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Ansari S, Aliasgharzad N, Sarikhani MR, Najafi N, Arzanlou M, Ölmez F. Nitrogen sources alter ligninase and cellulase activities of thermophilic fungi isolated from compost and vermicompost. Folia Microbiol (Praha) 2024; 69:323-332. [PMID: 37338677 DOI: 10.1007/s12223-023-01065-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 05/18/2023] [Indexed: 06/21/2023]
Abstract
Fungi harboring lignocellulolytic activity accelerate the composting process of agricultural wastes; however, using thermophilic fungal isolates for this process has been paid little attention. Moreover, exogenous nitrogen sources may differently affect fungal lignocellulolytic activity. A total of 250 thermophilic fungi were isolated from local compost and vermicompost samples. First, the isolates were qualitative assayed for ligninase and cellulase activities using Congo red (CR) and carboxymethyl cellulose (CMC) as substrates, respectively. Then, twenty superior isolates harboring higher ligninase and cellulase activities were selected and quantitatively assayed for both enzymes in basic mineral (BM) liquid medium supplemented with the relevant substrates and nitrogen sources including (NH4)2SO4 (AS), NH4NO3 (AN), urea (U), AS + U (1:1), or AN + U (1:1) with final nitrogen concentration of 0.3 g/L. The highest ligninase activities of 99.94, 89.82, 95.42, 96.25, and 98.34% of CR decolorization were recorded in isolates VC85, VC94, VC85, C145, and VC85 in the presence of AS, U, AS + U, AN, and AN + U, respectively. Mean ligninase activity of 63.75% in superior isolates was achieved in the presence of AS and ranked the highest among other N compounds. The isolates C200 and C184 exhibited the highest cellulolytic activity in the presence of AS and AN + U by 8.8 and 6.5 U/ml, respectively. Mean cellulase activity of 3.90 U/mL was achieved in AN + U and ranked the highest among other N compounds. Molecular identification of twenty superior isolates confirmed that all of them are belonging to Aspergillus fumigatus group. Focusing on the highest ligninase activity of the isolate VC85 in the presence of AS, the combination can be recommended as a potential bio-accelerator for compost production.
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Affiliation(s)
- Saeideh Ansari
- Department of Soil Science, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
| | - Nasser Aliasgharzad
- Department of Soil Science, Faculty of Agriculture, University of Tabriz, Tabriz, Iran.
| | | | - Nosratollah Najafi
- Department of Soil Science, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
| | - Mahdi Arzanlou
- Department of Plant Protection, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
| | - Fatih Ölmez
- Department of Plant Protection, Faculty of Agriculture, Sivas University of Science and Technology, Sivas, Turkey
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Abraham LN, Croll D. Genome-wide expression QTL mapping reveals the highly dynamic regulatory landscape of a major wheat pathogen. BMC Biol 2023; 21:263. [PMID: 37981685 PMCID: PMC10658818 DOI: 10.1186/s12915-023-01763-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 11/07/2023] [Indexed: 11/21/2023] Open
Abstract
BACKGROUND In agricultural ecosystems, outbreaks of diseases are frequent and pose a significant threat to food security. A successful pathogen undergoes a complex and well-timed sequence of regulatory changes to avoid detection by the host immune system; hence, well-tuned gene regulation is essential for survival. However, the extent to which the regulatory polymorphisms in a pathogen population provide an adaptive advantage is poorly understood. RESULTS We used Zymoseptoria tritici, one of the most important pathogens of wheat, to generate a genome-wide map of regulatory polymorphism governing gene expression. We investigated genome-wide transcription levels of 146 strains grown under nutrient starvation and performed expression quantitative trait loci (eQTL) mapping. We identified cis-eQTLs for 65.3% of all genes and the majority of all eQTL loci are within 2kb upstream and downstream of the transcription start site (TSS). We also show that polymorphism in different gene elements contributes disproportionally to gene expression variation. Investigating regulatory polymorphism in gene categories, we found an enrichment of regulatory variants for genes predicted to be important for fungal pathogenesis but with comparatively low effect size, suggesting a separate layer of gene regulation involving epigenetics. We also show that previously reported trait-associated SNPs in pathogen populations are frequently cis-regulatory variants of neighboring genes with implications for the trait architecture. CONCLUSIONS Overall, our study provides extensive evidence that single populations segregate large-scale regulatory variation and are likely to fuel rapid adaptation to resistant hosts and environmental change.
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Affiliation(s)
- Leen Nanchira Abraham
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, 2000, Neuchâtel, Switzerland
- Present address: Institute of Plant Sciences, University of Cologne, Cologne, Germany
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, 2000, Neuchâtel, Switzerland.
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Child HT, Deeks MJ, Rudd JJ, Bates S. Comparison of the impact of two key fungal signalling pathways on Zymoseptoria tritici infection reveals divergent contribution to invasive growth through distinct regulation of infection-associated genes. MOLECULAR PLANT PATHOLOGY 2023; 24:1220-1237. [PMID: 37306534 PMCID: PMC10502814 DOI: 10.1111/mpp.13365] [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: 03/17/2023] [Revised: 05/12/2023] [Accepted: 05/23/2023] [Indexed: 06/13/2023]
Abstract
The lifecycle of Zymoseptoria tritici requires a carefully regulated asymptomatic phase within the wheat leaf following penetration of the mesophyll via stomata. Here we compare the roles in this process of two key fungal signalling pathways, mutants of which were identified through forward genetics due to their avirulence on wheat. Whole-genome resequencing of avirulent Z. tritici T-DNA transformants identified disruptive mutations in ZtBCK1 from the kinase cascade of the cell wall integrity (CWI) pathway, and the adenylate cyclase gene ZtCYR1. Targeted deletion of these genes abolished the pathogenicity of the fungus and led to similar in vitro phenotypes to those associated with disruption of putative downstream kinases, both supporting previous studies and confirming the importance of these pathways in virulence. RNA sequencing was used to investigate the effect of ZtBCK1 and ZtCYR1 deletion on gene expression in both the pathogen and host during infection. ZtBCK1 was found to be required for the adaptation to the host environment, controlling expression of infection-associated secreted proteins, including known virulence factors. Meanwhile, ZtCYR1 is implicated in controlling the switch to necrotrophy, regulating expression of effectors associated with this transition. This represents the first study to compare the influence of CWI and cAMP signalling on in planta transcription of a fungal plant pathogen, providing insights into their differential regulation of candidate effectors during invasive growth.
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Affiliation(s)
| | | | - Jason J. Rudd
- Department of Protecting Crops and the EnvironmentRothamsted ResearchHarpendenUK
| | - Steven Bates
- Department of BiosciencesUniversity of ExeterExeterUK
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Sabnam N, Hussain A, Saha P. The secret password: Cell death-inducing proteins in filamentous phytopathogens - As versatile tools to develop disease-resistant crops. Microb Pathog 2023; 183:106276. [PMID: 37541554 DOI: 10.1016/j.micpath.2023.106276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 07/25/2023] [Accepted: 07/27/2023] [Indexed: 08/06/2023]
Abstract
Cell death-inducing proteins (CDIPs) are some of the secreted effector proteins manifested by filamentous oomycetes and fungal pathogens to invade the plant tissue and facilitate infection. Along with their involvement in different developmental processes and virulence, CDIPs play a crucial role in plant-pathogen interactions. As the name implies, CDIPs cause necrosis and trigger localised cell death in the infected host tissues by the accumulation of higher concentrations of hydrogen peroxide (H2O2), oxidative burst, accumulation of nitric oxide (NO), and electrolyte leakage. They also stimulate the biosynthesis of defense-related phytohormones such as salicylic acid (SA), jasmonic acid (JA), abscisic acid (ABA), and ethylene (ET), as well as the expression of pathogenesis-related (PR) genes that are important in disease resistance. Altogether, the interactions result in the hypersensitive response (HR) in the host plant, which might confer systemic acquired resistance (SAR) in some cases against a vast array of related and unrelated pathogens. The CDIPs, due to their capability of inducing host resistance, are thus unique among the array of proteins secreted by filamentous plant pathogens. More interestingly, a few transgenic plant lines have also been developed expressing the CDIPs with added resistance. Thus, CDIPs have opened an interesting hot area of research. The present study critically reviews the current knowledge of major types of CDIPs identified across filamentous phytopathogens and their modes of action in the last couple of years. This review also highlights the recent breakthrough technologies in studying plant-pathogen interactions as well as crop improvement by enhancing disease resistance through CDIPs.
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Affiliation(s)
- Nazmiara Sabnam
- Department of Life Sciences, Presidency University, Kolkata, India.
| | - Afzal Hussain
- Department of Bioinformatics, Maulana Azad National Institute of Technology, Bhopal, India
| | - Pallabi Saha
- Biotechnology Institute, University of Minnesota, Saint Paul, Minnesota, 55108, United States; Department of Biotechnology, National Institute of Technology, Durgapur, India
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Chen H, King R, Smith D, Bayon C, Ashfield T, Torriani S, Kanyuka K, Hammond-Kosack K, Bieri S, Rudd J. Combined pangenomics and transcriptomics reveals core and redundant virulence processes in a rapidly evolving fungal plant pathogen. BMC Biol 2023; 21:24. [PMID: 36747219 PMCID: PMC9903594 DOI: 10.1186/s12915-023-01520-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 01/19/2023] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Studying genomic variation in rapidly evolving pathogens potentially enables identification of genes supporting their "core biology", being present, functional and expressed by all strains or "flexible biology", varying between strains. Genes supporting flexible biology may be considered to be "accessory", whilst the "core" gene set is likely to be important for common features of a pathogen species biology, including virulence on all host genotypes. The wheat-pathogenic fungus Zymoseptoria tritici represents one of the most rapidly evolving threats to global food security and was the focus of this study. RESULTS We constructed a pangenome of 18 European field isolates, with 12 also subjected to RNAseq transcription profiling during infection. Combining this data, we predicted a "core" gene set comprising 9807 sequences which were (1) present in all isolates, (2) lacking inactivating polymorphisms and (3) expressed by all isolates. A large accessory genome, consisting of 45% of the total genes, was also defined. We classified genetic and genomic polymorphism at both chromosomal and individual gene scales. Proteins required for essential functions including virulence had lower-than average sequence variability amongst core genes. Both core and accessory genomes encoded many small, secreted candidate effector proteins that likely interact with plant immunity. Viral vector-mediated transient in planta overexpression of 88 candidates failed to identify any which induced leaf necrosis characteristic of disease. However, functional complementation of a non-pathogenic deletion mutant lacking five core genes demonstrated that full virulence was restored by re-introduction of the single gene exhibiting least sequence polymorphism and highest expression. CONCLUSIONS These data support the combined use of pangenomics and transcriptomics for defining genes which represent core, and potentially exploitable, weaknesses in rapidly evolving pathogens.
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Affiliation(s)
- Hongxin Chen
- grid.418374.d0000 0001 2227 9389Department of Protecting Crops and the Environment, Rothamsted Research, Harpenden, Herts UK ,grid.12981.330000 0001 2360 039XPresent address: School of Agriculture, Shenzhen Campus of Sun Yat-sen University, Guangming District, Shenzhen, Guangdong People’s Republic of China
| | - Robert King
- grid.418374.d0000 0001 2227 9389Department of Protecting Crops and the Environment, Rothamsted Research, Harpenden, Herts UK
| | - Dan Smith
- grid.418374.d0000 0001 2227 9389Department of Protecting Crops and the Environment, Rothamsted Research, Harpenden, Herts UK
| | - Carlos Bayon
- grid.418374.d0000 0001 2227 9389Department of Protecting Crops and the Environment, Rothamsted Research, Harpenden, Herts UK
| | - Tom Ashfield
- grid.418374.d0000 0001 2227 9389Department of Protecting Crops and the Environment, Rothamsted Research, Harpenden, Herts UK ,grid.418374.d0000 0001 2227 9389Crop Health and Protection (CHaP), Rothamsted Research, Harpenden, Herts UK
| | - Stefano Torriani
- grid.420222.40000 0001 0669 0426Syngenta Crop Protection AG, Schaffhauserstrasse 101, CH-4332 Stein, Switzerland
| | - Kostya Kanyuka
- grid.418374.d0000 0001 2227 9389Department of Protecting Crops and the Environment, Rothamsted Research, Harpenden, Herts UK ,grid.17595.3f0000 0004 0383 6532Present address: National Institute for Agricultural Botany (NIAB), 93 Lawrence Weaver Road, Cambridge, UK
| | - Kim Hammond-Kosack
- grid.418374.d0000 0001 2227 9389Department of Protecting Crops and the Environment, Rothamsted Research, Harpenden, Herts UK
| | - Stephane Bieri
- grid.420222.40000 0001 0669 0426Syngenta Crop Protection AG, Schaffhauserstrasse 101, CH-4332 Stein, Switzerland
| | - Jason Rudd
- Department of Protecting Crops and the Environment, Rothamsted Research, Harpenden, Herts, UK.
