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Stotz HU, Ali AM, de Lope LR, Rafi MS, Mitrousia GK, Huang YJ, Fitt BDL. Leptosphaeria maculans isolates with variations in AvrLm1 and AvrLm4 effector genes induce differences in defence responses but not in resistance phenotypes in cultivars carrying the Rlm7 gene. PEST MANAGEMENT SCIENCE 2024; 80:2435-2442. [PMID: 36869585 DOI: 10.1002/ps.7432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 02/16/2023] [Accepted: 03/04/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND The phoma stem canker pathogen Leptosphaeria maculans is one of the most widespread and devastating pathogens of oilseed rape (Brassica napus) in the world. Pathogen colonization is stopped by an interaction of a pathogen Avr effector gene with the corresponding host resistance (R) gene. While molecular mechanisms of this gene-for-gene interaction are being elucidated, understanding of effector function remains limited. The purpose of this study was to determine the action of L. maculans effector (AvrLm) genes on incompatible interactions triggered by B. napus noncorresponding R (Rlm) genes. Specifically, effects of AvrLm4-7 and AvrLm1 on Rlm7-mediated resistance were studied. RESULTS Although there was no major effect on symptom expression, induction of defence genes (e.g. PR1) and accumulation of reactive oxygen species was reduced when B. napus cv. Excel carrying Rlm7 was challenged with a L. maculans isolate containing AvrLm1 and a point mutation in AvrLm4-7 (AvrLm1, avrLm4-AvrLm7) compared to an isolate lacking AvrLm1 (avrLm1, AvrLm4-AvrLm7). AvrLm7-containing isolates, isogenic for presence or absence of AvrLm1, elicited similar symptoms on hosts with or without Rlm7, confirming results obtained with more genetically diverse isolates. CONCLUSION Careful phenotypic examination of isogenic L. maculans isolates and B. napus introgression lines demonstrated a lack of effect of AvrLm1 on Rlm7-mediated resistance despite an apparent alteration of the Rlm7-dependent defence response using more diverse fungal isolates with differences in AvrLm1 and AvrLm4. As deployment of Rlm7 resistance in crop cultivars increases, other effectors need to be monitored because they may alter the predominance of AvrLm7. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Henrik Uwe Stotz
- Centre for Agriculture, Food and Environmental Management, University of Hertfordshire, Hertfordshire, UK
| | - Ajisa Muthayil Ali
- Centre for Agriculture, Food and Environmental Management, University of Hertfordshire, Hertfordshire, UK
| | - Lucia Robado de Lope
- Centre for Agriculture, Food and Environmental Management, University of Hertfordshire, Hertfordshire, UK
| | - Mohammed Sajid Rafi
- Khalifa Center for Genetic Engineering and Biotechnology, United Arab Emirates University, Al Ain, PO Box 15551, United Arab Emirates
| | | | - Yong-Ju Huang
- Centre for Agriculture, Food and Environmental Management, University of Hertfordshire, Hertfordshire, UK
| | - Bruce David Ledger Fitt
- Centre for Agriculture, Food and Environmental Management, University of Hertfordshire, Hertfordshire, UK
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Singh G, Agrawal H, Bednarek P. Specialized metabolites as versatile tools in shaping plant-microbe associations. MOLECULAR PLANT 2023; 16:122-144. [PMID: 36503863 DOI: 10.1016/j.molp.2022.12.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 12/02/2022] [Accepted: 12/09/2022] [Indexed: 06/17/2023]
Abstract
Plants are rich repository of a large number of chemical compounds collectively referred to as specialized metabolites. These compounds are of importance for adaptive processes including responses against changing abiotic conditions and interactions with various co-existing organisms. One of the strikingly affirmed functions of these specialized metabolites is their involvement in plants' life-long interactions with complex multi-kingdom microbiomes including both beneficial and harmful microorganisms. Recent developments in genomic and molecular biology tools not only help to generate well-curated information about regulatory and structural components of biosynthetic pathways of plant specialized metabolites but also to create and screen mutant lines defective in their synthesis. In this review, we have comprehensively surveyed the function of these specialized metabolites and discussed recent research findings demonstrating the responses of various microbes on tested mutant lines having defective biosynthesis of particular metabolites. In addition, we attempt to provide key clues about the impact of these metabolites on the assembly of the plant microbiome by summarizing the major findings of recent comparative metagenomic analyses of available mutant lines under customized and natural microbial niches. Subsequently, we delineate benchmark initiatives that aim to engineer or manipulate the biosynthetic pathways to produce specialized metabolites in heterologous systems but also to diversify their immune function. While denoting the function of these metabolites, we also discuss the critical bottlenecks associated with understanding and exploiting their function in improving plant adaptation to the environment.
