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Zhang J, Li H, Gu W, Zhang K, Liu X, Liu M, Yang L, Li G, Zhang Z, Zhang H. Peroxisome dynamics determines host-derived ROS accumulation and infectious growth of the rice blast fungus. mBio 2023; 14:e0238123. [PMID: 37966176 PMCID: PMC10746245 DOI: 10.1128/mbio.02381-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Accepted: 10/05/2023] [Indexed: 11/16/2023] Open
Abstract
IMPORTANCE The interplay between plant and pathogen is a dynamic process, with the host's innate defense mechanisms serving a crucial role in preventing infection. In response to many plant pathogen infections, host cells generate the key regulatory molecule, reactive oxygen species (ROS), to limit the spread of the invading organism. In this study, we reveal the effects of fungal peroxisome dynamics on host ROS homeostasis, during the rice blast fungus Magnaporthe oryzae infection. The elongation of the peroxisome appears contingent upon ROS and links to the accumulation of ROS within the host and the infectious growth of the pathogen. Importantly, we identify a peroxisomal 3-ketoacyl-CoA thiolase, MoKat2, responsible for the elongation of the peroxisome during the infection. In response to host-derived ROS, the homodimer of MoKat2 undergoes dissociation to bind peroxisome membranes for peroxisome elongation. This process, in turn, inhibits the accumulation of host ROS, which is necessary for successful infection. Overall, our study is the first to highlight the intricate relationship between fungal organelle dynamics and ROS-mediated host immunity, extending the fundamental knowledge of pathogen-host interaction.
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Affiliation(s)
- Jun Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Huimin Li
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Wangliu Gu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Kexin Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Xinyu Liu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Muxing Liu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Leiyun Yang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Gang Li
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Zhengguang Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Haifeng Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
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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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3
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Petit-Houdenot Y, Degrave A, Meyer M, Blaise F, Ollivier B, Marais CL, Jauneau A, Audran C, Rivas S, Veneault-Fourrey C, Brun H, Rouxel T, Fudal I, Balesdent MH. A two genes - for - one gene interaction between Leptosphaeria maculans and Brassica napus. THE NEW PHYTOLOGIST 2019; 223:397-411. [PMID: 30802965 DOI: 10.1111/nph.15762] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Accepted: 02/18/2019] [Indexed: 05/26/2023]
Abstract
Interactions between Leptosphaeria maculans, causal agent of stem canker of oilseed rape, and its Brassica hosts are models of choice to explore the multiplicity of 'gene-for-gene' complementarities and how they diversified to increased complexity in the course of plant-pathogen co-evolution. Here, we support this postulate by investigating the AvrLm10 avirulence that induces a resistance response when recognized by the Brassica nigra resistance gene Rlm10. Using genome-assisted map-based cloning, we identified and cloned two AvrLm10 candidates as two genes in opposite transcriptional orientation located in a subtelomeric repeat-rich region of the genome. The AvrLm10 genes encode small secreted proteins and show expression profiles in planta similar to those of all L. maculans avirulence genes identified so far. Complementation and silencing assays indicated that both genes are necessary to trigger Rlm10 resistance. Three assays for protein-protein interactions showed that the two AvrLm10 proteins interact physically in vitro and in planta. Some avirulence genes are recognized by two distinct resistance genes and some avirulence genes hide the recognition specificities of another. Our L. maculans model illustrates an additional case where two genes located in opposite transcriptional orientation are necessary to induce resistance. Interestingly, orthologues exist for both L. maculans genes in other phytopathogenic species, with a similar genome organization, which may point to an important conserved effector function linked to heterodimerization of the two proteins.
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Affiliation(s)
- Yohann Petit-Houdenot
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Avenue Lucien Brétignières, BP 01, Thiverval-Grignon, F-78850, France
| | - Alexandre Degrave
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Avenue Lucien Brétignières, BP 01, Thiverval-Grignon, F-78850, France
| | - Michel Meyer
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Avenue Lucien Brétignières, BP 01, Thiverval-Grignon, F-78850, France
| | - Françoise Blaise
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Avenue Lucien Brétignières, BP 01, Thiverval-Grignon, F-78850, France
| | - Bénédicte Ollivier
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Avenue Lucien Brétignières, BP 01, Thiverval-Grignon, F-78850, France
| | - Claire-Line Marais
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Avenue Lucien Brétignières, BP 01, Thiverval-Grignon, F-78850, France
| | - Alain Jauneau
- Plateforme Imagerie, Pôle de Biotechnologie Végétale, Fédération de Recherche 3450, Castanet-Tolosan, F-31326, France
| | - Corinne Audran
- LIPM, Université de Toulouse, INRA, CNRS, Castanet-Tolosan, F-31326, France
| | - Susana Rivas
- LIPM, Université de Toulouse, INRA, CNRS, Castanet-Tolosan, F-31326, France
| | - Claire Veneault-Fourrey
- Laboratoire d'Excellence ARBRE, Centre INRA-Lorraine, INRA, UMR 1136, INRA-Université de Lorraine Interactions Arbres/Microorganismes, Champenoux, F-54280, France
- Laboratoire d'Excellence ARBRE, Faculté des Sciences et Technologies, UMR 1136 INRA-Université de Lorraine Interactions Arbres/Microorganismes, Université de Lorraine, Vandoeuvre les Nancy, F-54506, France
| | | | - Thierry Rouxel
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Avenue Lucien Brétignières, BP 01, Thiverval-Grignon, F-78850, France
| | - Isabelle Fudal
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Avenue Lucien Brétignières, BP 01, Thiverval-Grignon, F-78850, France
| | - Marie-Hélène Balesdent
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Avenue Lucien Brétignières, BP 01, Thiverval-Grignon, F-78850, France