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Blyth HR, Smith D, King R, Bayon C, Ashfield T, Walpole H, Venter E, Ray RV, Kanyuka K, Rudd JJ. Fungal plant pathogen "mutagenomics" reveals tagged and untagged mutations in Zymoseptoria tritici and identifies SSK2 as key morphogenesis and stress-responsive virulence factor. FRONTIERS IN PLANT SCIENCE 2023; 14:1140824. [PMID: 37206970 PMCID: PMC10190600 DOI: 10.3389/fpls.2023.1140824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/29/2023] [Indexed: 05/21/2023]
Abstract
"Mutagenomics" is the combination of random mutagenesis, phenotypic screening, and whole-genome re-sequencing to uncover all tagged and untagged mutations linked with phenotypic changes in an organism. In this study, we performed a mutagenomics screen on the wheat pathogenic fungus Zymoseptoria tritici for altered morphogenetic switching and stress sensitivity phenotypes using Agrobacterium-mediated "random" T-DNA mutagenesis (ATMT). Biological screening identified four mutants which were strongly reduced in virulence on wheat. Whole genome re-sequencing defined the positions of the T-DNA insertion events and revealed several unlinked mutations potentially affecting gene functions. Remarkably, two independent reduced virulence mutant strains, with similarly altered stress sensitivities and aberrant hyphal growth phenotypes, were found to have a distinct loss of function mutations in the ZtSSK2 MAPKKK gene. One mutant strain had a direct T-DNA insertion affecting the predicted protein's N-terminus, while the other possessed an unlinked frameshift mutation towards the C-terminus. We used genetic complementation to restore both strains' wild-type (WT) function (virulence, morphogenesis, and stress response). We demonstrated that ZtSSK2 has a non-redundant function with ZtSTE11 in virulence through the biochemical activation of the stress-activated HOG1 MAPK pathway. Moreover, we present data suggesting that SSK2 has a unique role in activating this pathway in response to specific stresses. Finally, dual RNAseq-based transcriptome profiling of WT and SSK2 mutant strains revealed many HOG1-dependent transcriptional changes in the fungus during early infection and suggested that the host response does not discriminate between WT and mutant strains during this early phase. Together these data define new genes implicated in the virulence of the pathogen and emphasise the importance of a whole genome sequencing step in mutagenomic discovery pipelines.
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Affiliation(s)
- Hannah R. Blyth
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
| | - Dan Smith
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
| | - Robert King
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
| | - Carlos Bayon
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
| | - Tom Ashfield
- Crop Health and Protection (CHAP), Rothamsted Research, Harpenden, United Kingdom
| | - Hannah Walpole
- Bioimaging Unit, Rothamsted Research, Harpenden, United Kingdom
| | - Eudri Venter
- Bioimaging Unit, Rothamsted Research, Harpenden, United Kingdom
| | - Rumiana V. Ray
- Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Loughborough, United Kingdom
| | - Kostya Kanyuka
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
| | - Jason J. Rudd
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
- *Correspondence: Jason J. Rudd,
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7
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Dal’Sasso TCS, Rody HVS, Oliveira LO. Genome-Wide Analysis and Evolutionary History of the Necrosis- and Ethylene-Inducing Peptide 1-Like Protein (NLP) Superfamily Across the Dothideomycetes Class of Fungi. Curr Microbiol 2023; 80:44. [DOI: 10.1007/s00284-022-03125-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 11/15/2022] [Indexed: 12/24/2022]
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8
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Xiang J, Cheng J, Wei L, Li M, Wu J. Functional analysis of the Nep1-like proteins from Plasmopara viticola. PLANT SIGNALING & BEHAVIOR 2022; 17:2000791. [PMID: 35152834 PMCID: PMC9176246 DOI: 10.1080/15592324.2021.2000791] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 06/14/2023]
Abstract
Necrosis and ethylene-inducing peptide 1 (Nep1) -like proteins (NLP) are secreted by multiple taxonomically unrelated plant pathogens (bacteria, fungi, and oomycete) and are best known for inducing cell death and immune responses in dicotyledonous plants. A group of putative NLP genes from obligate biotrophic oomycete Plasmopara viticola were predicted by RNA-Seq in our previous study, but their activity has not been established. Therefore, we analyzed the P. viticola NLP (PvNLP) family and identified seven PvNLP genes. They all belong to type 1 NLP genes and form a P. viticola-specific cluster when compared with other pathogen NLP genes. The expression of PvNLPs was induced during early infection process and the expression patterns could be categorized into two groups. Agrobacterium tumefaciens-mediated transient expression assays revealed that only PvNLP7 was cytotoxic and could induce Phytophthora capsici resistance in Nicotiana benthamiana. Functional analysis showed that PvNLP4, PvNLP5, PvNLP7, and PvNLP10 significantly improved disease resistance of Arabidopsis thaliana to Hyaloperonospora arabidopsidis. Moreover, the four genes caused an inhibition of plant growth which is typically associated with enhanced immunity when over-expressed in Arabidopsis. Further research found that PvNLP7 could activate the expression of defense-related genes and its conserved NPP1 domain was critical for cell death- and immunity-inducing activity. This record of NLP genes from P. viticola showed a functional diversification, laying a foundation for further study on pathogenic mechanism of the devastating pathogen.
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Affiliation(s)
- Jiang Xiang
- Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Jianhui Cheng
- Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Lingzhu Wei
- Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Mingshan Li
- Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Jiang Wu
- Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
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Distinct roles for different autophagy-associated genes in the virulence of the fungal wheat pathogen Zymoseptoria tritici. Fungal Genet Biol 2022; 163:103748. [PMID: 36309095 DOI: 10.1016/j.fgb.2022.103748] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 09/16/2022] [Accepted: 10/13/2022] [Indexed: 01/06/2023]
Abstract
The fungal wheat pathogen Zymoseptoria tritici causes major crop losses as the causal agent of the disease Septoria tritici blotch. The infection cycle of Z. tritici displays two distinct phases, beginning with an extended symptomless phase of 1-2 weeks, before the fungus induces host cell death and tissue collapse in the leaf. Recent evidence suggests that the fungus uses little host-derived nutrition during asymptomatic colonisation, raising questions as to the sources of energy required for this initial growth phase. Autophagy is crucial for the pathogenicity of other fungal plant pathogens through its roles in supporting cellular differentiation and growth under starvation. Here we characterised the contributions of the autophagy genes ZtATG1 and ZtATG8 to the development and virulence of Z. tritici. Deletion of ZtATG1 led to inhibition of autophagy but had no impact on starvation-induced hyphal differentiation or virulence, suggesting that autophagy is not required for Z. tritici pathogenicity. Contrastingly, ZtATG8 deletion delayed the transition to necrotrophic growth, despite having no influence on filamentous growth under starvation, pointing to an autophagy-independent role of ZtATG8 during Z. tritici infection. To our knowledge, this study represents the first to find autophagy not to contribute to the virulence of a fungal plant pathogen, and reveals novel roles for different autophagy-associated proteins in Z. tritici.
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Kilaru S, Fantozzi E, Cannon S, Schuster M, Chaloner TM, Guiu-Aragones C, Gurr SJ, Steinberg G. Zymoseptoria tritici white-collar complex integrates light, temperature and plant cues to initiate dimorphism and pathogenesis. Nat Commun 2022; 13:5625. [PMID: 36163135 PMCID: PMC9512790 DOI: 10.1038/s41467-022-33183-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 09/07/2022] [Indexed: 11/08/2022] Open
Abstract
Transitioning from spores to hyphae is pivotal to host invasion by the plant pathogenic fungus Zymoseptoria tritici. This dimorphic switch can be initiated by high temperature in vitro (~27 °C); however, such a condition may induce cellular heat stress, questioning its relevance to field infections. Here, we study the regulation of the dimorphic switch by temperature and other factors. Climate data from wheat-growing areas indicate that the pathogen sporadically experiences high temperatures such as 27 °C during summer months. However, using a fluorescent dimorphic switch reporter (FDR1) in four wild-type strains, we show that dimorphic switching already initiates at 15-18 °C, and is enhanced by wheat leaf surface compounds. Transcriptomics reveals 1261 genes that are up- or down-regulated in hyphae of all strains. These pan-strain core dimorphism genes (PCDGs) encode known effectors, dimorphism and transcription factors, and light-responsive proteins (velvet factors, opsins, putative blue light receptors). An FDR1-based genetic screen reveals a crucial role for the white-collar complex (WCC) in dimorphism and virulence, mediated by control of PCDG expression. Thus, WCC integrates light with biotic and abiotic cues to orchestrate Z. tritici infection.
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Affiliation(s)
- Sreedhar Kilaru
- Biosciences, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Elena Fantozzi
- Biosciences, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Stuart Cannon
- Biosciences, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Martin Schuster
- Biosciences, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Thomas M Chaloner
- Biosciences, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | | | - Sarah J Gurr
- Biosciences, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
- University of Utrecht, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Gero Steinberg
- Biosciences, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK.
- University of Utrecht, Padualaan 8, Utrecht, 3584 CH, The Netherlands.
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11
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The necrosis-inducing protein (NIP) gene contributes to Penicillium expansum virulence during postharvest pear infection. Food Res Int 2022; 158:111562. [DOI: 10.1016/j.foodres.2022.111562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 06/18/2022] [Accepted: 06/21/2022] [Indexed: 11/17/2022]
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12
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Khairi MHF, Nor Muhammad NA, Bunawan H, Abdul Murad AM, Ramzi AB. Unveiling the Core Effector Proteins of Oil Palm Pathogen Ganoderma boninense via Pan-Secretome Analysis. J Fungi (Basel) 2022; 8:jof8080793. [PMID: 36012782 PMCID: PMC9409662 DOI: 10.3390/jof8080793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 07/04/2022] [Accepted: 07/12/2022] [Indexed: 12/10/2022] Open
Abstract
Ganoderma boninense is the major causal agent of basal stem rot (BSR) disease in oil palm, causing the progressive rot of the basal part of the stem. Despite its prominence, the key pathogenicity determinants for the aggressive nature of hemibiotrophic infection remain unknown. In this study, genome sequencing and the annotation of G. boninense T10 were carried out using the Illumina sequencing platform, and comparative genome analysis was performed with previously reported G. boninense strains (NJ3 and G3). The pan-secretome of G. boninense was constructed and comprised 937 core orthogroups, 243 accessory orthogroups, and 84 strain-specific orthogroups. In total, 320 core orthogroups were enriched with candidate effector proteins (CEPs) that could be classified as carbohydrate-active enzymes, hydrolases, and non-catalytic proteins. Differential expression analysis revealed an upregulation of five CEP genes that was linked to the suppression of PTI signaling cascade, while the downregulation of four CEP genes was linked to the inhibition of PTI by preventing host defense elicitation. Genome architecture analysis revealed the one-speed architecture of the G. boninense genome and the lack of preferential association of CEP genes to transposable elements. The findings obtained from this study aid in the characterization of pathogenicity determinants and molecular biomarkers of BSR disease.
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Affiliation(s)
- Mohamad Hazwan Fikri Khairi
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia; (M.H.F.K.); (N.A.N.M.); (H.B.)
| | - Nor Azlan Nor Muhammad
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia; (M.H.F.K.); (N.A.N.M.); (H.B.)
| | - Hamidun Bunawan
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia; (M.H.F.K.); (N.A.N.M.); (H.B.)
| | - Abdul Munir Abdul Murad
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia;
| | - Ahmad Bazli Ramzi
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia; (M.H.F.K.); (N.A.N.M.); (H.B.)