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Affiliation(s)
- Gopal Singh
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznań, Poland
| | - Himani Agrawal
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznań, Poland
| | - Paweł Bednarek
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznań, Poland.
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Kim C, Park J, Choi G, Kim S, Vo KTX, Jeon J, Kang S, Lee Y. A rice gene encoding glycosyl hydrolase plays contrasting roles in immunity depending on the type of pathogens. MOLECULAR PLANT PATHOLOGY 2022; 23:400-416. [PMID: 34839574 PMCID: PMC8828457 DOI: 10.1111/mpp.13167] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 11/10/2021] [Accepted: 11/10/2021] [Indexed: 05/09/2023]
Abstract
Because pathogens use diverse infection strategies, plants cannot use one-size-fits-all defence and modulate defence responses based on the nature of pathogens and pathogenicity mechanism. Here, we report that a rice glycoside hydrolase (GH) plays contrasting roles in defence depending on whether a pathogen is hemibiotrophic or necrotrophic. The Arabidopsis thaliana MORE1 (Magnaporthe oryzae resistance 1) gene, encoding a member of the GH10 family, is needed for resistance against M. oryzae and Alternaria brassicicola, a fungal pathogen infecting A. thaliana as a necrotroph. Among 13 rice genes homologous to MORE1, 11 genes were induced during the biotrophic or necrotrophic stage of infection by M. oryzae. CRISPR/Cas9-assisted disruption of one of them (OsMORE1a) enhanced resistance against hemibiotrophic pathogens M. oryzae and Xanthomonas oryzae pv. oryzae but increased susceptibility to Cochliobolus miyabeanus, a necrotrophic fungus, suggesting that OsMORE1a acts as a double-edged sword depending on the mode of infection (hemibiotrophic vs. necrotrophic). We characterized molecular and cellular changes caused by the loss of MORE1 and OsMORE1a to understand how these genes participate in modulating defence responses. Although the underlying mechanism of action remains unknown, both genes appear to affect the expression of many defence-related genes. Expression patterns of the GH10 family genes in A. thaliana and rice suggest that other members also participate in pathogen defence.
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Affiliation(s)
- Chi‐Yeol Kim
- Department of Agricultural BiotechnologySeoul National UniversitySeoulKorea
- Plant Immunity Research CenterSeoul National UniversitySeoulKorea
- Research Institute of Agriculture and Life SciencesSeoul National UniversitySeoulKorea
| | - Ju‐Young Park
- Department of Agricultural BiotechnologySeoul National UniversitySeoulKorea
| | - Gobong Choi
- Interdisciplinary Program in Agricultural GenomicsSeoul National UniversitySeoulKorea
| | - Seongbeom Kim
- Department of Agricultural BiotechnologySeoul National UniversitySeoulKorea
| | - Kieu Thi Xuan Vo
- Graduate School of Biotechnology and Crop Biotech InstituteKyung Hee UniversityYonginKorea
| | - Jong‐Seong Jeon
- Graduate School of Biotechnology and Crop Biotech InstituteKyung Hee UniversityYonginKorea
| | - Seogchan Kang
- Department of Plant Pathology and Environmental MicrobiologyPennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | - Yong‐Hwan Lee
- Department of Agricultural BiotechnologySeoul National UniversitySeoulKorea
- Plant Immunity Research CenterSeoul National UniversitySeoulKorea
- Research Institute of Agriculture and Life SciencesSeoul National UniversitySeoulKorea
- Interdisciplinary Program in Agricultural GenomicsSeoul National UniversitySeoulKorea
- Center for Fungal Genetic ResourcesSeoul National UniversitySeoulKorea