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Urquhart AS, Hu J, Chooi YH, Idnurm A. The fungal gene cluster for biosynthesis of the antibacterial agent viriditoxin. Fungal Biol Biotechnol 2019; 6:2. [PMID: 31304040 PMCID: PMC6600887 DOI: 10.1186/s40694-019-0072-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Accepted: 06/12/2019] [Indexed: 11/20/2022] Open
Abstract
Background Viriditoxin is one of the ‘classical’ secondary metabolites produced by fungi and that has antibacterial and other activities; however, the mechanism of its biosynthesis has remained unknown. Results Here, a gene cluster (vdt) responsible for viriditoxin synthesis was identified, via a bioinformatics analysis of the genomes of Paecilomyces variotii and Aspergillus viridinutans that both are viriditoxin producers. The function of the eight-membered gene cluster of P. variotii was characterized by targeted gene disruptions, revealing the roles of each gene in the synthesis of this molecule and establishing its biosynthetic pathway, which includes a Baeyer–Villiger monooxygenase catalyzed reaction. Additionally, a predicted catalytically-inactive hydrolase was identified as being required for the stereoselective biosynthesis of (M)-viriditoxin. The subcellular localizations of two proteins (VdtA and VdtG) were determined by fusing these proteins to green fluorescent protein, to establish that at least two intracellular structures are involved in the compartmentalization of the synthesis steps of this metabolite. Conclusions The predicted pathway for the synthesis of viriditoxin was established by a combination of genomics, bioinformatics, gene disruption and chemical analysis processes. Hence, this work reveals the basis for the synthesis of an understudied class of fungal secondary metabolites and provides a new model species for understanding the synthesis of biaryl compounds with a chiral axis. Electronic supplementary material The online version of this article (10.1186/s40694-019-0072-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Andrew S Urquhart
- 1School of BioSciences, University of Melbourne, Melbourne, Australia
| | - Jinyu Hu
- 2School of Molecular Sciences, University of Western Australia, Perth, Australia
| | - Yit-Heng Chooi
- 2School of Molecular Sciences, University of Western Australia, Perth, Australia
| | - Alexander Idnurm
- 1School of BioSciences, University of Melbourne, Melbourne, Australia
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Van de Wouw AP, Elliott CE, Popa KM, Idnurm A. Analysis of Repeat Induced Point (RIP) Mutations in Leptosphaeria maculans Indicates Variability in the RIP Process Between Fungal Species. Genetics 2019; 211:89-104. [PMID: 30389803 PMCID: PMC6325690 DOI: 10.1534/genetics.118.301712] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 10/24/2018] [Indexed: 01/01/2023] Open
Abstract
Gene duplication contributes to evolutionary potential, yet many duplications in a genome arise from the activity of "selfish" genetic elements such as transposable elements. Fungi have a number of mechanisms by which they limit the expansion of transposons, including Repeat Induced Point mutation (RIP). RIP has been best characterized in the Sordariomycete Neurospora crassa, wherein duplicated DNA regions are recognized after cell fusion, but before nuclear fusion during the sexual cycle, and then mutated. While "signatures" of RIP appear in the genome sequences of many fungi, the species most distant from N. crassa in which the process has been experimentally demonstrated to occur is the Dothideomycete Leptosphaeria maculans In the current study, we show that similar to N. crassa, nonlinked duplications can trigger RIP; however, the frequency of the generated RIP mutations is extremely low in L maculans (< 0.1%) and requires a large duplication to initiate RIP, and that multiple premeiotic mitoses are involved in the RIP process. However, a single sexual cycle leads to the generation of progeny with unique haplotypes, despite progeny pairs being generated from mitosis. We hypothesize that these different haplotypes may be the result of the deamination process occurring post karyogamy, leading to unique mutations within each of the progeny pairs. These findings indicate that the RIP process, while common to many fungi, differs between fungi and that this impacts on the fate of duplicated DNA.
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Affiliation(s)
- Angela P Van de Wouw
- School of BioSciences, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Candace E Elliott
- School of BioSciences, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Kerryn M Popa
- School of BioSciences, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Alexander Idnurm
- School of BioSciences, The University of Melbourne, Parkville, Victoria 3010, Australia
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Idnurm A, Urquhart AS, Vummadi DR, Chang S, Van de Wouw AP, López-Ruiz FJ. Spontaneous and CRISPR/Cas9-induced mutation of the osmosensor histidine kinase of the canola pathogen Leptosphaeria maculans. Fungal Biol Biotechnol 2017; 4:12. [PMID: 29270298 PMCID: PMC5732519 DOI: 10.1186/s40694-017-0043-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 12/12/2017] [Indexed: 12/30/2022] Open
Abstract
Background The dicarboximide fungicide iprodione has been used to combat blackleg disease of canola (Brassica napus), caused by the fungus Leptosphaeria maculans. For example, in Australia the fungicide was used in the late 1990s but is no longer registered for use against blackleg disease, and therefore the impact of iprodione on L. maculans has not been investigated. Results Resistance to iprodione emerged spontaneously under in vitro conditions at high frequency. A basis for this resistance was mutations in the hos1 gene that encodes a predicted osmosensing histidine kinase. While loss of the homologous histidine kinase in some fungi has deleterious effects on growth and pathogenicity, the L. maculans strains with the hos1 gene mutated had reduced growth under high salt conditions, but were still capable of causing lesions on B. napus. The relative ease to isolate mutants with resistance to iprodione provided a method to develop and then optimize a CRISPR/Cas9 system for gene disruptions in L. maculans, a species that until now has been particularly difficult to manipulate by targeted gene disruptions. Conclusions While iprodione is initially effective against L. maculans in vitro, resistance emerges easily and these strains are able to cause lesions on canola. This may explain the limited efficacy of iprodione in field conditions. Iprodione resistance, such as through mutations of genes like hos1, provides an effective direction for the optimization of gene disruption techniques.