- Correspondence: ; Tel.: +603-8921-4546; Fax: +603-8921-3398
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Yang G, Yang J, Zhang Q, Wang W, Feng L, Zhao L, An B, Wang Q, He C, Luo H. The Effector Protein CgNLP1 of Colletotrichum gloeosporioides Affects Invasion and Disrupts Nuclear Localization of Necrosis-Induced Transcription Factor HbMYB8-Like to Suppress Plant Defense Signaling. Front Microbiol 2022; 13:911479. [PMID: 35770165 PMCID: PMC9234567 DOI: 10.3389/fmicb.2022.911479] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 05/13/2022] [Indexed: 11/13/2022] Open
Abstract
Fungi secrete numerous effectors to modulate host defense systems. Understanding the molecular mechanisms by which fungal effectors regulate plant defense is of great importance for the development of novel strategies for disease control. In this study, we identified necrosis- and ethylene-inducing protein 1 (Nep1)-like protein (NLP) effector gene, CgNLP1, which contributed to conidial germination, appressorium formation, invasive growth, and virulence of Colletotrichum gloeosporioides to the rubber tree. Transient expression of CgNLP1 in the leaves of Nicotiana benthamiana induced ethylene production in plants. Ectopic expression of CgNLP1 in Arabidopsis significantly enhanced the resistance to Botrytis cinerea and Alternaria brassicicola. An R2R3 type transcription factor HbMYB8-like of rubber tree was identified as the target of CgNLP1.HbMYB8-like, localized on the nucleus, and induced cell death in N. benthamiana. CgNLP1 disrupted nuclear accumulation of HbMYB8-like and suppressed HbMYB8-like induced cell death, which is mediated by the salicylic acid (SA) signal pathway. This study suggested a new strategy whereby C. gloeosporioides exploited the CgNLP1 effector to affect invasion and suppress a host defense regulator HbMYB8-like to facilitate infection.
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Affiliation(s)
- Guangyong Yang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Tropical Corps, Hainan University, Haikou, China
- Hainan Yazhou Bay Seed Laboratory, Sanya Nanfan Research Institute of Hainan University, Sanya, China
| | - Jie Yang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Tropical Corps, Hainan University, Haikou, China
- Hainan Yazhou Bay Seed Laboratory, Sanya Nanfan Research Institute of Hainan University, Sanya, China
| | - Qiwei Zhang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Tropical Corps, Hainan University, Haikou, China
- Hainan Yazhou Bay Seed Laboratory, Sanya Nanfan Research Institute of Hainan University, Sanya, China
| | - Wenfeng Wang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Tropical Corps, Hainan University, Haikou, China
| | - Liping Feng
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Tropical Corps, Hainan University, Haikou, China
| | - Li Zhao
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Tropical Corps, Hainan University, Haikou, China
| | - Bang An
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Tropical Corps, Hainan University, Haikou, China
- Hainan Yazhou Bay Seed Laboratory, Sanya Nanfan Research Institute of Hainan University, Sanya, China
| | - Qiannan Wang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Tropical Corps, Hainan University, Haikou, China
- Hainan Yazhou Bay Seed Laboratory, Sanya Nanfan Research Institute of Hainan University, Sanya, China
| | - Chaozu He
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Tropical Corps, Hainan University, Haikou, China
- Hainan Yazhou Bay Seed Laboratory, Sanya Nanfan Research Institute of Hainan University, Sanya, China
| | - Hongli Luo
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Tropical Corps, Hainan University, Haikou, China
- Hainan Yazhou Bay Seed Laboratory, Sanya Nanfan Research Institute of Hainan University, Sanya, China
- *Correspondence: Hongli Luo
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14
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Prediction of effector proteins and their implications in pathogenicity of phytopathogenic filamentous fungi: A review. Int J Biol Macromol 2022; 206:188-202. [PMID: 35227707 DOI: 10.1016/j.ijbiomac.2022.02.133] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 02/11/2022] [Accepted: 02/22/2022] [Indexed: 12/14/2022]
Abstract
Plant pathogenic fungi encode and secrete effector proteins to promote pathogenesis. In recent years, the important role of effector proteins in fungi and plant host interactions has become increasingly prominent. In this review, the functional characterization and molecular mechanisms by which fungal effector proteins modulate biological processes and suppress the defense of plant hosts are discussed, with an emphasis on cell localization during fungal infection. This paper also provides a comprehensive review of bioinformatic and experimental methods that are currently available for the identification of fungal effector proteins. We additionally summarize the secretion pathways and the methods for verifying the presence effector proteins in plant host cells. For future research, comparative genomic studies of different pathogens with varying life cycles will allow comprehensive and systematic identification of effector proteins. Additionally, functional analysis of effector protein interactions with a wider range of hosts (especially non-model crops) will provide more detailed repertoires of fungal effectors. Identifying effector proteins and verifying their functions will improve our understanding of their role in causing disease and in turn guide future strategies for combatting fungal infections.
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15
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Chen JB, Bao SW, Fang YL, Wei LY, Zhu WS, Peng YL, Fan J. An LRR-only protein promotes NLP-triggered cell death and disease susceptibility by facilitating oligomerization of NLP in Arabidopsis. THE NEW PHYTOLOGIST 2021; 232:1808-1822. [PMID: 34403491 DOI: 10.1111/nph.17680] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Necrosis- and ethylene-inducing peptide 1 (Nep1)-like proteins (NLPs) constitute a superfamily of proteins toxic to dicot plants, but the molecular basis of this toxicity remains obscure. Using quantitative trait locus (QTL) analysis we investigated the genetic variation underlying ion leakage in Arabidopsis plants elicited with MoNLP1 derived from Magnaporthe oryzae. The QTL conditioning MoNLP1 toxicity was positionally cloned and further characterized to elucidate its mode of action. MoNLP1-triggered cell death varied significantly across > 250 Arabidopsis accessions and three QTLs were identified conferring the observed variation. The QTL on chromosome 4 was uncovered to encode a leucine-rich repeat (LRR)-only protein designated as NTCD4, which shares high sequence identity with a set of nucleotide-binding LRR proteins. NTCD4 was secreted into the apoplast and physically interacted with multiple NLPs. Apoplastic NTCD4 facilitated the oligomerization of NLP, which was closely associated with toxicity in planta. The natural genetic variation causing D3N change in NTCD4 reduced the secretion efficiency of NTCD4 and the infection of Botrytis cinerea on Arabidopsis plants. These observations demonstrate that the plant-derived NTCD4 is recruited by NLPs to promote toxicity via facilitating their oligomerization, which extends our understanding of a key step in the toxic mode of action of NLPs.
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Affiliation(s)
- Jun-Bin Chen
- Department of Plant Pathology, MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193, Beijing, China
| | - Shu-Wen Bao
- Department of Plant Pathology, MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193, Beijing, China
| | - Ya-Li Fang
- Department of Plant Pathology, MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193, Beijing, China
| | - Lu-Yang Wei
- Department of Plant Pathology, MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193, Beijing, China
| | - Wang-Sheng Zhu
- Department of Plant Pathology, MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193, Beijing, China
| | - You-Liang Peng
- Department of Plant Pathology, MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193, Beijing, China
- State Key Laboratory of Agrobiotechnology, China Agricultural University, 100193, Beijing, China
| | - Jun Fan
- Department of Plant Pathology, MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193, Beijing, China
- Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, China Agricultural University, 100193, Beijing, China
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16
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Duhan D, Gajbhiye S, Jaswal R, Singh RP, Sharma TR, Rajarammohan S. Functional Characterization of the Nep1-Like Protein Effectors of the Necrotrophic Pathogen - Alternaria brassicae. Front Microbiol 2021; 12:738617. [PMID: 34764943 PMCID: PMC8576325 DOI: 10.3389/fmicb.2021.738617] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 09/29/2021] [Indexed: 11/23/2022] Open
Abstract
Alternaria brassicae is an important necrotrophic pathogen that infects the Brassicaceae family. A. brassicae, like other necrotrophs, also secretes various proteinaceous effectors and metabolites that cause cell death to establish itself in the host. However, there has been no systematic study of A. brassicae effectors and their roles in pathogenesis. The availability of the genome sequence of A. brassicae in public domain has enabled the search for effectors and their functional characterization. Nep1-like proteins (NLPs) are a superfamily of proteins that induce necrosis and ethylene biosynthesis. They have been reported from a variety of microbes including bacteria, fungi, and oomycetes. In this study, we identified two NLPs from A. brassicae viz. AbrNLP1 and AbrNLP2 and functionally characterized them. Although both AbrNLPs were found to be secretory in nature, they localized differentially inside the plant. AbrNLP2 was found to induce necrosis in both host and non-host species, while AbrNLP1 could not induce necrosis in both species. Additionally, AbrNLP2 was shown to induce pathogen-associated molecular pattern (PAMP)-triggered immunity in both host and non-host species. Overall, our study indicates that AbrNLPs are functionally and spatially (subcellular location) distinct and may play different but important roles during the pathogenesis of A. brassicae.
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Affiliation(s)
- Deepak Duhan
- Agricultural Biotechnology Division, National Agri-Food Biotechnology Institute, Mohali, India
| | - Shivani Gajbhiye
- Agricultural Biotechnology Division, National Agri-Food Biotechnology Institute, Mohali, India
| | - Rajdeep Jaswal
- Agricultural Biotechnology Division, National Agri-Food Biotechnology Institute, Mohali, India
| | - Ravindra Pal Singh
- Nutritional Biotechnology Division, National Agri-Food Biotechnology Institute, Mohali, India
| | - Tilak Raj Sharma
- Indian Council of Agricultural Research, Division of Crop Science, Krishi Bhavan, New Delhi, India
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17
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Machado Wood AK, Panwar V, Grimwade-Mann M, Ashfield T, Hammond-Kosack KE, Kanyuka K. The vesicular trafficking system component MIN7 is required for minimizing Fusarium graminearum infection. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:5010-5023. [PMID: 33877328 PMCID: PMC8364293 DOI: 10.1093/jxb/erab170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 04/15/2021] [Indexed: 05/13/2023]
Abstract
Plants have developed intricate defense mechanisms, referred to as innate immunity, to defend themselves against a wide range of pathogens. Plants often respond rapidly to pathogen attack by the synthesis and delivery to the primary infection sites of various antimicrobial compounds, proteins, and small RNA in membrane vesicles. Much of the evidence regarding the importance of vesicular trafficking in plant-pathogen interactions comes from studies involving model plants whereas this process is relatively understudied in crop plants. Here we assessed whether the vesicular trafficking system components previously implicated in immunity in Arabidopsis play a role in the interaction with Fusarium graminearum, a fungal pathogen well-known for its ability to cause Fusarium head blight disease in wheat. Among the analysed vesicular trafficking mutants, two independent T-DNA insertion mutants in the AtMin7 gene displayed a markedly enhanced susceptibility to F. graminearum. Earlier studies identified this gene, encoding an ARF-GEF protein, as a target for the HopM1 effector of the bacterial pathogen Pseudomonas syringae pv. tomato, which destabilizes MIN7 leading to its degradation and weakening host defenses. To test whether this key vesicular trafficking component may also contribute to defense in crop plants, we identified the candidate TaMin7 genes in wheat and knocked-down their expression through virus-induced gene silencing. Wheat plants in which TaMin7 genes were silenced displayed significantly more Fusarium head blight disease. This suggests that disruption of MIN7 function in both model and crop plants compromises the trafficking of innate immunity signals or products resulting in hypersusceptibility to various pathogens.
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Affiliation(s)
- Ana K Machado Wood
- Biointeractions and Crop Protection, Rothamsted Research, Harpenden AL5 2JQ, UK
| | - Vinay Panwar
- Biointeractions and Crop Protection, Rothamsted Research, Harpenden AL5 2JQ, UK
| | - Mike Grimwade-Mann
- Biointeractions and Crop Protection, Rothamsted Research, Harpenden AL5 2JQ, UK
| | - Tom Ashfield
- Biointeractions and Crop Protection, Rothamsted Research, Harpenden AL5 2JQ, UK
- Crop Health and Protection (CHAP), Rothamsted Research, Harpenden AL5 2JQ, UK
| | | | - Kostya Kanyuka
- Biointeractions and Crop Protection, Rothamsted Research, Harpenden AL5 2JQ, UK
- Correspondence:
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18
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Ebert MK, Rangel LI, Spanner RE, Taliadoros D, Wang X, Friesen TL, de Jonge R, Neubauer JD, Secor GA, Thomma BPHJ, Stukenbrock EH, Bolton MD. Identification and characterization of Cercospora beticola necrosis-inducing effector CbNip1. MOLECULAR PLANT PATHOLOGY 2021; 22:301-316. [PMID: 33369055 PMCID: PMC7865086 DOI: 10.1111/mpp.13026] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 11/08/2020] [Accepted: 11/09/2020] [Indexed: 05/30/2023]
Abstract
Cercospora beticola is a hemibiotrophic fungus that causes cercospora leaf spot disease of sugar beet (Beta vulgaris). After an initial symptomless biotrophic phase of colonization, necrotic lesions appear on host leaves as the fungus switches to a necrotrophic lifestyle. The phytotoxic secondary metabolite cercosporin has been shown to facilitate fungal virulence for several Cercospora spp. However, because cercosporin production and subsequent cercosporin-initiated formation of reactive oxygen species is light-dependent, cell death evocation by this toxin is only fully ensured during a period of light. Here, we report the discovery of the effector protein CbNip1 secreted by C. beticola that causes enhanced necrosis in the absence of light and, therefore, may complement light-dependent necrosis formation by cercosporin. Infiltration of CbNip1 protein into sugar beet leaves revealed that darkness is essential for full CbNip1-triggered necrosis, as light exposure delayed CbNip1-triggered host cell death. Gene expression analysis during host infection shows that CbNip1 expression is correlated with symptom development in planta. Targeted gene replacement of CbNip1 leads to a significant reduction in virulence, indicating the importance of CbNip1 during colonization. Analysis of 89 C. beticola genomes revealed that CbNip1 resides in a region that recently underwent a selective sweep, suggesting selection pressure exists to maintain a beneficial variant of the gene. Taken together, CbNip1 is a crucial effector during the C. beticola-sugar beet disease process.