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Gay EJ, Soyer JL, Lapalu N, Linglin J, Fudal I, Da Silva C, Wincker P, Aury JM, Cruaud C, Levrel A, Lemoine J, Delourme R, Rouxel T, Balesdent MH. Large-scale transcriptomics to dissect 2 years of the life of a fungal phytopathogen interacting with its host plant. BMC Biol 2021; 19:55. [PMID: 33757516 PMCID: PMC7986464 DOI: 10.1186/s12915-021-00989-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 02/19/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The fungus Leptosphaeria maculans has an exceptionally long and complex relationship with its host plant, Brassica napus, during which it switches between different lifestyles, including asymptomatic, biotrophic, necrotrophic, and saprotrophic stages. The fungus is also exemplary of "two-speed" genome organisms in the genome of which gene-rich and repeat-rich regions alternate. Except for a few stages of plant infection under controlled conditions, nothing is known about the genes mobilized by the fungus throughout its life cycle, which may last several years in the field. RESULTS We performed RNA-seq on samples corresponding to all stages of the interaction of L. maculans with its host plant, either alive or dead (stem residues after harvest) in controlled conditions or in field experiments under natural inoculum pressure, over periods of time ranging from a few days to months or years. A total of 102 biological samples corresponding to 37 sets of conditions were analyzed. We show here that about 9% of the genes of this fungus are highly expressed during its interactions with its host plant. These genes are distributed into eight well-defined expression clusters, corresponding to specific infection lifestyles or to tissue-specific genes. All expression clusters are enriched in effector genes, and one cluster is specific to the saprophytic lifestyle on plant residues. One cluster, including genes known to be involved in the first phase of asymptomatic fungal growth in leaves, is re-used at each asymptomatic growth stage, regardless of the type of organ infected. The expression of the genes of this cluster is repeatedly turned on and off during infection. Whatever their expression profile, the genes of these clusters are enriched in heterochromatin regions associated with H3K9me3 or H3K27me3 repressive marks. These findings provide support for the hypothesis that part of the fungal genes involved in niche adaptation is located in heterochromatic regions of the genome, conferring an extreme plasticity of expression. CONCLUSION This work opens up new avenues for plant disease control, by identifying stage-specific effectors that could be used as targets for the identification of novel durable disease resistance genes, or for the in-depth analysis of chromatin remodeling during plant infection, which could be manipulated to interfere with the global expression of effector genes at crucial stages of plant infection.
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Affiliation(s)
- Elise J Gay
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, 78850, Thiverval-Grignon, France
| | - Jessica L Soyer
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, 78850, Thiverval-Grignon, France
| | - Nicolas Lapalu
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, 78850, Thiverval-Grignon, France
| | - Juliette Linglin
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, 78850, Thiverval-Grignon, France
| | - Isabelle Fudal
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, 78850, Thiverval-Grignon, France
| | - Corinne Da Silva
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Evry, Université Paris-Saclay, 91057, Evry, France
| | - Patrick Wincker
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Evry, Université Paris-Saclay, 91057, Evry, France
| | - Jean-Marc Aury
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Evry, Université Paris-Saclay, 91057, Evry, France
| | - Corinne Cruaud
- Genoscope, Institut François Jacob, CEA, Université Paris-Saclay, Evry, France
| | - Anne Levrel
- INRAE, Institut Agro, Univ Rennes, IGEPP, 35653, Le Rheu, France
| | - Jocelyne Lemoine
- INRAE, Institut Agro, Univ Rennes, IGEPP, 35653, Le Rheu, France
| | - Regine Delourme
- INRAE, Institut Agro, Univ Rennes, IGEPP, 35653, Le Rheu, France
| | - Thierry Rouxel
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, 78850, Thiverval-Grignon, France
| | - Marie-Hélène Balesdent
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, 78850, Thiverval-Grignon, France.