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Affiliation(s)
- Alexander Idnurm
- School of BioSciences, University of Melbourne, Building 122, Parkville, VIC 3010 Australia
| | - Andrew S Urquhart
- School of BioSciences, University of Melbourne, Building 122, Parkville, VIC 3010 Australia
| | - Dinesh R Vummadi
- School of BioSciences, University of Melbourne, Building 122, Parkville, VIC 3010 Australia
| | - Steven Chang
- Department of Environment and Agriculture, Centre for Crop and Disease Management, Curtin University, Bentley, WA 6102 Australia
| | - Angela P Van de Wouw
- School of BioSciences, University of Melbourne, Building 122, Parkville, VIC 3010 Australia
| | - Francisco J López-Ruiz
- Department of Environment and Agriculture, Centre for Crop and Disease Management, Curtin University, Bentley, WA 6102 Australia
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7
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Idnurm A, Bailey AM, Cairns TC, Elliott CE, Foster GD, Ianiri G, Jeon J. A silver bullet in a golden age of functional genomics: the impact of Agrobacterium-mediated transformation of fungi. Fungal Biol Biotechnol 2017; 4:6. [PMID: 28955474 PMCID: PMC5615635 DOI: 10.1186/s40694-017-0035-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 09/18/2017] [Indexed: 11/10/2022] Open
Abstract
The implementation of Agrobacterium tumefaciens as a transformation tool revolutionized approaches to discover and understand gene functions in a large number of fungal species. A. tumefaciens mediated transformation (AtMT) is one of the most transformative technologies for research on fungi developed in the last 20 years, a development arguably only surpassed by the impact of genomics. AtMT has been widely applied in forward genetics, whereby generation of strain libraries using random T-DNA insertional mutagenesis, combined with phenotypic screening, has enabled the genetic basis of many processes to be elucidated. Alternatively, AtMT has been fundamental for reverse genetics, where mutant isolates are generated with targeted gene deletions or disruptions, enabling gene functional roles to be determined. When combined with concomitant advances in genomics, both forward and reverse approaches using AtMT have enabled complex fungal phenotypes to be dissected at the molecular and genetic level. Additionally, in several cases AtMT has paved the way for the development of new species to act as models for specific areas of fungal biology, particularly in plant pathogenic ascomycetes and in a number of basidiomycete species. Despite its impact, the implementation of AtMT has been uneven in the fungi. This review provides insight into the dynamics of expansion of new research tools into a large research community and across multiple organisms. As such, AtMT in the fungi, beyond the demonstrated and continuing power for gene discovery and as a facile transformation tool, provides a model to understand how other technologies that are just being pioneered, e.g. CRISPR/Cas, may play roles in fungi and other eukaryotic species.
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Affiliation(s)
- Alexander Idnurm
- School of BioSciences, University of Melbourne, Melbourne, VIC 3010 Australia
| | - Andy M. Bailey
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Timothy C. Cairns
- Department of Applied and Molecular Microbiology, Technische Universität Berlin, Berlin, Germany
| | - Candace E. Elliott
- School of BioSciences, University of Melbourne, Melbourne, VIC 3010 Australia
| | - Gary D. Foster
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Giuseppe Ianiri
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, USA
| | - Junhyun Jeon
- College of Life and Applied Sciences, Yeungnam University, Gyeongsan, South Korea
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Urquhart AS, Idnurm A. Sit4-Associated Protein is Required for Pathogenicity of Leptosphaeria maculans on Brassica napus. Curr Microbiol 2017; 74:1438-1446. [PMID: 28840344 DOI: 10.1007/s00284-017-1338-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Accepted: 08/16/2017] [Indexed: 11/28/2022]
Abstract
An insertional mutant with reduced pathogenicity on Brassica napus was identified in the plant pathogenic fungus Leptosphaeria maculans. The transfer-DNA molecule from Agrobacterium tumefaciens inserted into a gene encoding a protein with similarity to Sit4-associated proteins (SAPs). In contrast to Saccharomyces cerevisiae which has four members of the SAP family, there is a single copy of the gene in L. maculans. The mutant had normal spore production and spore germination, but altered hyphal branching, suggesting that nutrient signaling is impaired in the strain. This is the first time that a SAP gene has been mutated in a filamentous fungus and links the function of SAP proteins to plant pathogenesis and hyphal branching.
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Affiliation(s)
- Andrew S Urquhart
- School of BioSciences, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Alexander Idnurm
- School of BioSciences, University of Melbourne, Parkville, VIC, 3010, Australia.
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9
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Blum A, Benfield AH, Stiller J, Kazan K, Batley J, Gardiner DM. High-throughput FACS-based mutant screen identifies a gain-of-function allele of the Fusarium graminearum adenylyl cyclase causing deoxynivalenol over-production. Fungal Genet Biol 2016; 90:1-11. [PMID: 26932301 DOI: 10.1016/j.fgb.2016.02.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 02/02/2016] [Accepted: 02/26/2016] [Indexed: 01/21/2023]
Abstract
Fusarium head blight and crown rot, caused by the fungal plant pathogen Fusarium graminearum, impose a major threat to global wheat production. During the infection, plants are contaminated with mycotoxins such as deoxynivalenol (DON), which can be toxic for humans and animals. In addition, DON is a major virulence factor during wheat infection. However, it is not fully understood how DON production is regulated in F. graminearum. In order to identify regulators of DON production, a high-throughput mutant screen using Fluorescence Activated Cell Sorting (FACS) of a mutagenised TRI5-GFP reporter strain was established and a mutant over-producing DON under repressive conditions identified. A gain-of-function mutation in the F. graminearum adenylyl cyclase (FAC1), which is a known positive regulator of DON production, was identified as the cause of this phenotype through genome sequencing and segregation analysis. Our results show that the high-throughput mutant screening procedure developed here can be applied for identification of fungal proteins involved in diverse processes.