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Affiliation(s)
- Malaika K. Ebert
- Edward T. Schafer Agricultural Research CenterUSDA Agricultural Research ServiceFargoNorth DakotaUSA
- Department of Plant PathologyNorth Dakota State UniversityFargoNorth DakotaUSA
- Laboratory of PhytopathologyWageningen UniversityWageningenNetherlands
- Present address:
Department of Plant BiologyMichigan State UniversityEast LansingMichiganUSA
| | - Lorena I. Rangel
- Edward T. Schafer Agricultural Research CenterUSDA Agricultural Research ServiceFargoNorth DakotaUSA
| | - Rebecca E. Spanner
- Edward T. Schafer Agricultural Research CenterUSDA Agricultural Research ServiceFargoNorth DakotaUSA
- Department of Plant PathologyNorth Dakota State UniversityFargoNorth DakotaUSA
| | - Demetris Taliadoros
- Environmental Genomics GroupMax Planck Institute for Evolutionary BiologyPlönGermany
- Christian‐Albrechts University of KielKielGermany
| | - Xiaoyun Wang
- Edward T. Schafer Agricultural Research CenterUSDA Agricultural Research ServiceFargoNorth DakotaUSA
- Present address:
Institute of BiotechnologyCornell UniversityIthacaNew YorkUSA
| | - Timothy L. Friesen
- Edward T. Schafer Agricultural Research CenterUSDA Agricultural Research ServiceFargoNorth DakotaUSA
- Department of Plant PathologyNorth Dakota State UniversityFargoNorth DakotaUSA
| | - Ronnie de Jonge
- Plant‐Microbe InteractionsDepartment of BiologyUtrecht UniversityUtrechtNetherlands
- Department of Plant Systems BiologyVIBGhentBelgium
- Department of Plant Biotechnology and BioinformaticsGhent UniversityGhentBelgium
| | - Jonathan D. Neubauer
- Edward T. Schafer Agricultural Research CenterUSDA Agricultural Research ServiceFargoNorth DakotaUSA
| | - Gary A. Secor
- Department of Plant PathologyNorth Dakota State UniversityFargoNorth DakotaUSA
| | - Bart P. H. J. Thomma
- Laboratory of PhytopathologyWageningen UniversityWageningenNetherlands
- University of Cologne, Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS)CologneGermany
| | - Eva H. Stukenbrock
- Environmental Genomics GroupMax Planck Institute for Evolutionary BiologyPlönGermany
- Christian‐Albrechts University of KielKielGermany
| | - Melvin D. Bolton
- Edward T. Schafer Agricultural Research CenterUSDA Agricultural Research ServiceFargoNorth DakotaUSA
- Department of Plant PathologyNorth Dakota State UniversityFargoNorth DakotaUSA
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19
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Karki SJ, Reilly A, Zhou B, Mascarello M, Burke J, Doohan F, Douchkov D, Schweizer P, Feechan A. A small secreted protein from Zymoseptoria tritici interacts with a wheat E3 ubiquitin ligase to promote disease. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:733-746. [PMID: 33095257 PMCID: PMC7853600 DOI: 10.1093/jxb/eraa489] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 10/15/2020] [Indexed: 05/05/2023]
Abstract
Septoria tritici blotch (STB), caused by the ascomycete fungus Zymoseptoria tritici, is a major threat to wheat production worldwide. The Z. tritici genome encodes many small secreted proteins (ZtSSPs) that are likely to play a key role in the successful colonization of host tissues. However, few of these ZtSSPs have been functionally characterized for their role during infection. In this study, we identified and characterized a small, conserved cysteine-rich secreted effector from Z. tritici which has homologues in other plant pathogens in the Dothideomycetes. ZtSSP2 was expressed throughout Z. tritici infection in wheat, with the highest levels observed early during infection. A yeast two-hybrid assay revealed an interaction between ZtSSP2 and wheat E3 ubiquitin ligase (TaE3UBQ) in yeast, and this was further confirmed in planta using bimolecular fluorescence complementation and co-immunoprecipitation. Down-regulation of this wheat E3 ligase using virus-induced gene silencing increased the susceptibility of wheat to STB. Together, these results suggest that TaE3UBQ is likely to play a role in plant immunity to defend against Z. tritici.
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Affiliation(s)
- Sujit Jung Karki
- School of Agriculture & Food Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Aisling Reilly
- School of Agriculture & Food Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Binbin Zhou
- School of Biology and Environmental Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Maurizio Mascarello
- School of Agriculture & Food Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
- Ecology, Evolution and Biodiversity Conservation, Charles Deberiotstraat 8 32, 3000 Leuven, Belgium
| | - James Burke
- School of Agriculture & Food Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Fiona Doohan
- School of Biology and Environmental Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Dimitar Douchkov
- Institute of Plant Genetics and Crop Plant Research (IPK), Cytogenetics, Gatersleben, Germany
| | - Patrick Schweizer
- Institute of Plant Genetics and Crop Plant Research (IPK), Cytogenetics, Gatersleben, Germany
| | - Angela Feechan
- School of Agriculture & Food Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
- Correspondence:
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20
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Asynchronous development of Zymoseptoria tritici infection in wheat. Fungal Genet Biol 2020; 146:103504. [PMID: 33326850 PMCID: PMC7812371 DOI: 10.1016/j.fgb.2020.103504] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 12/04/2020] [Accepted: 12/04/2020] [Indexed: 12/22/2022]
Abstract
Zymoseptoria tritici passes 6 morphologically defined stages during infection. Surface-located spores and hyphae are found for up to 17/18 days. Entry through stomata occurs from 1 to 13 days post infection. Mesophyll apoplast colonisation continuously increases during infection. Up to 5 stages co-exist in infected leaves at a given time.
The fungus Zymoseptoria tritici causes Septoria tritici blotch of wheat. Pathogenicity begins with spore germination, followed by stomata invasion by hyphae, mesophyll colonization and fruiting body formation. It was previously found that entry into the plant via stomata occurs in a non-synchronized way over several days, while later developmental steps, such as early and late fruiting body formation, were reported to follow each other in time. This suggests synchronization of the pathogen population in planta prior to sporulation. Here, we image a fluorescent Z. tritici IPO323-derived strain during infection. We describe 6 morphologically distinct developmental stages, and determine their abundance in infected leaves, with time post inoculation. This demonstrates that 3-5 stages co-exist in infected tissues at any given time. Thus, later stages of pathogen development also occur asynchronously amongst the population of infecting cells. This merits consideration when interpreting transcriptomics or proteomics data gathered from infected plants.
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21
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Kilaru S, Schuster M, Murray R, Steinberg G. Optimal timing for Agrobacterium-mediated DNA transformation of Trichoderma reesei conidia revealed by live cell imaging. Fungal Genet Biol 2020; 142:103448. [PMID: 32866613 DOI: 10.1016/j.fgb.2020.103448] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/15/2020] [Accepted: 08/20/2020] [Indexed: 11/19/2022]
Abstract
Trichoderma reesei is the foremost fungal producer of enzymes for industrial processes. Here, we use fluorescent live cell imaging of germinating conidia to improve Agrobacterium tumefaciens-mediated transformation (ATMT) efficiency. We define the timing of (a) morphological changes and (b) nuclear reorganisation during initial conidia germination. This reveals that conidia swell for 7 h, during which nuclei undergo 2 non-synchronised mitotic divisions. Histones are recruited to the nucleus during the first 2 h, suggesting that conidia enter S-phase immediately after activation. This correlates with a significantly increased ATMT efficiency at 2 h after germination initiation. This finding promises to improve genetic manipulation efficiency in T. reesei.
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Affiliation(s)
- Sreedhar Kilaru
- School of Biosciences, University of Exeter, Exeter EX4 4QD, UK.
| | - Martin Schuster
- School of Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - Rachael Murray
- School of Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - Gero Steinberg
- School of Biosciences, University of Exeter, Exeter EX4 4QD, UK; University of Utrecht, Padualaan 8, Utrecht 3584 CH, the Netherlands.
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22
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Abstract
Most genomes within the species complex of Fusarium oxysporum are organized into two compartments: the core chromosomes (CCs) and accessory chromosomes (ACs). As opposed to CCs, which are conserved and vertically transmitted to carry out essential housekeeping functions, lineage- or strain-specific ACs are believed to be initially horizontally acquired through unclear mechanisms. These two genomic compartments are different in terms of gene density, the distribution of transposable elements, and epigenetic markers. Although common in eukaryotes, the functional importance of ACs is uniquely emphasized among fungal species, specifically in relationship to fungal pathogenicity and their adaptation to diverse hosts. With a focus on the cross-kingdom fungal pathogen F. oxysporum, this review provides a summary of the differences between CCs and ACs based on current knowledge of gene functions, genome structures, and epigenetic signatures, and explores the transcriptional crosstalk between the core and accessory genomes.
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23
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Mohammadi N, Mehrabi R, Mirzadi Gohari A, Roostaei M, Mohammadi Goltapeh E, Safaie N, Kema GHJ. MADS-Box Transcription Factor ZtRlm1 Is Responsible for Virulence and Development of the Fungal Wheat Pathogen Zymoseptoria tritici. Front Microbiol 2020; 11:1976. [PMID: 33013739 PMCID: PMC7461931 DOI: 10.3389/fmicb.2020.01976] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 07/27/2020] [Indexed: 11/13/2022] Open
Abstract
Zymoseptoria tritici is one of the most economically destructive wheat diseases all over the world and is a model fungal plant pathogen within the ascomycetes. In this study, the instrumental role of the ZtRlm1 gene encoding a MADS-box transcription factor (TF) in the infection process of Z. tritici was functionally characterized as these proteins play critical roles in the global gene regulation required for various developmental and physiological processes. Our infection assays showed that ZtRlm1 mutants were attenuated in disease development as a 30 and 90% reduction in chloro-necrotic lesions and pycnidia formation, respectively, were observed in plants inoculated with ZtRlm1 mutant strains demonstrating that ZtRlm1 is a crucial factor playing a significant role in the late stage of infection corresponding with pycnidial formation. Our expression analysis demonstrated that the transcript level of ZtRlm1 is induced at 2 and 20 days post-inoculation, coinciding with pycnidial sporulation. In addition, microscopic analyses showed that branch intensity and biomass production were significantly reduced, indicating that impaired pycnidia formation is a result of impaired differentiation and biomass production in the ZtRlm1 mutants. Furthermore, melanization, a phenomenon required for fruiting body formation, was significantly hampered in ZtRlm1 mutants as they were not melanized under all tested temperature and media conditions. Overall, our data showed that impaired disease development of the ZtRlm1 mutants is mainly due to the significant impact of ZtRlm1 in different cellular processes, including differentiation, branching, fungal biomass production, and melanization, in which identification of downstream genes are of interest to increase our understanding of this pathosystem.
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Affiliation(s)
- Naser Mohammadi
- Dryland Agricultural Research Institute, Agricultural Research, Education and Extension Organization (ARREO), Maragheh, Iran
| | - Rahim Mehrabi
- Department of Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan, Iran
| | - Amir Mirzadi Gohari
- Department of Plant Pathology, Faculty of Agricultural Sciences and Engineering, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
| | - Mozaffar Roostaei
- Dryland Agricultural Research Institute, Agricultural Research, Education and Extension Organization (ARREO), Maragheh, Iran
| | | | - Naser Safaie
- Department of Plant Pathology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran
| | - Gert H J Kema
- Wageningen University and Research, Wageningen Plant Research, Wageningen, Netherlands
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24
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Li Y, Han Y, Qu M, Chen J, Chen X, Geng X, Wang Z, Chen S. Apoplastic Cell Death-Inducing Proteins of Filamentous Plant Pathogens: Roles in Plant-Pathogen Interactions. Front Genet 2020; 11:661. [PMID: 32676100 PMCID: PMC7333776 DOI: 10.3389/fgene.2020.00661] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 06/01/2020] [Indexed: 11/13/2022] Open
Abstract
Filamentous pathogens, such as phytopathogenic oomycetes and fungi, secrete a remarkable diversity of apoplastic effector proteins to facilitate infection, many of which are able to induce cell death in plants. Over the past decades, over 177 apoplastic cell death-inducing proteins (CDIPs) have been identified in filamentous oomycetes and fungi. An emerging number of studies have demonstrated the role of many apoplastic CDIPs as essential virulence factors. At the same time, apoplastic CDIPs have been documented to be recognized by plant cells as pathogen-associated molecular patterns (PAMPs). The recent findings of extracellular recognition of apoplastic CDIPs by plant leucine-rich repeat-receptor-like proteins (LRR-RLPs) have greatly advanced our understanding of how plants detect them and mount a defense response. This review summarizes the latest advances in identifying apoplastic CDIPs of plant pathogenic oomycetes and fungi, and our current understanding of the dual roles of apoplastic CDIPs in plant-filamentous pathogen interactions.