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Ouassou M, Mukhaimar M, El Amrani A, Kroymann J, Chauveau O. [Biosynthesis of indole glucosinolates and ecological role of secondary modification pathways]. C R Biol 2019; 342:58-80. [PMID: 31088733 DOI: 10.1016/j.crvi.2019.03.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 03/22/2019] [Accepted: 03/23/2019] [Indexed: 11/26/2022]
Abstract
Indole glucosinolates are plant secondary metabolites derived from the amino acid tryptophan. They are part of a large group of sulfur-containing molecules almost exclusively found among Brassicales, which include the mustard family (Brassicaceae) with many edible plant species of major nutritional importance. These compounds mediate numerous interactions between these plants and their natural enemies and are therefore of major biological and economical interest. This literature review aims at taking stock of recent advances of our knowledge about the biosynthetic pathways of indole glucosinolates, but also about the defense strategies and ecological processes involving these metabolites.
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Affiliation(s)
- Malika Ouassou
- Unité « Écologie, systématique et évolution », UMR 8079, université Paris-Sud, CNRS, AgroParisTech, université Paris-Saclay, 91405 Orsay, France; Laboratory of Biochemistry and Molecular Genetics, Department of Biology, Faculty of Science and Technics, Abdelmalek Essaadi University, Tangier, Maroc
| | - Maisara Mukhaimar
- National Agricultural Research Center (NARC)-Jenin/Gaza, Ministry of Agriculture, Jenin, Palestine
| | - Amal El Amrani
- Laboratory of Biochemistry and Molecular Genetics, Department of Biology, Faculty of Science and Technics, Abdelmalek Essaadi University, Tangier, Maroc
| | - Juergen Kroymann
- Unité « Écologie, systématique et évolution », UMR 8079, université Paris-Sud, CNRS, AgroParisTech, université Paris-Saclay, 91405 Orsay, France
| | - Olivier Chauveau
- Unité « Écologie, systématique et évolution », UMR 8079, université Paris-Sud, CNRS, AgroParisTech, université Paris-Saclay, 91405 Orsay, France.
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6
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Fang YL, Xia LM, Wang P, Zhu LH, Ye JR, Huang L. The MAPKKK CgMck1 Is Required for Cell Wall Integrity, Appressorium Development, and Pathogenicity in Colletotrichum gloeosporioides. Genes (Basel) 2018; 9:E543. [PMID: 30413120 PMCID: PMC6267176 DOI: 10.3390/genes9110543] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 11/04/2018] [Accepted: 11/05/2018] [Indexed: 12/21/2022] Open
Abstract
Mitogen-activated protein kinase (MAPK) signaling pathway plays key roles in sensing extracellular signals and transmitting them from the cell membrane to the nucleus in response to various environmental stimuli. A MAPKKK protein CgMck1 in Colletotrichum gloeosporioides was characterized. Phenotypic analyses of the ∆Cgmck1 mutant showed that the CgMck1 was required for vegetative growth, fruiting body development, and sporulation. Additionally, the CgMCK1 deletion mutant showed significant defects in cell wall integrity, and responses to osmotic stresses. The mutant abolished the ability to develop appressorium, and lost pathogenicity to host plants. The ∆Cgmck1 mutant also exhibited a higher sensitivity to antifungal bacterium agent Bacillus velezensis. The deletion mutants of downstream MAPK cascades components CgMkk1 and CgMps1 showed similar defects to the ∆Cgmck1 mutant. In conclusion, CgMck1 is involved in the regulation of vegetative growth, asexual development, cell wall integrity, stresses resistance, and infection morphogenesis in C. gloeosporioides.
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Affiliation(s)
- Yu-Lan Fang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, Jiangsu, China.
| | - Li-Ming Xia
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, Jiangsu, China.
| | - Ping Wang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, Jiangsu, China.
| | - Li-Hua Zhu
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, Jiangsu, China.
| | - Jian-Ren Ye
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, Jiangsu, China.
| | - Lin Huang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, Jiangsu, China.