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Affiliation(s)
- Ailisa Blum
- CSIRO Agriculture, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia, Brisbane, Queensland 4067, Australia; School of Agriculture & Food Sciences, University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
| | - Aurélie H Benfield
- CSIRO Agriculture, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia, Brisbane, Queensland 4067, Australia
| | - Jiri Stiller
- CSIRO Agriculture, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia, Brisbane, Queensland 4067, Australia
| | - Kemal Kazan
- CSIRO Agriculture, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia, Brisbane, Queensland 4067, Australia; Queensland Alliance for Agriculture & Food Innovation (QAAFI), University of Queensland, St Lucia, Brisbane, Queensland 4067, Australia
| | - Jacqueline Batley
- School of Agriculture & Food Sciences, University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia; School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Donald M Gardiner
- CSIRO Agriculture, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia, Brisbane, Queensland 4067, Australia
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Shiller J, Van de Wouw AP, Taranto AP, Bowen JK, Dubois D, Robinson A, Deng CH, Plummer KM. A Large Family of AvrLm6-like Genes in the Apple and Pear Scab Pathogens, Venturia inaequalis and Venturia pirina. FRONTIERS IN PLANT SCIENCE 2015; 6:980. [PMID: 26635823 PMCID: PMC4646964 DOI: 10.3389/fpls.2015.00980] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 10/26/2015] [Indexed: 05/19/2023]
Abstract
Venturia inaequalis and V. pirina are Dothideomycete fungi that cause apple scab and pear scab disease, respectively. Whole genome sequencing of V. inaequalis and V. pirina isolates has revealed predicted proteins with sequence similarity to AvrLm6, a Leptosphaeria maculans effector that triggers a resistance response in Brassica napus and B. juncea carrying the resistance gene, Rlm6. AvrLm6-like genes are present as large families (>15 members) in all sequenced strains of V. inaequalis and V. pirina, while in L. maculans, only AvrLm6 and a single paralog have been identified. The Venturia AvrLm6-like genes are located in gene-poor regions of the genomes, and mostly in close proximity to transposable elements, which may explain the expansion of these gene families. An AvrLm6-like gene from V. inaequalis with the highest sequence identity to AvrLm6 was unable to trigger a resistance response in Rlm6-carrying B. juncea. RNA-seq and qRT-PCR gene expression analyses, of in planta- and in vitro-grown V. inaequalis, has revealed that many of the AvrLm6-like genes are expressed during infection. An AvrLm6 homolog from V. inaequalis that is up-regulated during infection was shown (using an eYFP-fusion protein construct) to be localized to the sub-cuticular stroma during biotrophic infection of apple hypocotyls.
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Affiliation(s)
- Jason Shiller
- Animal, Plant and Soil Sciences Department, AgriBio, AgriBiosciences Research Centre, La Trobe University, MelbourneVIC, Australia
| | | | - Adam P. Taranto
- Animal, Plant and Soil Sciences Department, AgriBio, AgriBiosciences Research Centre, La Trobe University, MelbourneVIC, Australia
- Plant Sciences Division, Research School of Biology, The Australian National University, CanberraACT, Australia
| | - Joanna K. Bowen
- The New Zealand Institute for Plant and Food Research LimitedAuckland, New Zealand
| | - David Dubois
- School of BioSciences, University of Melbourne, ParkvilleVIC, Australia
| | - Andrew Robinson
- Animal, Plant and Soil Sciences Department, AgriBio, AgriBiosciences Research Centre, La Trobe University, MelbourneVIC, Australia
- Life Sciences Computation Centre, Victorian Life Sciences Computation Initiative, MelbourneVIC, Australia
| | - Cecilia H. Deng
- The New Zealand Institute for Plant and Food Research LimitedAuckland, New Zealand
| | - Kim M. Plummer
- Animal, Plant and Soil Sciences Department, AgriBio, AgriBiosciences Research Centre, La Trobe University, MelbourneVIC, Australia
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Zhong Z, Norvienyeku J, Yu J, Chen M, Cai R, Hong Y, Chen L, Zhang D, Wang B, Zhou J, Lu G, Chen X, Wang Z. Two different subcellular-localized Acetoacetyl-CoA acetyltransferases differentiate diverse functions in Magnaporthe oryzae. Fungal Genet Biol 2015; 83:58-67. [DOI: 10.1016/j.fgb.2015.08.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 08/23/2015] [Accepted: 08/24/2015] [Indexed: 10/23/2022]
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Van de Wouw AP, Lowe RGT, Elliott CE, Dubois DJ, Howlett BJ. An avirulence gene, AvrLmJ1, from the blackleg fungus, Leptosphaeria maculans, confers avirulence to Brassica juncea cultivars. MOLECULAR PLANT PATHOLOGY 2014; 15:523-30. [PMID: 24279453 PMCID: PMC6638781 DOI: 10.1111/mpp.12105] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The fungus Leptosphaeria maculans causes blackleg of Brassica species. Here, we report the mapping and subsequent cloning of an avirulence gene from L. maculans. This gene, termed AvrLmJ1, confers avirulence towards all three Brassica juncea cultivars tested. Analysis of RNA-seq data showed that AvrLmJ1 is housed in a region of the L. maculans genome which contains only one gene that is highly expressed in planta. The closest genes are 57 and 33 kb away and, like other avirulence genes of L. maculans, AvrLmJ1 is located within an AT-rich, gene-poor region of the genome. The encoded protein is 141 amino acids, has a predicted signal peptide and is cysteine rich. Two virulent isolates contain a premature stop codon in AvrLmJ1. Complementation of an isolate that forms cotyledonary lesions on B. juncea with the wild-type allele of AvrLmJ1 confers avirulence towards all three B. juncea cultivars tested, suggesting that the gene may confer species-specific avirulence activity.
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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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Incidence of genome structure, DNA asymmetry, and cell physiology on T-DNA integration in chromosomes of the phytopathogenic fungus Leptosphaeria maculans. G3-GENES GENOMES GENETICS 2012; 2:891-904. [PMID: 22908038 PMCID: PMC3411245 DOI: 10.1534/g3.112.002048] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2012] [Accepted: 06/07/2012] [Indexed: 11/18/2022]
Abstract
The ever-increasing generation of sequence data is accompanied by unsatisfactory functional annotation, and complex genomes, such as those of plants and filamentous fungi, show a large number of genes with no predicted or known function. For functional annotation of unknown or hypothetical genes, the production of collections of mutants using Agrobacterium tumefaciens–mediated transformation (ATMT) associated with genotyping and phenotyping has gained wide acceptance. ATMT is also widely used to identify pathogenicity determinants in pathogenic fungi. A systematic analysis of T-DNA borders was performed in an ATMT-mutagenized collection of the phytopathogenic fungus Leptosphaeria maculans to evaluate the features of T-DNA integration in its particular transposable element-rich compartmentalized genome. A total of 318 T-DNA tags were recovered and analyzed for biases in chromosome and genic compartments, existence of CG/AT skews at the insertion site, and occurrence of microhomologies between the T-DNA left border (LB) and the target sequence. Functional annotation of targeted genes was done using the Gene Ontology annotation. The T-DNA integration mainly targeted gene-rich, transcriptionally active regions, and it favored biological processes consistent with the physiological status of a germinating spore. T-DNA integration was strongly biased toward regulatory regions, and mainly promoters. Consistent with the T-DNA intranuclear-targeting model, the density of T-DNA insertion correlated with CG skew near the transcription initiation site. The existence of microhomologies between promoter sequences and the T-DNA LB flanking sequence was also consistent with T-DNA integration to host DNA mediated by homologous recombination based on the microhomology-mediated end-joining pathway.