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Affiliation(s)
- Ya Li
- Marine and Agricultural Biotechnology Laboratory, Institute of Oceanography, Minjiang University, Fuzhou, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yijuan Han
- Marine and Agricultural Biotechnology Laboratory, Institute of Oceanography, Minjiang University, Fuzhou, China
| | - Mengyu Qu
- Marine and Agricultural Biotechnology Laboratory, Institute of Oceanography, Minjiang University, Fuzhou, China
| | - Jia Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiaofeng Chen
- Marine and Agricultural Biotechnology Laboratory, Institute of Oceanography, Minjiang University, Fuzhou, China
| | - Xueqing Geng
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Zonghua Wang
- Marine and Agricultural Biotechnology Laboratory, Institute of Oceanography, Minjiang University, Fuzhou, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Songbiao Chen
- Marine and Agricultural Biotechnology Laboratory, Institute of Oceanography, Minjiang University, Fuzhou, China
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Wood AKM, Walker C, Lee WS, Urban M, Hammond-Kosack KE. Functional evaluation of a homologue of plant rapid alkalinisation factor (RALF) peptides in Fusarium graminearum. Fungal Biol 2020; 124:753-765. [PMID: 32883427 PMCID: PMC7487784 DOI: 10.1016/j.funbio.2020.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 04/01/2020] [Accepted: 05/12/2020] [Indexed: 02/08/2023]
Abstract
The cereal infecting fungus Fusarium graminearum is predicted to possess a single homologue of plant RALF (rapid alkalinisation factor) peptides. Fusarium mutant strains lacking FgRALF were generated and found to exhibit wildtype virulence on wheat and Arabidopsis floral tissue. Arabidopsis lines constitutively overexpressing FgRALF exhibited no obvious change in susceptibility to F. graminearum leaf infection. In contrast transient virus-mediated over-expression (VOX) of FgRALF in wheat prior to F. graminearum infection, slightly increased the rate of fungal colonisation of floral tissue. Ten putative Feronia (FER) receptors of RALF peptide were identified bioinformatically in hexaploid wheat (Triticum aestivum). Transient silencing of two wheat FER homoeologous genes prior to F. graminearum inoculation did not alter the subsequent interaction outcome. Collectively, our VOX results show that the fungal RALF peptide may be a minor contributor in F. graminearum virulence but results from fungal gene deletion experiments indicate potential functional redundancy within the F. graminearum genome. We demonstrate that virus-mediated over-expression is a useful tool to provide novel information about gene/protein function when results from gene deletion/disruption experimentation were uninformative.
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Affiliation(s)
- Ana K M Wood
- Department of Biointeractions and Crop Protection, Rothamsted Research, Harpenden, AL5 2JQ, UK
| | - Catherine Walker
- Department of Biointeractions and Crop Protection, Rothamsted Research, Harpenden, AL5 2JQ, UK
| | - Wing-Sham Lee
- Department of Biointeractions and Crop Protection, Rothamsted Research, Harpenden, AL5 2JQ, UK
| | - Martin Urban
- Department of Biointeractions and Crop Protection, Rothamsted Research, Harpenden, AL5 2JQ, UK
| | - Kim E Hammond-Kosack
- Department of Biointeractions and Crop Protection, Rothamsted Research, Harpenden, AL5 2JQ, UK.
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27
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Seybold H, Demetrowitsch TJ, Hassani MA, Szymczak S, Reim E, Haueisen J, Lübbers L, Rühlemann M, Franke A, Schwarz K, Stukenbrock EH. A fungal pathogen induces systemic susceptibility and systemic shifts in wheat metabolome and microbiome composition. Nat Commun 2020; 11:1910. [PMID: 32313046 PMCID: PMC7171108 DOI: 10.1038/s41467-020-15633-x] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 03/13/2020] [Indexed: 12/14/2022] Open
Abstract
Yield losses caused by fungal pathogens represent a major threat to global food production. One of the most devastating fungal wheat pathogens is Zymoseptoria tritici. Despite the importance of this fungus, the underlying mechanisms of plant–pathogen interactions are poorly understood. Here we present a conceptual framework based on coinfection assays, comparative metabolomics, and microbiome profiling to study the interaction of Z. tritici in susceptible and resistant wheat. We demonstrate that Z. tritici suppresses the production of immune-related metabolites in a susceptible cultivar. Remarkably, this fungus-induced immune suppression spreads within the leaf and even to other leaves, a phenomenon that we term “systemic induced susceptibility”. Using a comparative metabolomics approach, we identify defense-related biosynthetic pathways that are suppressed and induced in susceptible and resistant cultivars, respectively. We show that these fungus-induced changes correlate with changes in the wheat leaf microbiome. Our findings suggest that immune suppression by this hemibiotrophic pathogen impacts specialized plant metabolism, alters its associated microbial communities, and renders wheat vulnerable to further infections. The fungal plant pathogen Zymoseptoria tritici is a major threat to wheat yield. Here Seybold et al. show that Z. tritici can suppress immune responses not only in infected tissue but also on other leaves, a phenomenon termed “systemic induced susceptibility” that is correlated with systemic changes in metabolite accumulation.
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Affiliation(s)
- Heike Seybold
- Botanical Institute, Kiel University, Am Botanischen Garten 1-9, 24118, Kiel, Germany.,Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany.,Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem, 9190401, Israel
| | - Tobias J Demetrowitsch
- Institute of Human Nutrition and Food Science, Kiel University, Heinrich-Hecht-Platz 10, 24118, Kiel, Germany
| | - M Amine Hassani
- Botanical Institute, Kiel University, Am Botanischen Garten 1-9, 24118, Kiel, Germany.,Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany
| | - Silke Szymczak
- Institute of Medical Informatics and Statistics, Kiel University, University Hospital Schleswig Holstein Campus Kiel, Arnold-Heller-Str. 3, 24105, Kiel, Germany
| | - Ekaterina Reim
- Botanical Institute, Kiel University, Am Botanischen Garten 1-9, 24118, Kiel, Germany.,Institute of Human Nutrition and Food Science, Kiel University, Heinrich-Hecht-Platz 10, 24118, Kiel, Germany
| | - Janine Haueisen
- Botanical Institute, Kiel University, Am Botanischen Garten 1-9, 24118, Kiel, Germany.,Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany
| | - Luisa Lübbers
- Botanical Institute, Kiel University, Am Botanischen Garten 1-9, 24118, Kiel, Germany
| | - Malte Rühlemann
- Institute of Clinical Molecular Biology, Kiel University, Am Botanischen Garten 11, 24118, Kiel, Germany
| | - Andre Franke
- Institute of Clinical Molecular Biology, Kiel University, Am Botanischen Garten 11, 24118, Kiel, Germany
| | - Karin Schwarz
- Institute of Human Nutrition and Food Science, Kiel University, Heinrich-Hecht-Platz 10, 24118, Kiel, Germany
| | - Eva H Stukenbrock
- Botanical Institute, Kiel University, Am Botanischen Garten 1-9, 24118, Kiel, Germany. .,Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany.
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Nazar Pour F, Cobos R, Rubio Coque JJ, Serôdio J, Alves A, Félix C, Ferreira V, Esteves AC, Duarte AS. Toxicity of Recombinant Necrosis and Ethylene-Inducing Proteins (NLPs) from Neofusicoccum parvum. Toxins (Basel) 2020; 12:E235. [PMID: 32272814 PMCID: PMC7232490 DOI: 10.3390/toxins12040235] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 03/28/2020] [Accepted: 04/01/2020] [Indexed: 11/18/2022] Open
Abstract
Neofusicoccum parvum is a fungal pathogen associated with a wide range of plant hosts. Despite being widely studied, the molecular mechanism of infection of N. parvum is still far from being understood. Analysis of N. parvum genome lead to the identification of six putative genes encoding necrosis and ethylene-inducing proteins (NLPs). The sequence of NLPs genes (NprvNep 1-6) were analyzed and four of the six NLP genes were successfully cloned, expressed in E. coli and purified by affinity chromatography. Pure recombinant proteins were characterized according to their phytotoxic and cytotoxic effects to tomato leaves and to mammalian Vero cells, respectively. These assays revealed that all NprvNeps tested are cytotoxic to Vero cells and also induce cell death in tomato leaves. NprvNep2 was the most toxic to Vero cells, followed by NprvNep1 and 3. NprvNep4 induced weaker, but, nevertheless, still significant toxic effects to Vero cells. A similar trend of toxicity was observed in tomato leaves: the most toxic was NprvNep 2 and the least toxic NprvNep 4. This study describes for the first time an overview of the NLP gene family of N. parvum and provides additional insights into its pathogenicity mechanism.
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Affiliation(s)
- Forough Nazar Pour
- CESAM-Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; (F.N.P.); (J.S.); (A.A.); (C.F.); (V.F.)
| | - Rebeca Cobos
- Instituto de Investigación de la Viña y el Vino (IIVV), Escuela de Ingeniería Agraria, Universidad de León, Avda. Portugal, 41, 24009 León, Spain; (R.C.); (J.J.R.C.)
| | - Juan José Rubio Coque
- Instituto de Investigación de la Viña y el Vino (IIVV), Escuela de Ingeniería Agraria, Universidad de León, Avda. Portugal, 41, 24009 León, Spain; (R.C.); (J.J.R.C.)
| | - João Serôdio
- CESAM-Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; (F.N.P.); (J.S.); (A.A.); (C.F.); (V.F.)
| | - Artur Alves
- CESAM-Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; (F.N.P.); (J.S.); (A.A.); (C.F.); (V.F.)
| | - Carina Félix
- CESAM-Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; (F.N.P.); (J.S.); (A.A.); (C.F.); (V.F.)
| | - Vanessa Ferreira
- CESAM-Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; (F.N.P.); (J.S.); (A.A.); (C.F.); (V.F.)
| | - Ana Cristina Esteves
- Faculty of Dental Medicine, Center for Interdisciplinary Research in Health, Universidade Católica Portuguesa, Estrada da Circunvalação, 3504-505 Viseu, Spain;
| | - Ana Sofia Duarte
- Faculty of Dental Medicine, Center for Interdisciplinary Research in Health, Universidade Católica Portuguesa, Estrada da Circunvalação, 3504-505 Viseu, Spain;
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Kange AM, Xia A, Si J, Li B, Zhang X, Ai G, He F, Dou D. The Fungal-Specific Transcription Factor VpFSTF1 Is Required for Virulence in Valsa pyri. Front Microbiol 2020; 10:2945. [PMID: 31998257 PMCID: PMC6965324 DOI: 10.3389/fmicb.2019.02945] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 12/06/2019] [Indexed: 01/12/2023] Open
Abstract
Valsa pyri is the causal agent of pear canker disease, which leads to enormous losses of pear production in eastern Asian, especially China. In this study, we identified a fungal-specific transcription factor 1 (termed as VpFSTF1) from V. pyri, which is highly conserved in fungi. To characterize its functions, we generated mutant and complementation strains in V. pyri and found that ΔVpFSTF1 mutants lost the ability to form fruiting bodies along with the reduced virulence. The radial growth of ΔVpFSTF1 mutant was sensitive to increasing concentrations of hydrogen peroxide (H2O2) and salicylic acid (SA). Moreover, RNA-sequencing (RNA-Seq) analysis of wild-type (WT) and ΔVpFSTF1 mutant strains was performed, and the results revealed 1,993 upregulated, and 2006 downregulated differentially expressed genes (DEGs) in the mutant. The DEGs were corresponding to the genes that are involved in amino acid metabolism, starch, and sucrose metabolism, gluconeogenesis, citrate cycle, and carbon metabolism. Interestingly, pathogen host interaction (PHI) analysis showed that 69 downregulated genes were related to virulence, suggesting that they might function downstream of VpFSTF1. Nine DEGs were further validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and the results were consistent with RNA-seq analysis. Furthermore, promoter regions were predicted, and VpFSTF1 binding activity was assessed. We demonstrated that five promoters are directly or indirectly targeted by VpFSTF1, including catalase-related peroxidase (VPIG_01209) and P450 family genes. Taken together, these findings indicate that VpFSTF1 is crucial for the virulence of V. pyri via direct or indirect regulation of downstream genes expression and lay an important foundation for understanding the molecular mechanism of V. pyri infection.