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Brown NA, Urban M, Hammond-Kosack KE. The trans-kingdom identification of negative regulators of pathogen hypervirulence. FEMS Microbiol Rev 2016; 40:19-40. [PMID: 26468211 PMCID: PMC4703069 DOI: 10.1093/femsre/fuv042] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 06/30/2015] [Accepted: 09/03/2015] [Indexed: 01/08/2023] Open
Abstract
Modern society and global ecosystems are increasingly under threat from pathogens, which cause a plethora of human, animal, invertebrate and plant diseases. Of increasing concern is the trans-kingdom tendency for increased pathogen virulence that is beginning to emerge in natural, clinical and agricultural settings. The study of pathogenicity has revealed multiple examples of convergently evolved virulence mechanisms. Originally described as rare, but increasingly common, are interactions where a single gene deletion in a pathogenic species causes hypervirulence. This review utilised the pathogen-host interaction database (www.PHI-base.org) to identify 112 hypervirulent mutations from 37 pathogen species, and subsequently interrogates the trans-kingdom, conserved, molecular, biochemical and cellular themes that cause hypervirulence. This study investigates 22 animal and 15 plant pathogens including 17 bacterial and 17 fungal species. Finally, the evolutionary significance and trans-kingdom requirement for negative regulators of hypervirulence and the implication of pathogen hypervirulence and emerging infectious diseases on society are discussed.
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Affiliation(s)
- Neil A Brown
- Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, Herts AL5 2JQ, UK
| | - Martin Urban
- Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, Herts AL5 2JQ, UK
| | - Kim E Hammond-Kosack
- Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, Herts AL5 2JQ, UK
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Piasecka A, Jedrzejczak-Rey N, Bednarek P. Secondary metabolites in plant innate immunity: conserved function of divergent chemicals. THE NEW PHYTOLOGIST 2015; 206:948-964. [PMID: 25659829 DOI: 10.1111/nph.13325] [Citation(s) in RCA: 250] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 01/09/2015] [Indexed: 05/02/2023]
Abstract
Plant secondary metabolites carry out numerous functions in interactions between plants and a broad range of other organisms. Experimental evidence strongly supports the indispensable contribution of many constitutive and pathogen-inducible phytochemicals to plant innate immunity. Extensive studies on model plant species, particularly Arabidopsis thaliana, have brought significant advances in our understanding of the molecular mechanisms underpinning pathogen-triggered biosynthesis and activation of defensive secondary metabolites. However, despite the proven significance of secondary metabolites in plant response to pathogenic microorganisms, little is known about the precise mechanisms underlying their contribution to plant immunity. This insufficiency concerns information on the dynamics of cellular and subcellular localization of defensive phytochemicals during the encounters with microbial pathogens and precise knowledge on their mode of action. As many secondary metabolites are characterized by their in vitro antimicrobial activity, these compounds were commonly considered to function in plant defense as in planta antibiotics. Strikingly, recent experimental evidence suggests that at least some of these compounds alternatively may be involved in controlling several immune responses that are evolutionarily conserved in the plant kingdom, including callose deposition and programmed cell death.
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Affiliation(s)
- Anna Piasecka
- Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479, Poznan, Poland
| | - Nicolas Jedrzejczak-Rey
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznań, Poland
| | - Paweł Bednarek
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznań, Poland
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Feng J, Zhang H, Strelkov SE, Hwang SF. The LmSNF1 gene is required for pathogenicity in the canola blackleg pathogen Leptosphaeria maculans. PLoS One 2014; 9:e92503. [PMID: 24638039 PMCID: PMC3956939 DOI: 10.1371/journal.pone.0092503] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 02/21/2014] [Indexed: 11/19/2022] Open
Abstract
Leptosphaeria maculans is a fungal pathogen causing blackleg in canola. Its virulence has been attributed, among other factors, to the activity of hydrolytic cell wall degrading enzymes (CWDEs). Studies on the pathogenicity function of CWDEs in plant pathogenic fungi have been difficult due to gene redundancy. In microorganisms many CWDE genes are repressed by glucose and derepressed by the function of the sucrose non-fermenting protein kinase 1 gene (SNF1). To address the molecular function of SNF1 in L. maculans, the ortholog of SNF1 (LmSNF1) was cloned and functionally characterized using a gene knockout strategy. Growth of the LmSNF1 knockout strains was severely disrupted, as was sporulation, spore germination and the ability to attach on the plant surface. When inoculated on canola cotyledons, the LmSNF1 knockout strains could not cause any symptoms, indicating the loss of pathogenicity. The expression of 11 selected CWDE genes and a pathogenicity gene (LopB) was significantly down-regulated in the LmSNF1 knockout strains. In conclusion, knockout of LmSNF1 prevents L. maculans from properly derepressing the production of CWDEs, compromises the utilization of certain carbon sources, and impairs fungal pathogenicity on canola.