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Defects in mitochondrial and peroxisomal β-oxidation influence virulence in the maize pathogen Ustilago maydis. EUKARYOTIC CELL 2012; 11:1055-66. [PMID: 22707484 DOI: 10.1128/ec.00129-12] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
An understanding of metabolic adaptation during the colonization of plants by phytopathogenic fungi is critical for developing strategies to protect crops. Lipids are abundant in plant tissues, and fungal phytopathogens in the phylum basidiomycota possess both peroxisomal and mitochondrial β-oxidation pathways to utilize this potential carbon source. Previously, we demonstrated a role for the peroxisomal β-oxidation enzyme Mfe2 in the filamentous growth, virulence, and sporulation of the maize pathogen Ustilago maydis. However, mfe2 mutants still caused disease symptoms, thus prompting a more detailed investigation of β-oxidation. We now demonstrate that a defect in the had1 gene encoding hydroxyacyl coenzyme A dehydrogenase for mitochondrial β-oxidation also influences virulence, although its paralog, had2, makes only a minor contribution. Additionally, we identified a gene encoding a polypeptide with similarity to the C terminus of Mfe2 and designated it Mfe2b; this gene makes a contribution to virulence only in the background of an mfe2Δ mutant. We also show that short-chain fatty acids induce cell death in U. maydis and that a block in β-oxidation leads to toxicity, likely because of the accumulation of toxic intermediates. Overall, this study reveals that β-oxidation has a complex influence on the formation of disease symptoms by U. maydis that includes potential metabolic contributions to proliferation in planta and an effect on virulence-related morphogenesis.
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Frandsen RJN. A guide to binary vectors and strategies for targeted genome modification in fungi using Agrobacterium tumefaciens-mediated transformation. J Microbiol Methods 2011; 87:247-62. [DOI: 10.1016/j.mimet.2011.09.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 09/09/2011] [Accepted: 09/09/2011] [Indexed: 01/31/2023]
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Kidd BN, Kadoo NY, Dombrecht B, Tekeoglu M, Gardiner DM, Thatcher LF, Aitken EAB, Schenk PM, Manners JM, Kazan K. Auxin signaling and transport promote susceptibility to the root-infecting fungal pathogen Fusarium oxysporum in Arabidopsis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2011; 24:733-48. [PMID: 21281113 DOI: 10.1094/mpmi-08-10-0194] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Fusarium oxysporum is a root-infecting fungal pathogen that causes wilt disease on a broad range of plant species, including the model plant Arabidopsis thaliana. Currently, very little is known about the molecular or physiological processes that are activated in the host during infection and the roles these processes play in resistance and susceptibility to F. oxysporum. In this study, we analyzed global gene expression profiles of F. oxysporum-infected Arabidopsis plants. Genes involved in jasmonate biosynthesis as well as jasmonate-dependent defense were coordinately induced by F. oxysporum. Similarly, tryptophan pathway genes, including those involved in both indole-glucosinolate and auxin biosynthesis, were upregulated in both the leaves and the roots of inoculated plants. Analysis of plants expressing the DR5:GUS construct suggested that root auxin homeostasis was altered during F. oxysporum infection. However, Arabidopsis mutants with altered auxin and tryptophan-derived metabolites such as indole-glucosinolates and camalexin did not show an altered resistance to this pathogen. In contrast, several auxin-signaling mutants were more resistant to F. oxysporum. Chemical or genetic alteration of polar auxin transport also conferred increased pathogen resistance. Our results suggest that, similarly to many other pathogenic and nonpathogenic or beneficial soil organisms, F. oxysporum requires components of auxin signaling and transport to colonize the plant more effectively. Potential mechanisms of auxin signaling and transport-mediated F. oxysporum susceptibility are discussed.
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Affiliation(s)
- Brendan N Kidd
- Commonwealth Scientific and Industrial Research Organization Plant Industy, Queensland Bioscience Precint, St Lucia, Australia
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Gardiner DM, Kazan K, Manners JM. Nutrient profiling reveals potent inducers of trichothecene biosynthesis in Fusarium graminearum. Fungal Genet Biol 2009; 46:604-13. [DOI: 10.1016/j.fgb.2009.04.004] [Citation(s) in RCA: 194] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Revised: 04/17/2009] [Accepted: 04/19/2009] [Indexed: 11/25/2022]
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Remy E, Meyer M, Blaise F, Simon UK, Kuhn D, Balesdent MH, Rouxel T. A key enzyme of the Leloir pathway is involved in pathogenicity of Leptosphaeria maculans toward oilseed rape. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2009; 22:725-36. [PMID: 19445597 DOI: 10.1094/mpmi-22-6-0725] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Agrobacterium tumefaciens-mediated random insertional mutagenesis was used to investigate pathogenicity determinants in Leptosphaeria maculans. One tagged nonpathogenic mutant, termed m186, is analyzed in detail here. Microscopic analyses of infected plant tissues revealed that m186 is specifically blocked at the invasive growth phase after an unaffected initial penetration stage and is unable to switch to the necrotrophic lifestyle. In addition, m186 exhibits an altered cell wall and seems to be affected in its ability to produce cell-wall-degrading enzymes. The T-DNA insertion occurs in the intergenic region between two head-to-tail genes, leading to a constitutive upregulation of their expression. Complementation experiments showed that only one of these two genes, Lmepi, fully accounts for the mutant phenotype. Bioinformatics and expression analyses along with functional studies suggested that the Lmepi gene encodes for the highly conserved UDP-glucose-4-epimerase, a key enzyme of the Leloir pathway involved in galactose metabolism. For the third time, this study highlights the intimate connection between primary metabolism and pathogenicity in L. maculans. This finding, along with similar data obtained from the related species Stagonospora nodorum, indicates the importance of in planta nutrition for the success of infection of plants by fungi belonging to class Dothideomycete.