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Affiliation(s)
- Alex Machio Kange
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Ai Xia
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Jierui Si
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Bingxin Li
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Xiong Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Gan Ai
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Feng He
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China.,School of Life Sciences, Anhui Normal University, Wuhu, China
| | - Daolong Dou
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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Tiley AMM, White HJ, Foster GD, Bailey AM. The ZtvelB Gene Is Required for Vegetative Growth and Sporulation in the Wheat Pathogen Zymoseptoria tritici. Front Microbiol 2019; 10:2210. [PMID: 31632366 PMCID: PMC6779691 DOI: 10.3389/fmicb.2019.02210] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 09/10/2019] [Indexed: 11/13/2022] Open
Abstract
The ascomycete fungus Zymoseptoria tritici is the causal agent of Septoria Tritici Blotch (STB), a major disease of wheat across Europe. Current understanding of the genetic components and the environmental cues which influence development and pathogenicity of this fungus is limited. The velvet B gene, velB, has conserved roles in development, secondary metabolism, and pathogenicity across fungi. The function of this gene is best characterised in the model ascomycete fungus Aspergillus nidulans, where it is involved in co-ordinating the light response with downstream processes. There is limited knowledge of the role of light in Z. tritici, and of the molecular mechanisms underpinning the light response. We show that Z. tritici is able to detect light, and that the vegetative morphology of this fungus is influenced by light conditions. We also identify and characterise the Z. tritici velB gene, ZtvelB, by gene disruption. The ΔztvelB deletion mutants were fixed in a filamentous growth pattern and are unable to form yeast-like vegetative cells. Their morphology was similar under light and dark conditions, showing an impairment in light-responsive growth. In addition, the ΔztvelB mutants produced abnormal pycnidia that were impaired in macropycnidiospore production but could still produce viable infectious micropycnidiospores. Our results show that ZtvelB is required for yeast-like growth and asexual sporulation in Z. tritici, and we provide evidence for a role of ZtvelB in integrating light perception and developmental regulation in this important plant pathogenic fungus.
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Affiliation(s)
- Anna M. M. Tiley
- Molecular Plant Pathology and Fungal Biology, School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Hannah J. White
- School of Biology and Environmental Science, O’Brien Centre for Science, University College Dublin, Dublin, Ireland
| | - Gary D. Foster
- Molecular Plant Pathology and Fungal Biology, School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Andy M. Bailey
- Molecular Plant Pathology and Fungal Biology, School of Biological Sciences, University of Bristol, Bristol, United Kingdom
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31
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Cloning, characterization, in vitro and in planta expression of a necrosis-inducing Phytophthora protein 1 gene npp1 from Phytophthora cinnamomi. Mol Biol Rep 2019; 46:6453-6462. [PMID: 31571106 DOI: 10.1007/s11033-019-05091-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 09/22/2019] [Indexed: 10/25/2022]
Abstract
The soil-borne oomycete Phytophthora cinnamomi is a highly destructive Phytophthora species associated with the decline of forest. This pathogen secretes a novel class of necrosis-inducing proteins known as Nep1-like proteins (NLPs). In this work, we report the sequencing and molecular characterization of one of these proteins, more specifically the necrosis-inducing Phytophthora protein 1 (NPP1). The ORF of the npp1 gene (EMBL database AM403130) has 768 bp encoding a putative peptide of 256 amino acids with a molecular weight of approximately 25 kD. In order to understand its function, in vitro gene expression was studied during growth in different carbon sources (glucose, cellulose, and sawdust), and at different times of infection, in vivo by RT-qPCR. The highest expression of the npp1 gene occurred in glucose medium followed by sawdust. In vivo infection of Castanea sativa roots with P. cinnamomi revealed a decrease in npp1 expression from 12 to 24 h; at 36 h its expression increased suggesting the existence of a complex mechanism of defense/attack interaction between the pathogen and the host. Expression of recombinant npp1 gene was achieved in Pichia pastoris and assessed by SDS-PAGE analysis of the protein secreted into the culture supernatant, revealing the presence of the NPP1 protein.
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32
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Lenarčič T, Pirc K, Hodnik V, Albert I, Borišek J, Magistrato A, Nürnberger T, Podobnik M, Anderluh G. Molecular basis for functional diversity among microbial Nep1-like proteins. PLoS Pathog 2019; 15:e1007951. [PMID: 31479498 PMCID: PMC6743777 DOI: 10.1371/journal.ppat.1007951] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 09/13/2019] [Accepted: 06/29/2019] [Indexed: 11/18/2022] Open
Abstract
Necrosis and ethylene-inducing peptide 1 (Nep1)-like proteins (NLPs) are secreted by several phytopathogenic microorganisms. They trigger necrosis in various eudicot plants upon binding to plant sphingolipid glycosylinositol phosphorylceramides (GIPC). Interestingly, HaNLP3 from the obligate biotroph oomycete Hyaloperonospora arabidopsidis does not induce necrosis. We determined the crystal structure of HaNLP3 and showed that it adopts the NLP fold. However, the conformations of the loops surrounding the GIPC headgroup-binding cavity differ from those of cytotoxic Pythium aphanidermatum NLPPya. Essential dynamics extracted from μs-long molecular dynamics (MD) simulations reveals a limited conformational plasticity of the GIPC-binding cavity in HaNLP3 relative to toxic NLPs. This likely precludes HaNLP3 binding to GIPCs, which is the underlying reason for the lack of toxicity. This study reveals that mutations at key protein regions cause a switch between non-toxic and toxic phenotypes within the same protein scaffold. Altogether, these data provide evidence that protein flexibility is a distinguishing trait of toxic NLPs and highlight structural determinants for a potential functional diversification of non-toxic NLPs utilized by biotrophic plant pathogens.
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Affiliation(s)
- Tea Lenarčič
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova, Ljubljana, Slovenia
| | - Katja Pirc
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova, Ljubljana, Slovenia
| | - Vesna Hodnik
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova, Ljubljana, Slovenia
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva, Ljubljana, Slovenia
| | - Isabell Albert
- Center of Plant Molecular Biology (ZMBP), Eberhard-Karls-University Tübingen, Auf der Morgenstelle, Tübingen, Germany
| | - Jure Borišek
- CNR-IOM-Democritos at International School for Advanced Studies (SISSA), Trieste, Italy
| | - Alessandra Magistrato
- CNR-IOM-Democritos at International School for Advanced Studies (SISSA), Trieste, Italy
| | - Thorsten Nürnberger
- Center of Plant Molecular Biology (ZMBP), Eberhard-Karls-University Tübingen, Auf der Morgenstelle, Tübingen, Germany
- Department of Biochemistry, University of Johannesburg, Auckland Park, South Africa
| | - Marjetka Podobnik
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova, Ljubljana, Slovenia
- * E-mail: (MP); (GA)
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova, Ljubljana, Slovenia
- * E-mail: (MP); (GA)
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Seidl MF, Van den Ackerveken G. Activity and Phylogenetics of the Broadly Occurring Family of Microbial Nep1-Like Proteins. ANNUAL REVIEW OF PHYTOPATHOLOGY 2019; 57:367-386. [PMID: 31283435 DOI: 10.1146/annurev-phyto-082718-100054] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Necrosis- and ethylene-inducing peptide 1 (Nep1)-like proteins (NLP) have an extremely broad taxonomic distribution; they occur in bacteria, fungi, and oomycetes. NLPs come in two forms, those that are cytotoxic to eudicot plants and those that are noncytotoxic. Cytotoxic NLPs bind to glycosyl inositol phosphoryl ceramide (GIPC) sphingolipids that are abundant in the outer leaflet of plant plasma membranes. Binding allows the NLP to become cytolytic in eudicots but not monocots. The function of noncytotoxic NLPs remains enigmatic, but the expansion of NLP genes in oomycete genomes suggests they are important. Several plant species have evolved the capacity to recognize NLPs as molecular patterns and trigger plant immunity, e.g., Arabidopsis thaliana detects nlp peptides via the receptor-like protein RLP23. In this review, we provide a historical perspective from discovery to understanding of molecular mechanisms and describe the latest developments in the NLP field to shed light on these fascinating microbial proteins.
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Affiliation(s)
- Michael F Seidl
- Laboratory of Phytopathology, Wageningen University & Research, 6708 PB Wageningen, The Netherlands
- Theoretical Biology and Bioinformatics, Department of Biology, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Guido Van den Ackerveken
- Plant-Microbe Interactions, Department of Biology, Utrecht University, 3584 CH Utrecht, The Netherlands;
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Kettles GJ, Hofinger BJ, Hu P, Bayon C, Rudd JJ, Balmer D, Courbot M, Hammond-Kosack KE, Scalliet G, Kanyuka K. sRNA Profiling Combined With Gene Function Analysis Reveals a Lack of Evidence for Cross-Kingdom RNAi in the Wheat - Zymoseptoria tritici Pathosystem. FRONTIERS IN PLANT SCIENCE 2019; 10:892. [PMID: 31333714 PMCID: PMC6620828 DOI: 10.3389/fpls.2019.00892] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 06/21/2019] [Indexed: 05/19/2023]
Abstract
Cross-kingdom small RNA (sRNA) silencing has recently emerged as a mechanism facilitating fungal colonization and disease development. Here we characterized RNAi pathways in Zymoseptoria tritici, a major fungal pathogen of wheat, and assessed their contribution to pathogenesis. Computational analysis of fungal sRNA and host mRNA sequencing datasets was used to define the global sRNA populations in Z. tritici and predict their mRNA targets in wheat. 389 in planta-induced sRNA loci were identified. sRNAs generated from some of these loci were predicted to target wheat mRNAs including those potentially involved in pathogen defense. However, molecular approaches failed to validate targeting of selected wheat mRNAs by fungal sRNAs. Mutant strains of Z. tritici carrying deletions of genes encoding key components of RNAi such as Dicer-like (DCL) and Argonaute (AGO) proteins were generated, and virulence bioassays suggested that these are dispensable for full infection of wheat. Nonetheless, our results did suggest the existence of non-canonical DCL-independent pathway(s) for sRNA biogenesis in Z. tritici. dsRNA targeting essential fungal genes applied in vitro or generated from an RNA virus vector in planta in a procedure known as HIGS (Host-Induced Gene Silencing) was ineffective in preventing Z. tritici growth or disease. We also demonstrated that Z. tritici is incapable of dsRNA uptake. Collectively, our data suggest that RNAi approaches for gene function analyses in this fungal species and potentially also as a control measure may not be as effective as has been demonstrated for some other plant pathogenic fungi.
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Affiliation(s)
- Graeme J. Kettles
- Biointeractions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom
| | - Bernhard J. Hofinger
- Biointeractions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom
| | - Pingsha Hu
- Syngenta Biotechnology, Inc., Research Triangle Park, NC, United States
| | - Carlos Bayon
- Biointeractions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom
| | - Jason J. Rudd
- Biointeractions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom
| | - Dirk Balmer
- Syngenta Crop Protection AG, Stein, Switzerland
| | | | | | | | - Kostya Kanyuka
- Biointeractions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom
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Levin E, Raphael G, Ma J, Ballester AR, Feygenberg O, Norelli J, Aly R, Gonzalez-Candelas L, Wisniewski M, Droby S. Identification and Functional Analysis of NLP-Encoding Genes from the Postharvest Pathogen Penicillium expansum. Microorganisms 2019; 7:microorganisms7060175. [PMID: 31208074 PMCID: PMC6616513 DOI: 10.3390/microorganisms7060175] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 06/03/2019] [Accepted: 06/13/2019] [Indexed: 12/25/2022] Open
Abstract
Penicillium expansum is a major postharvest pathogen that infects different fruits, mainly through injuries inflicted during harvest or subsequent handling after harvest. Several effectors were suggested to mediate pathogenicity of P. expansum in fruit tissue. Among these effectors Nep1-like proteins (NLPs), produced by various microorganisms with different lifestyles, are known for their ability to induce necrosis in dicot plants and were shown to be involved in virulence of several plant-related pathogens. This study was aimed at the identification and functional characterization of two NLP genes found in the genome of P. expansum. The genes were designated Penlp1 and Penlp2 and were found to code type1 and type3 NLP respectively. Necrosis-inducing activity of the two proteins was demonstrated by transient expression in Nicotiana benthamiana leaves. While Penlp1 expression was induced during apple infection and in liquid culture, the highest level of Penlp2 expression was found in ungerminated spores. Deletion of Penlp1, but not Penlp2, resulted in reduced virulence on apples manifested by reduced rate of lesion development (disease severity).
