel
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Horowitz S, Freeman S, Zveibil A, Yarden O. A defect in nir1, a nirA-like transcription factor, confers morphological abnormalities and loss of pathogenicity in Colletotrichum acutatum. MOLECULAR PLANT PATHOLOGY 2006; 7:341-354. [PMID: 20507451 DOI: 10.1111/j.1364-3703.2006.00341.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
SUMMARY A non-pathogenic mutant of Colletotrichum acutatum, designated Ca5, exhibited epiphytic hyphal growth and did not cause lesions on strawberry plants but grew necrotrophically when inoculated directly onto wounded stolons. In the absence of an external nitrogen source, the mutant exhibited extended germ-tube growth prior to appressorium formation. The deduced product of the impaired gene (nir1) is similar to NirA, an Aspergillus nidulans transcriptional regulator of nitrogen metabolism. Inoculation of leaves with wild-type or Ca5 conidia in the presence of a preferred nitrogen source resulted in massive epiphytic hyphal production, appressorium formation and rapid symptom development. Expression of C. acutatum wild-type nitrate reductase (nit1) and glutamine synthetase (gln1) was induced by nitrate but only nit1 expression was repressed in a rich medium. nit1 transcription increased during the appressorium-production stage, indicating that nitrogen starvation constitutes a cue for the regulation of appressorium development. The presence of nit1 transcript during various phases of infection is indicative of partial nitrogen starvation in planta. cAMP-dependent protein kinase A (PKA) was determined to be a negative regulator of immediate post-germination appressoria formation in the wild-type. As inhibition of PKA activity in the nir1 mutant did not affect appressoria formation, we suggest that NIR1 acts either in parallel or downstream of the PKA pathway. Our results show that nir1 is a pathogenicity determinant and a regulator of pre-infection development under nitrogen-starvation conditions and that nitrogen availability is a significant factor in the pre-penetration phase.
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Affiliation(s)
- Sigal Horowitz
- Department of Plant Pathology and Microbiology, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Rehovot 76100, Israel
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McFadden HG, Wilson IW, Chapple RM, Dowd C. Fusarium wilt (Fusarium oxysporum f. sp. vasinfectum) genes expressed during infection of cotton (Gossypium hirsutum)dagger. MOLECULAR PLANT PATHOLOGY 2006; 7:87-101. [PMID: 20507430 DOI: 10.1111/j.1364-3703.2006.00327.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
SUMMARY We sought to identify Fusarium oxysporum f. sp. vasinfectum (Fov) genes that may be associated with pathogenicity. Initially we utilized microarray and Q-PCR technology to identify Fov genes expressed in root and hypocotyl tissues during a compatible infection of cotton. We identified 218 fungal clones representing 174 Fov non-redundant genes as expressed in planta. The majority of the expressed sequences were expressed in infected roots, with only six genes detected in hypocotyl tissue. The Fov genes identified were predominately of unknown function or associated with fungal growth and energy production. We then analysed the expression of the identified fungal genes in infected roots and in saprophytically grown mycelia and identified 11 genes preferentially expressed in plant tissue. A putative oxidoreductase gene (with homology to AtsC) was found to be highly preferentially expressed in planta. In Agrobacterium tumefaciens, AtsC is associated with virulence. Inoculation of a susceptible and a partially resistant cotton cultivar with either a pathogenic or a non-pathogenic isolate of Fov revealed that the expression of the Fov AtsC homologue was associated with pathogenicity and disease symptom formation.
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Affiliation(s)
- Helen G McFadden
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
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