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Affiliation(s)
- E Remy
- INRA, UMR 1290 BIOGER, F-78026 Versailles cedex, France
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20
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The Lmpma1 gene of Leptosphaeria maculans encodes a plasma membrane H+-ATPase isoform essential for pathogenicity towards oilseed rape. Fungal Genet Biol 2008; 45:1122-34. [PMID: 18538267 DOI: 10.1016/j.fgb.2008.04.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2008] [Revised: 04/05/2008] [Accepted: 04/10/2008] [Indexed: 11/22/2022]
Abstract
Following Agrobacterium tumefaciens-mediated mutagenesis in Leptosphaeria maculans, we identified the mutant 210, displaying total loss of pathogenicity towards its host plant (Brassica napus). Microscopic observations showed that m210 is unable to germinate on the host leaf surface and is thus blocked at the pre-penetration stage. The pathogenicity phenotype is linked with a single T-DNA insertion into the promoter region of a typical plasma membrane H(+)-ATPase-encoding gene, termed Lmpma1, thus leading to a twofold reduction in Lmpma1 expression. Since LmPMA1 is involved in intracellular pH homeostasis, we postulate that reduction in LmPMA1 activity disturbs the electrochemical transmembrane gradient in m210, thus leading to conidia defective in turgor pressure generation on leaf surface. Whole genome survey showed that L. maculans possesses a second plasma membrane H(+)-ATPase-encoding gene, termed Lmpma2. Silencing experiments, expression analyses and phylogenetic studies allowed us to highlight the essential role assumed by the Lmpma1 isoform in L.maculans pathogenicity.
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Remy E, Meyer M, Blaise F, Simon UK, Kuhn D, Chabirand M, Riquelme M, Balesdent MH, Rouxel T. The Lmgpi15 gene, encoding a component of the glycosylphosphatidylinositol anchor biosynthesis pathway, is required for morphogenesis and pathogenicity in Leptosphaeria maculans. THE NEW PHYTOLOGIST 2008; 179:1105-1120. [PMID: 18557818 DOI: 10.1111/j.1469-8137.2008.02522.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Random insertional mutagenesis was used to investigate pathogenicity determinants in Leptosphaeria maculans. One tagged nonpathogenic mutant, termed m20, was analysed in detail here. The mutant phenotype was investigated by microscopic analyses of infected plant tissues and in vitro growth assays. Complementation and silencing experiments were used to identify the altered gene. Its function was determined by bioinformatics analyses, cell biology experiments and functional studies. The mutant was blocked at the invasive growth phase after an unaffected initial penetration stage, and displayed a reduced growth rate and an aberrant hyphal morphology in vitro. The T-DNA insertion occurred in the intergenic region between two head-to-tail genes, leading to a complex deregulation of their expression. The unique gene accounting for the mutant phenotype was suggested to be the orthologue of the poorly conserved Saccharomyces cerevisiae gpi15, which encodes for one component of the glycosylphosphatidylinositol (GPI) anchor biosynthesis pathway. Consistent with this predicted function, a functional translational fusion with the green fluorescent protein (GFP) was targeted to the endoplasmic reticulum. Moreover, the mutant exhibited an altered cell wall and addition of glucosamine relieved growth defects. It is concluded that the GPI anchor biosynthetic pathway is required for morphogenesis, cell wall integrity and pathogenicity in Leptosphaeria maculans.
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Affiliation(s)
- Estelle Remy
- INRA, UMR 1290 BIOGER, Route de Saint-Cyr, F-78026 Versailles Cedex, France
| | - Michel Meyer
- INRA, UMR 1290 BIOGER, Route de Saint-Cyr, F-78026 Versailles Cedex, France
| | - Françoise Blaise
- INRA, UMR 1290 BIOGER, Route de Saint-Cyr, F-78026 Versailles Cedex, France
| | - Uwe K Simon
- Lehrstuhl Spezielle Botanik und Mykologie, Universität Tübingen, Auf der Morgenstelle 1, 72076 Tübingen, Germany
| | - Diana Kuhn
- Lehrstuhl Spezielle Botanik und Mykologie, Universität Tübingen, Auf der Morgenstelle 1, 72076 Tübingen, Germany
| | - Mélanie Chabirand
- INRA, UMR 1290 BIOGER, Route de Saint-Cyr, F-78026 Versailles Cedex, France
| | - Meritxell Riquelme
- Centro de Investigación Científica y de Educación Superior de Ensenada, Departamento de Microbiología, Edificio DBEA, Km. 107 Ctra. Tijuana-Ensenada, 22860 Ensenada, Baja California, Mexico
| | | | - Thierry Rouxel
- INRA, UMR 1290 BIOGER, Route de Saint-Cyr, F-78026 Versailles Cedex, France
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Kemppainen M, Duplessis S, Martin F, Pardo AG. T-DNA insertion, plasmid rescue and integration analysis in the model mycorrhizal fungus Laccaria bicolor. Microb Biotechnol 2008; 1:258-69. [PMID: 21261845 PMCID: PMC3815887 DOI: 10.1111/j.1751-7915.2008.00029.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Accepted: 01/24/2008] [Indexed: 12/04/2022] Open
Abstract
Ectomycorrhiza is a mutualistic symbiosis formed between fine roots of trees and the mycelium of soil fungi. This symbiosis plays a key role in forest ecosystems for the mineral nutrition of trees and the biology of the fungal communities associated. The characterization of genes involved in developmental and metabolic processes is important to understand the complex interactions that control the ectomycorrhizal symbiosis. Agrobacterium-mediated gene transfer (AMT) in fungi is currently opening a new era for fungal research. As whole genome sequences of several fungi are being released studies about T-DNA integration patterns are needed in order to understand the integration mechanisms involved and to evaluate the AMT as an insertional mutagenesis tool for different fungal species. The first genome sequence of a mycorrhizal fungus, the basidiomycete Laccaria bicolor, became public in July 2006. Release of Laccaria genome sequence and the availability of AMT makes this fungus an excellent model for functional genomic studies in ectomycorrhizal research. No data on the integration pattern in Laccaria genome were available, thus we optimized a plasmid rescue approach for this fungus. To this end the transformation vector (pHg/pBSk) was constructed allowing the rescue of the T-DNA right border (RB)-genomic DNA junctions in Escherichia coli. Fifty-one Agrobacterium-transformed fungal strains, picked up at random from a larger collection of T-DNA tagged strains (about 500), were analysed. Sixty-nine per cent were successfully rescued for the RB of which 87% were resolved for genomic integration sequences. Our results demonstrate that the plasmid rescue approach can be used for resolving T-DNA integration sites in Laccaria. The RB was well conserved during transformation of this fungus and the integration analysis showed no clear sequence homology between different genomic sites. Neither obvious sequence similarities were found between these sites and the T-DNA borders indicating non-homologous integration of the transgenes. Majority (75%) of the integrations were located in predicted genes. Agrobacterium-mediated gene transfer is a powerful tool that can be used for functional gene studies in Laccaria and will be helpful along with plasmid rescue in searching for relevant fungal genes involved in the symbiotic process.