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Affiliation(s)
- Jie Feng
- Crop Diversification Centre North, Alberta Agriculture and Rural Development, Edmonton, Alberta, Canada
| | - Hui Zhang
- The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Stephen E. Strelkov
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Sheau-Fang Hwang
- Crop Diversification Centre North, Alberta Agriculture and Rural Development, Edmonton, Alberta, Canada
- * E-mail:
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10
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Nakano RT, Yamada K, Bednarek P, Nishimura M, Hara-Nishimura I. ER bodies in plants of the Brassicales order: biogenesis and association with innate immunity. FRONTIERS IN PLANT SCIENCE 2014; 5:73. [PMID: 24653729 PMCID: PMC3947992 DOI: 10.3389/fpls.2014.00073] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 02/12/2014] [Indexed: 05/20/2023]
Abstract
The endoplasmic reticulum (ER) forms highly organized network structures composed of tubules and cisternae. Many plant species develop additional ER-derived structures, most of which are specific for certain groups of species. In particular, a rod-shaped structure designated as the ER body is produced by plants of the Brassicales order, which includes Arabidopsis thaliana. Genetic analyses and characterization of A. thaliana mutants possessing a disorganized ER morphology or lacking ER bodies have provided insights into the highly organized mechanisms responsible for the formation of these unique ER structures. The accumulation of proteins specific for the ER body within the ER plays an important role in the formation of ER bodies. However, a mutant that exhibits morphological defects of both the ER and ER bodies has not been identified. This suggests that plants in the Brassicales order have evolved novel mechanisms for the development of this unique organelle, which are distinct from those used to maintain generic ER structures. In A. thaliana, ER bodies are ubiquitous in seedlings and roots, but rare in rosette leaves. Wounding of rosette leaves induces de novo formation of ER bodies, suggesting that these structures are associated with resistance against pathogens and/or herbivores. ER bodies accumulate a large amount of β-glucosidases, which can produce substances that potentially protect against invading pests. Biochemical studies have determined that the enzymatic activities of these β-glucosidases are enhanced during cell collapse. These results suggest that ER bodies are involved in plant immunity, although there is no direct evidence of this. In this review, we provide recent perspectives of ER and ER body formation in A. thaliana, and discuss clues for the functions of ER bodies. We highlight defense strategies against biotic stress that are unique for the Brassicales order, and discuss how ER structures could contribute to these strategies.