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Affiliation(s)
- Elena Levin
- Department of Postharvest Science, Agricultural Research Organization, the Volcani Center, Rishon LeZion 7505101, Israel.
| | - Ginat Raphael
- Department of Postharvest Science, Agricultural Research Organization, the Volcani Center, Rishon LeZion 7505101, Israel.
| | - Jing Ma
- Appalachian Fruit Research Station, Agricultural Research Service, United States Department of Agriculture, Wiltshire Road, Kearneysville, WV 25430, USA.
| | - Ana-Rosa Ballester
- Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Calle Catedrático Agustin Escardino 7, Paterna 46980, Valencia 46980, Spain.
| | - Oleg Feygenberg
- Department of Postharvest Science, Agricultural Research Organization, the Volcani Center, Rishon LeZion 7505101, Israel.
| | - John Norelli
- Appalachian Fruit Research Station, Agricultural Research Service, United States Department of Agriculture, Wiltshire Road, Kearneysville, WV 25430, USA.
| | - Radi Aly
- Department of Plant Pathology and Weed Research, ARO, the Volcani Center, Newe-Yaar Research Center, Ramat Yeshai 30095, Israel.
| | - Luis Gonzalez-Candelas
- Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Calle Catedrático Agustin Escardino 7, Paterna 46980, Valencia 46980, Spain.
| | - Michael Wisniewski
- Appalachian Fruit Research Station, Agricultural Research Service, United States Department of Agriculture, Wiltshire Road, Kearneysville, WV 25430, USA.
| | - Samir Droby
- Department of Postharvest Science, Agricultural Research Organization, the Volcani Center, Rishon LeZion 7505101, Israel.
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Dallery J, Adelin É, Le Goff G, Pigné S, Auger A, Ouazzani J, O'Connell RJ. H3K4 trimethylation by CclA regulates pathogenicity and the production of three families of terpenoid secondary metabolites in Colletotrichum higginsianum. MOLECULAR PLANT PATHOLOGY 2019; 20:831-842. [PMID: 30924614 PMCID: PMC6637877 DOI: 10.1111/mpp.12795] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The role of histone 3 lysine 4 (H3K4) methylation is poorly understood in plant pathogenic fungi. Here, we analysed the function of CclA, a subunit of the COMPASS complex mediating H3K4 methylation, in the brassica anthracnose pathogen Colletotrichum higginsianum. We show that CclA is required for full genome-wide H3K4 trimethylation. The deletion of cclA strongly reduced mycelial growth, asexual sporulation and spore germination but did not impair the morphogenesis of specialized infection structures (appressoria and biotrophic hyphae). Virulence of the ΔcclA mutant on plants was strongly attenuated, associated with a marked reduction in appressorial penetration ability on both plants and inert cellophane membranes. The secondary metabolite profile of the ΔcclA mutant was greatly enriched compared to that of the wild type, with three different families of terpenoid compounds being overproduced by the mutant, namely the colletochlorins, higginsianins and sclerosporide. These included five novel molecules that were produced exclusively by the ΔcclA mutant: colletorin D, colletorin D acid, higginsianin C, 13-epi-higginsianin C and sclerosporide. Taken together, our findings indicate that H3K4 trimethylation plays a critical role in regulating fungal growth, development, pathogenicity and secondary metabolism in C. higginsianum.
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Affiliation(s)
- Jean‐Félix Dallery
- UMR BIOGER, INRA, AgroParisTechUniversité Paris‐Saclay78850Thiverval‐GrignonFrance
- Centre National de la Recherche ScientifiqueInstitut de Chimie des Substances Naturelles ICSNAvenue de la Terrasse91198Gif‐sur‐Yvette, cedexFrance
| | - Émilie Adelin
- Centre National de la Recherche ScientifiqueInstitut de Chimie des Substances Naturelles ICSNAvenue de la Terrasse91198Gif‐sur‐Yvette, cedexFrance
| | - Géraldine Le Goff
- Centre National de la Recherche ScientifiqueInstitut de Chimie des Substances Naturelles ICSNAvenue de la Terrasse91198Gif‐sur‐Yvette, cedexFrance
| | - Sandrine Pigné
- UMR BIOGER, INRA, AgroParisTechUniversité Paris‐Saclay78850Thiverval‐GrignonFrance
| | - Annie Auger
- UMR BIOGER, INRA, AgroParisTechUniversité Paris‐Saclay78850Thiverval‐GrignonFrance
| | - Jamal Ouazzani
- Centre National de la Recherche ScientifiqueInstitut de Chimie des Substances Naturelles ICSNAvenue de la Terrasse91198Gif‐sur‐Yvette, cedexFrance
| | - Richard J. O'Connell
- UMR BIOGER, INRA, AgroParisTechUniversité Paris‐Saclay78850Thiverval‐GrignonFrance
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37
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Dilks T, Halsey K, De Vos RP, Hammond-Kosack KE, Brown NA. Non-canonical fungal G-protein coupled receptors promote Fusarium head blight on wheat. PLoS Pathog 2019; 15:e1007666. [PMID: 30934025 PMCID: PMC6459559 DOI: 10.1371/journal.ppat.1007666] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 04/11/2019] [Accepted: 02/28/2019] [Indexed: 12/26/2022] Open
Abstract
Fusarium Head Blight (FHB) is the number one floral disease of cereals and poses a serious health hazard by contaminating grain with the harmful mycotoxin deoxynivalenol (DON). Fungi adapt to fluctuations in their environment, coordinating development and metabolism accordingly. G-protein coupled receptors (GPCRs) communicate changes in the environment to intracellular G-proteins that direct the appropriate biological response, suggesting that fungal GPCR signalling may be key to virulence. Here we describe the expansion of non-classical GPCRs in the FHB causing pathogen, Fusarium graminearum, and show that class X receptors are highly expressed during wheat infection. We identify class X receptors that are required for FHB disease on wheat, and show that the absence of a GPCR can cause an enhanced host response that restricts the progression of infection. Specific receptor sub-domains are required for virulence. These non-classical receptors physically interact with intracellular G-proteins and are therefore bona fide GPCRs. Disrupting a class X receptor is shown to dysregulate the transcriptional coordination of virulence traits during infection. This amounts to enhanced wheat defensive responses, including chitinase and plant cell wall biosynthesis, resulting in apoplastic and vascular occlusions that impede infection. Our results show that GPCR signalling is important to FHB disease establishment. Fusarium Head Blight (FHB) is the number one floral disease of cereals and poses a serious health hazard by contaminating grain with harmful mycotoxins. Fusarium graminearum adapts to the host plant environment, coordinating fungal development, metabolism and virulence. Here we show that non-classical G-protein coupled receptors (GPCRs) contribute to FHB disease on wheat, promoting symptomless infection through their regulation of fungal membrane, mycotoxin and secreted protein biosynthesis. Disruption of GPCR host sensing activated an enhanced wheat defensive response to infection. This amounts to increased chitinase and plant cell wall biosynthesis, resulting in apoplastic and vascular occlusions that impede the progression of symptomless infection. These non-classical receptors were confirmed to be bona fide G-protein interactors, and specific receptors domains were required for virulence. Our results show that GPCR signalling is important to FHB disease establishment. The discovery of fungal GPCRs and specific extracellular domains that influence sterol membrane and mycotoxin biosynthesis, while contributing to virulence, opens new avenues for biotechnology to minimise diseases in crop species.
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Affiliation(s)
- Tess Dilks
- Biointeractions and Crop Protection, Rothamsted Research, Hertfordshire, United Kingdom
| | - Kirstie Halsey
- Computational and Analytical Sciences, Rothamsted Research, Hertfordshire, United Kingdom
| | - Rebecca P De Vos
- Computational and Analytical Sciences, Rothamsted Research, Hertfordshire, United Kingdom
| | - Kim E Hammond-Kosack
- Biointeractions and Crop Protection, Rothamsted Research, Hertfordshire, United Kingdom
| | - Neil Andrew Brown
- Biointeractions and Crop Protection, Rothamsted Research, Hertfordshire, United Kingdom.,Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath, United Kingdom
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38
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Wen Z, Raffaello T, Zeng Z, Pavicic M, Asiegbu FO. Chlorophyll fluorescence imaging for monitoring effects of Heterobasidion parviporum small secreted protein induced cell death and in planta defense gene expression. Fungal Genet Biol 2019; 126:37-49. [PMID: 30763724 DOI: 10.1016/j.fgb.2019.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 01/31/2019] [Accepted: 02/08/2019] [Indexed: 02/01/2023]
Abstract
Heterobasidion parviporum Niemelä & Korhonen is a necrotrophic fungal pathogen of Norway spruce (Picea abies). The H. parviporum genome encodes numerous necrotrophic small secreted proteins (SSP) which might be important for promoting and sustaining the disease development. However, their transcriptional dynamics and plant defense response during infection are largely unknown. In this study, we identified a necrotrophic SSP named HpSSP35.8 and its coding gene was highly expressed in the pre-symptomatic phase of the host (Norway spruce) infection. We explored the impact of HpSSP35.8 on non-host Nicotiana benthamiana using Agrobacterium-mediated transient expression system under visible spectrum RGB imaging and chlorophyll fluorescence imaging. The results showed that HpSSP35.8 triggered a form of SSP-associated programmed cell death, accompanied by a decrease in the plant photosynthetic activity. Defense-related genes including WRKY12, ethylene response factor (ERF1α) and a chitinase gene PR4 were up-regulated in both HpSSP35.8-N. benthamiana interaction and H. parviporum-Norway spruce pathosystem. This study also highlighted the potential to use the chlorophyll fluorescence imaging approach to monitor both the indirect effects of SSP and also for the selection of other potential effector-like protein candidates.
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Affiliation(s)
- Zilan Wen
- Faculty of Agriculture and Forestry, P. O. Box 27, Latokartanonkaari 7, 00014, University of Helsinki, Helsinki, Finland; Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Tommaso Raffaello
- Faculty of Agriculture and Forestry, P. O. Box 27, Latokartanonkaari 7, 00014, University of Helsinki, Helsinki, Finland
| | - Zhen Zeng
- Faculty of Agriculture and Forestry, P. O. Box 27, Latokartanonkaari 7, 00014, University of Helsinki, Helsinki, Finland; Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Mirko Pavicic
- Faculty of Agriculture and Forestry, P. O. Box 27, Latokartanonkaari 7, 00014, University of Helsinki, Helsinki, Finland; Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Fred O Asiegbu
- Faculty of Agriculture and Forestry, P. O. Box 27, Latokartanonkaari 7, 00014, University of Helsinki, Helsinki, Finland; Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland.
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39
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Hobbs CAD, Potts RWA, Bjerregaard Walsh M, Usher J, Griffiths AM. Using DNA Barcoding to Investigate Patterns of Species Utilisation in UK Shark Products Reveals Threatened Species on Sale. Sci Rep 2019; 9:1028. [PMID: 30705397 PMCID: PMC6355914 DOI: 10.1038/s41598-018-38270-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 12/18/2018] [Indexed: 12/14/2022] Open
Abstract
Many shark populations are in decline, primarily due to overexploitation. In response, conservation measures have been applied at differing scales, often severely restricting sales of declining species. Therefore, DNA barcoding was used to investigate sales of shark products in fishmongers and fish and chip takeaways in England. The majority of samples were identified as Spiny Dogfish (Squalus acanthias), which is critically endangered in the Northeast Atlantic and landings have been prohibited (although there is evidence of importation of this species). Significant differences in the species sold between retailer types were also identified, suggesting differing supply chains. The results underline issues surrounding the use of 'umbrella' sales terms where many species are labelled with the same designation. This denies consumer choice as purchasers cannot easily avoid declining species or those associated with high levels of toxicants. For the first time in Europe, minibarcodes are also used to identify species from dried shark fins. Despite a small sample size, analysis of UK wholesaler fins identified threatened sharks, including the endangered and CITES listed Scalloped Hammerhead (Sphyrna lewini). This highlights the global nature of the damaging trade in endangered shark species, in which Europe and the UK have a continuing role.
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Affiliation(s)
- Catherine A D Hobbs
- Department of Biosciences, Hatherly Laboratories, University of Exeter, Prince of Wales Road, Exeter, EX4 4PS, UK
| | - Robert W A Potts
- Department of Biosciences, Hatherly Laboratories, University of Exeter, Prince of Wales Road, Exeter, EX4 4PS, UK
| | | | - Jane Usher
- Department of Biosciences, Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
| | - Andrew M Griffiths
- Department of Biosciences, Hatherly Laboratories, University of Exeter, Prince of Wales Road, Exeter, EX4 4PS, UK.