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Affiliation(s)
- Minna Kemppainen
- Laboratorio de Micología Molecular, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes. Roque Sáenz Peña 352, (B1876BXD) Bernal, Provincia de Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Sebastien Duplessis
- UMR 1136 INRA‐Université Henri Poincaré Nancy 1, Interactions Arbres/Micro‐organismes, Centre INRA de‐Nancy, F‐54280 Champenoux, France
| | - Francis Martin
- UMR 1136 INRA‐Université Henri Poincaré Nancy 1, Interactions Arbres/Micro‐organismes, Centre INRA de‐Nancy, F‐54280 Champenoux, France
| | - Alejandro G. Pardo
- Laboratorio de Micología Molecular, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes. Roque Sáenz Peña 352, (B1876BXD) Bernal, Provincia de Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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Elliott CE, Howlett BJ. Mutation of a gene in the fungus Leptosphaeria maculans allows increased frequency of penetration of stomatal apertures of Arabidopsis thaliana. MOLECULAR PLANT 2008; 1:471-481. [PMID: 19825554 DOI: 10.1093/mp/ssn014] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Leptosphaeria maculans, a pathogen of Brassica napus, is unable to invade most wild-type accessions of Arabidopsis thaliana, although several mutants are susceptible. The infection pathway of L. maculans via a non-invasive inoculation method on A. thaliana lms1 (undefined), pmr4-1 (defective in callose deposition), and pen1-1 and pen2-1 (defective in non-host responses to several pathogens) mutants is described. On wild types Col-0 and Ler-0, hyphae are generally arrested at stomatal apertures. A T-DNA insertional mutant of L. maculans (A22) that penetrates stomatal apertures of Col-0 and Ler-0 five to seven times more often than the wild-type isolate is described. The higher penetration frequency of isolate A22 is associated with an increased hypersensitive response, which includes callose deposition. Complementation analysis showed that the phenotype of this isolate is due to T-DNA insertion in an intronless gene denoted as ipa (increased penetration on Arabidopsis). This gene is predicted to encode a protein of 702 amino acids with best matches to hypothetical proteins in other filamentous ascomycetes. The ipa gene is expressed in the wild-type isolate at low levels in culture and during infection of A. thaliana and B. napus.
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Affiliation(s)
- Candace E Elliott
- School of Botany, The University of Melbourne, Melbourne, Vic 3010, Australia
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24
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Fox EM, Gardiner DM, Keller NP, Howlett BJ. A Zn(II)2Cys6 DNA binding protein regulates the sirodesmin PL biosynthetic gene cluster in Leptosphaeria maculans. Fungal Genet Biol 2008; 45:671-82. [PMID: 18023597 PMCID: PMC2399893 DOI: 10.1016/j.fgb.2007.10.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2007] [Revised: 10/11/2007] [Accepted: 10/11/2007] [Indexed: 01/07/2023]
Abstract
A gene, sirZ, encoding a Zn(II)(2)Cys(6) DNA binding protein is present in a cluster of genes responsible for the biosynthesis of the epipolythiodioxopiperazine (ETP) toxin, sirodesmin PL in the ascomycete plant pathogen, Leptosphaeria maculans. RNA-mediated silencing of sirZ gives rise to transformants that produce only residual amounts of sirodesmin PL and display a decrease in the transcription of several sirodesmin PL biosynthetic genes. This indicates that SirZ is a major regulator of this gene cluster. Proteins similar to SirZ are encoded in the gliotoxin biosynthetic gene cluster of Aspergillus fumigatus (gliZ) and in an ETP-like cluster in Penicillium lilacinoechinulatum (PlgliZ). Despite its high level of sequence similarity to gliZ, PlgliZ is unable to complement the gliotoxin-deficiency of a mutant of gliZ in A. fumigatus. Putative binding sites for these regulatory proteins in the promoters of genes in these clusters were predicted using bioinformatic analysis. These sites are similar to those commonly bound by other proteins with Zn(II)(2)Cys(6) DNA binding domains.