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Affiliation(s)
- Ryohei T. Nakano
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding ResearchCologne, Germany
| | - Kenji Yamada
- Department of Cell Biology, National Institute for Basic BiologyOkazaki, Japan
- Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies (Sokendai)Okazaki, Japan
| | - Paweł Bednarek
- Institute of Bioorganic Chemistry, Polish Academy of SciencesPoznañ, Poland
| | - Mikio Nishimura
- Department of Cell Biology, National Institute for Basic BiologyOkazaki, Japan
- Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies (Sokendai)Okazaki, Japan
| | - Ikuko Hara-Nishimura
- Department of Botany, Graduate School of Science, Kyoto UniversityKyoto, Japan
- *Correspondence: Ikuko Hara-Nishimura, Laboratory of Plant Molecular and Cell Biology, Department of Botany, Graduate School of Science, Kyoto University, Kita-Shirakawa Oiwake-cho, Sakyo-ku, 606-8502 Kyoto, Japan e-mail:
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Rouxel T, Balesdent MH. From model to crop plant-pathogen interactions: cloning of the first resistance gene to Leptosphaeria maculans in Brassica napus. THE NEW PHYTOLOGIST 2013; 197:356-358. [PMID: 23253328 DOI: 10.1111/nph.12099] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Affiliation(s)
- Thierry Rouxel
- INRA-Bioger, Av. Lucien Brétignières, 78850, Thiverval-Grignon, France
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12
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Bednarek P. Chemical warfare or modulators of defence responses - the function of secondary metabolites in plant immunity. CURRENT OPINION IN PLANT BIOLOGY 2012; 15:407-14. [PMID: 22445190 DOI: 10.1016/j.pbi.2012.03.002] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 02/29/2012] [Accepted: 03/01/2012] [Indexed: 05/21/2023]
Abstract
In plants, a host's responses to an attempted infection include activation of various secondary metabolite pathways, some of which are specific for particular plant phylogenetic clades. Phytochemicals that represent respective end products in plant immunity have been stereotypically linked to antimicrobial properties. However, in many cases, owing to the lack of unequivocal evidence for direct antibiotic action in planta, alternative functions of secondary metabolites should be considered. Correspondingly, recent findings have identified novel, and rather unexpected, functions of phytochemicals in plant immunity that mediate regulatory pathways for conserved defence responses. It also seems likely that these conserved responses can be regulated by clade-specific phytochemicals.
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Affiliation(s)
- Paweł Bednarek
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznań, Poland.
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Bednarek P. Sulfur-containing secondary metabolites from Arabidopsis thaliana and other Brassicaceae with function in plant immunity. Chembiochem 2012; 13:1846-59. [PMID: 22807086 DOI: 10.1002/cbic.201200086] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Indexed: 11/10/2022]
Abstract
Biosynthesis of antimicrobial secondary metabolites in response to microbial infection is one of the features of the plant immune system. Particular classes of plant secondary metabolites involved in plant defence are often produced only by species belonging to certain phylogenetic clades. Brassicaceae plants have evolved the ability to synthesise a wide range of sulfur-containing secondary metabolites, including glucosinolates and indole-type phytoalexins. A subset of these compounds is produced by the model plant Arabidopsis thaliana. Genetic tools available for this species enabled verification of immune functions of glucosinolates and camalexin (A. thaliana phytoalexin), as well as characterisation of their respective biosynthetic pathways. Current knowledge of the biosynthesis of Brassicaceae sulfur-containing metabolites suggests that the key event in the evolution of these compounds is the acquisition of biochemical mechanisms originating from detoxification pathways into secondary metabolite biosynthesis. Moreover, it is likely that glucosinolates and Brassicaceae phytoalexins, traditionally considered as separate groups of compounds, have a common evolutionary origin and are interconnected on the biosynthetic level. This suggests that the diversity of Brassicaceae sulfur-containing phytochemicals reflect phylogenetic clade-specific branches of an ancient biosynthetic pathway.
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Affiliation(s)
- Paweł Bednarek
- Laboratory of Proteomics and Metabolomics, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, Poznań, Poland.
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Elliott CE, Fox EM, Jarvis RS, Howlett BJ. The cross-pathway control system regulates production of the secondary metabolite toxin, sirodesmin PL, in the ascomycete, Leptosphaeria maculans. BMC Microbiol 2011; 11:169. [PMID: 21791055 PMCID: PMC3199737 DOI: 10.1186/1471-2180-11-169] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Accepted: 07/26/2011] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Sirodesmin PL is a secondary metabolite toxin made by the ascomycetous plant pathogen, Leptosphaeria maculans. The sirodesmin biosynthetic genes are clustered in the genome. The key genes are a non-ribosomal peptide synthetase, sirP, and a pathway-specific transcription factor, sirZ. Little is known about regulation of sirodesmin production. RESULTS Genes involved in regulation of sirodesmin PL in L. maculans have been identified. Two hundred random insertional T-DNA mutants were screened with an antibacterial assay for ones producing low levels of sirodesmin PL. Three such mutants were isolated and each transcribed sirZ at very low levels. One of the affected genes had high sequence similarity to Aspergillus fumigatus cpcA, which regulates the cross-pathway control system in response to amino acid availability. This gene was silenced in L. maculans and the resultant mutant characterised. When amino acid starvation was artificially-induced by addition of 3-aminotriazole for 5 h, transcript levels of sirP and sirZ did not change in the wild type. In contrast, levels of sirP and sirZ transcripts increased in the silenced cpcA mutant. After prolonged amino acid starvation the silenced cpcA mutant produced much higher amounts of sirodesmin PL than the wild type. CONCLUSIONS Production of sirodesmin PL in L. maculans is regulated by the cross pathway control gene, cpcA, either directly or indirectly via the pathway-specific transcription factor, sirZ.