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Affiliation(s)
- Ellen M. Fox
- School of Botany, The University of Melbourne, Vic, 3010 Australia, Corresponding author. Phone: +61 3 8344-5056 Fax: +61 3 9347-5460, E-mail address: (E. Fox)
| | | | - Nancy P. Keller
- Department of Plant Pathology, University of Wisconsin-Madison, Wisconsin, 53706 USA
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Biosynthetic gene clusters for epipolythiodioxopiperazines in filamentous fungi. ACTA ACUST UNITED AC 2008; 112:162-9. [DOI: 10.1016/j.mycres.2007.08.017] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 06/01/2007] [Accepted: 08/22/2007] [Indexed: 11/23/2022]
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Meng Y, Patel G, Heist M, Betts MF, Tucker SL, Galadima N, Donofrio NM, Brown D, Mitchell TK, Li L, Xu JR, Orbach M, Thon M, Dean RA, Farman ML. A systematic analysis of T-DNA insertion events in Magnaporthe oryzae. Fungal Genet Biol 2007; 44:1050-64. [PMID: 17544743 DOI: 10.1016/j.fgb.2007.04.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Revised: 03/19/2007] [Accepted: 04/04/2007] [Indexed: 01/24/2023]
Abstract
We describe here the analysis of random T-DNA insertions that were generated as part of a large-scale insertional mutagenesis project for Magnaporthe oryzae. Chromosomal regions flanking T-DNA insertions were rescued by inverse PCR, sequenced and used to search the M. oryzae genome assembly. Among the 175 insertions for which at least one flank was rescued, 137 had integrated in single-copy regions of the genome, 17 were in repeated sequences, one had no match to the genome, and the remainder were unassigned due to illegitimate T-DNA integration events. These included in order of abundance: head-to-tail tandem insertions, right border excision failures, left border excision failures and insertion of one T-DNA into another. The left borders of the T-DNA were frequently truncated and inserted in sequences with micro-homology to the left terminus. By contrast the right borders were less prone to degradation and appeared to have been integrated in a homology-independent manner. Gross genome rearrangements rarely occurred when the T-DNAs integrated in single-copy regions, although most insertions did cause small deletions at the target site. Significant insertion bias was detected, with promoters receiving two times more T-DNA hits than expected, and open reading frames receiving three times fewer. In addition, we found that the distribution of T-DNA inserts among the M. oryzae chromosomes was not random. The implications of these findings with regard to saturation mutagenesis of the M. oryzae genome are discussed.
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Affiliation(s)
- Yan Meng
- Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA
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Elliott CE, Gardiner DM, Thomas G, Cozijnsen A, VAN DE Wouw A, Howlett BJ. Production of the toxin sirodesmin PL by Leptosphaeria maculans during infection of Brassica napus. MOLECULAR PLANT PATHOLOGY 2007; 8:791-802. [PMID: 20507539 DOI: 10.1111/j.1364-3703.2007.00433.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
SUMMARY Sirodesmin PL is a non-host-selective phytotoxin produced by Leptosphaeria maculans, which causes blackleg disease of canola (Brassica napus). Previous studies have shown that sirodesmin PL biosynthesis involves a cluster of 18 co-regulated genes and that disruption of the two-module non-ribosomal peptide synthetase gene (sirP) in this cluster prevents the production of sirodesmin PL. Loss of sirodesmin PL did not affect the growth or fertility of the sirP mutant in vitro, but this mutant had less antibacterial and antifungal activity than the wild-type. When the sirP mutant was inoculated on to cotyledons of B. napus, it caused similar-sized lesions on cotyledons as the wild-type isolate, but subsequently caused fewer lesions and was half as effective as the wild-type in colonizing stems, as shown by quantitative PCR analyses. However, no significant difference was observed in size of lesions when either wild-type or mutant isolates were injected directly into the stem. The expression of two cluster genes, sirP and an ABC transporter, sirA, was studied in planta. Fungal isolates containing fusions of the green fluorescent protein gene with the promoters of these genes fluoresced after 10 days post-inoculation (dpi). Transcripts of sirP and sirA were detected after 11 dpi in cotyledons by reverse transcriptase PCR, and expression of both genes increased dramatically in stem tissue. This expression pattern was consistent with the distribution of sirodesmin PL in planta as revealed by mass spectrometry experiments.
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Affiliation(s)
- Candace E Elliott
- School of Botany, The University of Melbourne, Victoria 3010 Australia
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28
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Hane JK, Lowe RGT, Solomon PS, Tan KC, Schoch CL, Spatafora JW, Crous PW, Kodira C, Birren BW, Galagan JE, Torriani SFF, McDonald BA, Oliver RP. Dothideomycete plant interactions illuminated by genome sequencing and EST analysis of the wheat pathogen Stagonospora nodorum. THE PLANT CELL 2007; 19:3347-68. [PMID: 18024570 PMCID: PMC2174895 DOI: 10.1105/tpc.107.052829] [Citation(s) in RCA: 177] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Revised: 09/11/2007] [Accepted: 10/15/2007] [Indexed: 05/18/2023]
Abstract
Stagonospora nodorum is a major necrotrophic fungal pathogen of wheat (Triticum aestivum) and a member of the Dothideomycetes, a large fungal taxon that includes many important plant pathogens affecting all major crop plant families. Here, we report the acquisition and initial analysis of a draft genome sequence for this fungus. The assembly comprises 37,164,227 bp of nuclear DNA contained in 107 scaffolds. The circular mitochondrial genome comprises 49,761 bp encoding 46 genes, including four that are intron encoded. The nuclear genome assembly contains 26 classes of repetitive DNA, comprising 4.5% of the genome. Some of the repeats show evidence of repeat-induced point mutations consistent with a frequent sexual cycle. ESTs and gene prediction models support a minimum of 10,762 nuclear genes. Extensive orthology was found between the polyketide synthase family in S. nodorum and Cochliobolus heterostrophus, suggesting an ancient origin and conserved functions for these genes. A striking feature of the gene catalog was the large number of genes predicted to encode secreted proteins; the majority has no meaningful similarity to any other known genes. It is likely that genes for host-specific toxins, in addition to ToxA, will be found among this group. ESTs obtained from axenic mycelium grown on oleate (chosen to mimic early infection) and late-stage lesions sporulating on wheat leaves were obtained. Statistical analysis shows that transcripts encoding proteins involved in protein synthesis and in the production of extracellular proteases, cellulases, and xylanases predominate in the infection library. This suggests that the fungus is dependant on the degradation of wheat macromolecular constituents to provide the carbon skeletons and energy for the synthesis of proteins and other components destined for the developing pycnidiospores.
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MESH Headings
- Ascomycota/genetics
- DNA, Mitochondrial/genetics
- Expressed Sequence Tags
- Fungal Proteins/chemistry
- Fungal Proteins/genetics
- Gene Expression Regulation, Fungal
- Genes, Fungal
- Genome, Fungal/genetics
- Host-Parasite Interactions
- Multigene Family
- Phylogeny
- Protein Structure, Tertiary
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Transfer/genetics
- Repetitive Sequences, Nucleic Acid
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Triticum/microbiology
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Affiliation(s)
- James K Hane
- Australian Centre for Necrotrophic Fungal Pathogens, Murdoch University, WA 6150, Australia
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