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Affiliation(s)
- Candace E Elliott
- School of Botany, the University of Melbourne, Victoria, (3010), Australia
| | - Ellen M Fox
- School of Botany, the University of Melbourne, Victoria, (3010), Australia
- Department of Sustainability and Environment, Gippsland Regional Office, (71 Hotham Street), Traralgon, Victoria (3844), Australia
| | - Renee S Jarvis
- School of Botany, the University of Melbourne, Victoria, (3010), Australia
| | - Barbara J Howlett
- School of Botany, the University of Melbourne, Victoria, (3010), Australia
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Staal J, Dixelius C. RLM3, a potential adaptor between specific TIR-NB-LRR receptors and DZC proteins. Commun Integr Biol 2011; 1:59-61. [PMID: 19513199 DOI: 10.4161/cib.1.1.6394] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Accepted: 06/05/2008] [Indexed: 11/19/2022] Open
Abstract
In our recent paper, we identified a TIR encoding gene, which is required for resistance against a broad range of necrotrophic fungi. Here we present this finding in a broader perspective and discuss the unique features of this gene which might explain its role as a general regulator of resistance responses against a class of pathogens that have previously not been associated to the classical resistance (R) gene type of defense.
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Affiliation(s)
- Jens Staal
- Department of Molecular Biomedical Research; Unit for Molecular Signal Transduction in Inflammation; VIB; Ghent, Belgium
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Persson M, Staal J, Oide S, Dixelius C. Layers of defense responses to Leptosphaeria maculans below the RLM1- and camalexin-dependent resistances. THE NEW PHYTOLOGIST 2009; 182:470-482. [PMID: 19220763 DOI: 10.1111/j.1469-8137.2009.02763.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Plants have evolved different defense components to counteract pathogen attacks. The resistance locus resistance to Leptosphaeria maculans 1 (RLM1) is a key factor for Arabidopsis thaliana resistance to L. maculans. The present work aimed to reveal downstream defense responses regulated by RLM1. Quantitative assessment of fungal colonization in the host was carried out using quantitative polymerase chain reaction (qPCR) and GUS expression analyses, to further characterize RLM1 resistance and the role of salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) in disease development. Additional assessments of A. thaliana mutants were performed to expand our understanding of this pathosystem. Resistance responses such as lignification and the formation of vascular plugs were found to occur in an RLM1-dependent manner, in contrast to the RLM1-independent increase in reactive oxygen species at the stomata and hydathodes. Analyses of mutants defective in hormone signaling in the camalexin-free rlm1(Ler)pad3 background revealed a significant influence of JA and ET on symptom development and pathogen colonization. The overall results indicate that the defense responses of primary importance induced by RLM1 are all associated with physical barriers, and that responses of secondary importance involve complex cross-talk among SA, JA and ET. Our observations further suggest that ET positively affects fungal colonization.
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Affiliation(s)
- Mattias Persson
- Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences, PO Box 7080, 750 07 Uppsala, Sweden
| | - Jens Staal
- Department of Molecular Biomedical Research, Unit for Molecular Signal Transduction in Inflammation, VIB, Technologiepark 927, B-9052 Ghent (Zwijnaarde), Belgium
- Department of Molecular Biology, Ghent University, Technologiepark 927, B-9052 Ghent (Zwijnaarde), Belgium
| | - Shinichi Oide
- Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences, PO Box 7080, 750 07 Uppsala, Sweden
| | - Christina Dixelius
- Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences, PO Box 7080, 750 07 Uppsala, Sweden
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