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40
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Cobos R, Calvo-Peña C, Álvarez-Pérez JM, Ibáñez A, Diez-Galán A, González-García S, García-Angulo P, Acebes JL, Coque JJR. Necrotic and Cytolytic Activity on Grapevine Leaves Produced by Nep1-Like Proteins of Diplodia seriata. FRONTIERS IN PLANT SCIENCE 2019; 10:1282. [PMID: 31749815 PMCID: PMC6843023 DOI: 10.3389/fpls.2019.01282] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 09/13/2019] [Indexed: 05/22/2023]
Abstract
Many phytopathogenic fungi produce necrosis and ethylene inducing peptide 1 (Nep1-like proteins or NLP) that trigger leaf necrosis and the activation of defense mechanisms. These proteins have been widely studied in plant pathogens as Moniliophthora perniciosa or Botrytis cinerea between others, but little is known about their biological roles in grapevine trunk pathogens. Advances in the sequencing of genomes of several fungi involved in grapevine trunk diseases have revealed that these proteins are present in several copies in their genomes. The aim of this project was to analyze the presence of genes encoding NLP proteins in the Diplodia seriata genome and to characterize their putative role as virulence factors associated to grapevine trunk diseases. In this study, we characterized four NLPs from Diplodia seriata. All proteins showed highly similar amino acid sequences and contained the characteristic peptide motifs of NLPs. DserNEPs slightly reduced the viability of Vitis vinifera L. cell cultures. The cytolytic activity from DserNEP1 was stronger than that from DserNEP2, even at low concentrations. Purified DserNEPs also produced necrosis in leaves when they were inoculated into micropropagules of V. vinifera L. This is the first record of Nep1-like proteins from a fungus associated with grapevine trunk diseases and also from a member of the Botryosphaeriaceae family.
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Affiliation(s)
- Rebeca Cobos
- Instituto de Investigación de la Viña y el Vino, Universidad de León, León, Spain
- RGA-bioinvestigación S.L., León, Spain
- *Correspondence: Rebeca Cobos, ; Juan José Rubio Coque,
| | - Carla Calvo-Peña
- Instituto de Investigación de la Viña y el Vino, Universidad de León, León, Spain
| | | | - Ana Ibáñez
- Instituto de Investigación de la Viña y el Vino, Universidad de León, León, Spain
| | | | | | | | - Jose Luis Acebes
- Instituto de Investigación de la Viña y el Vino, Universidad de León, León, Spain
| | - Juan José R. Coque
- Instituto de Investigación de la Viña y el Vino, Universidad de León, León, Spain
- RGA-bioinvestigación S.L., León, Spain
- *Correspondence: Rebeca Cobos, ; Juan José Rubio Coque,
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41
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Haueisen J, Möller M, Eschenbrenner CJ, Grandaubert J, Seybold H, Adamiak H, Stukenbrock EH. Highly flexible infection programs in a specialized wheat pathogen. Ecol Evol 2019; 9:275-294. [PMID: 30680113 PMCID: PMC6342133 DOI: 10.1002/ece3.4724] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 10/04/2018] [Accepted: 10/05/2018] [Indexed: 12/21/2022] Open
Abstract
Many filamentous plant pathogens exhibit high levels of genomic variability, yet the impact of this variation on host-pathogen interactions is largely unknown. We have addressed host specialization in the wheat pathogen Zymoseptoria tritici. Our study builds on comparative analyses of infection and gene expression phenotypes of three isolates and reveals the extent to which genomic variation translates into phenotypic variation. The isolates exhibit genetic and genomic variation but are similarly virulent. By combining confocal microscopy, disease monitoring, staining of ROS, and comparative transcriptome analyses, we conducted a detailed comparison of the infection processes of these isolates in a susceptible wheat cultivar. We characterized four core infection stages: establishment, biotrophic growth, lifestyle transition, and necrotrophic growth and asexual reproduction that are shared by the three isolates. However, we demonstrate differentiated temporal and spatial infection development and significant differences in the expression profiles of the three isolates during the infection stages. More than 20% of the genes were differentially expressed and these genes were located significantly closer to transposable elements, suggesting an impact of epigenetic regulation. Further, differentially expressed genes were enriched in effector candidates suggesting that isolate-specific strategies for manipulating host defenses are present in Z. tritici. We demonstrate that individuals of a host-specialized pathogen have highly differentiated infection programs characterized by flexible infection development and functional redundancy. This illustrates how high genetic diversity in pathogen populations results in highly differentiated infection phenotypes, which fact needs to be acknowledged to understand host-pathogen interactions and pathogen evolution.
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Affiliation(s)
- Janine Haueisen
- Environmental Genomics GroupMax Planck Institute for Evolutionary BiologyPlönGermany
- Environmental Genomics GroupChristian‐Albrechts University KielKielGermany
| | - Mareike Möller
- Environmental Genomics GroupMax Planck Institute for Evolutionary BiologyPlönGermany
- Environmental Genomics GroupChristian‐Albrechts University KielKielGermany
| | - Christoph J. Eschenbrenner
- Environmental Genomics GroupMax Planck Institute for Evolutionary BiologyPlönGermany
- Environmental Genomics GroupChristian‐Albrechts University KielKielGermany
| | - Jonathan Grandaubert
- Environmental Genomics GroupMax Planck Institute for Evolutionary BiologyPlönGermany
- Fungal Biology and PathogenicityInstitute PasteurParisFrance
| | - Heike Seybold
- Environmental Genomics GroupMax Planck Institute for Evolutionary BiologyPlönGermany
- Environmental Genomics GroupChristian‐Albrechts University KielKielGermany
| | - Holger Adamiak
- Environmental Genomics GroupChristian‐Albrechts University KielKielGermany
| | - Eva H. Stukenbrock
- Environmental Genomics GroupMax Planck Institute for Evolutionary BiologyPlönGermany
- Environmental Genomics GroupChristian‐Albrechts University KielKielGermany
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42
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Derbyshire MC, Gohari AM, Mehrabi R, Kilaru S, Steinberg G, Ali S, Bailey A, Hammond-Kosack K, Kema GHJ, Rudd JJ. Phosphopantetheinyl transferase (Ppt)-mediated biosynthesis of lysine, but not siderophores or DHN melanin, is required for virulence of Zymoseptoria tritici on wheat. Sci Rep 2018; 8:17069. [PMID: 30459352 PMCID: PMC6244202 DOI: 10.1038/s41598-018-35223-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/30/2018] [Indexed: 12/19/2022] Open
Abstract
Zymoseptoria tritici is the causal agent of Septoria tritici blotch (STB) disease of wheat. Z. tritici is an apoplastic fungal pathogen, which does not penetrate plant cells at any stage of infection, and has a long initial period of symptomless leaf colonisation. During this phase it is unclear to what extent the fungus can access host plant nutrients or communicate with plant cells. Several important primary and secondary metabolite pathways in fungi are regulated by the post-translational activator phosphopantetheinyl transferase (Ppt) which provides an essential co-factor for lysine biosynthesis and the activities of non-ribosomal peptide synthases (NRPS) and polyketide synthases (PKS). To investigate the relative importance of lysine biosynthesis, NRPS-based siderophore production and PKS-based DHN melanin biosynthesis, we generated deletion mutants of ZtPpt. The ∆ZtPpt strains were auxotrophic for lysine and iron, non-melanised and non-pathogenic on wheat. Deletion of the three target genes likely affected by ZtPpt loss of function (Aar- lysine; Nrps1-siderophore and Pks1- melanin), highlighted that lysine auxotrophy was the main contributing factor for loss of virulence, with no reduction caused by loss of siderophore production or melanisation. This reveals Ppt, and the lysine biosynthesis pathway, as potential targets for fungicides effective against Z. tritici.
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Affiliation(s)
- Mark C Derbyshire
- BioIntercations and Crop Protection, Rothamsted Research, Harpenden, Hertfordshire, UK.,Centre for Crop and Disease Management, Curtin University, Perth, Australia
| | - Amir Mirzadi Gohari
- Department of Plant Pathology, Faculty of Agricultural Sciences and Engineering, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.,Wageningen University and Research, Wageningen Plant Research, PO Box 16, 6700AA, Wageningen, The Netherlands
| | - Rahim Mehrabi
- Department of Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan, 84156-83111, Iran
| | | | | | - Solaf Ali
- Technical College of Health, Sulaimani Polytechnic University, Qrga, Wrme Street, Mardin 327, Alley 76, Sulaimaniyah, Kurdistan Region of Iraq, Sulaimani Governorate, Iraq
| | - Andy Bailey
- School of Biological Sciences, Bristol University, 24 Tyndall Avenue, Bristol, UK
| | - Kim Hammond-Kosack
- BioIntercations and Crop Protection, Rothamsted Research, Harpenden, Hertfordshire, UK
| | - Gert H J Kema
- Wageningen University and Research, Wageningen Plant Research, PO Box 16, 6700AA, Wageningen, The Netherlands. .,Wageningen University and Research, Laboratory of Phytopathology, PO box 16, 6700AA, Wageningen, The Netherlands.
| | - Jason J Rudd
- BioIntercations and Crop Protection, Rothamsted Research, Harpenden, Hertfordshire, UK.
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43
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Tiley AMM, Foster GD, Bailey AM. Exploring the Genetic Regulation of Asexual Sporulation in Zymoseptoria tritici. Front Microbiol 2018; 9:1859. [PMID: 30154771 PMCID: PMC6102487 DOI: 10.3389/fmicb.2018.01859] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 07/24/2018] [Indexed: 01/03/2023] Open
Abstract
Zymoseptoria tritici is the causal agent of septoria tritici blotch, a devastating fungal disease of wheat which can cause up to 40% yield loss. One of the ways in which Z. tritici spreads in the field is via rain splash-dispersed asexual pycnidiospores, however there is currently limited understanding of the genetic mechanisms governing the development of these propagules. In order to explore whether the existing models for conidiation in ascomycete fungi apply to Z. tritici, homologs to the well-characterized Aspergillus nidulans genes abacus (abaA), bristle (brlA), fluffy B (flbB), fluffy C (flbC), and stunted (stuA) were identified and knocked-out by Agrobacterium-mediated transformation. Although deletion of the ZtAbaA, ZtBrlA1, and ZtFlbB genes had no apparent effect on Z. tritici asexual sporulation or on pathogenicity, deletion of ZtFlbC or ZtBrlA2 resulted in mutants with reduced pycnidiospore production compared to the parental IPO323 strain. Deletion of ZtStuA gave non-pigmented mutants with altered vegetative growth and eliminated asexual sporulation and pathogenicity. These findings suggest that the well-established A. nidulans model of asexual sporulation is only partially applicable to Z. tritici, and that this pathogen likely uses additional, as yet uncharacterized genes to control asexual sporulation.
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Affiliation(s)
- Anna M M Tiley
- Molecular Plant Pathology and Fungal Biology Group, School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Gary D Foster
- Molecular Plant Pathology and Fungal Biology Group, School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Andy M Bailey
- Molecular Plant Pathology and Fungal Biology Group, School of Biological Sciences, University of Bristol, Bristol, United Kingdom
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44
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Chen XR, Huang SX, Zhang Y, Sheng GL, Li YP, Zhu F. Identification and functional analysis of the NLP-encoding genes from the phytopathogenic oomycete Phytophthora capsici. Mol Genet Genomics 2018; 293:931-943. [PMID: 29572661 DOI: 10.1007/s00438-018-1432-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 03/21/2018] [Indexed: 10/17/2022]
Abstract
Phytophthora capsici is a hemibiotrophic, phytopathogenic oomycete that infects a wide range of crops, resulting in significant economic losses worldwide. By means of a diverse arsenal of secreted effector proteins, hemibiotrophic pathogens may manipulate plant cell death to establish a successful infection and colonization. In this study, we described the analysis of the gene family encoding necrosis- and ethylene-inducing peptide 1 (Nep1)-like proteins (NLPs) in P. capsici, and identified 39 real NLP genes and 26 NLP pseudogenes. Out of the 65 predicted NLP genes, 48 occur in groups with two or more genes, whereas the remainder appears to be singletons distributed randomly among the genome. Phylogenetic analysis of the 39 real NLPs delineated three groups. Key residues/motif important for the effector activities are degenerated in most NLPs, including the nlp24 peptide consisting of the conserved region I (11-aa immunogenic part) and conserved region II (the heptapeptide GHRHDWE motif) that is important for phytotoxic activity. Transcriptional profiling of eight selected NLP genes indicated that they were differentially expressed during the developmental and plant infection phases of P. capsici. Functional analysis of ten cloned NLPs demonstrated that Pc11951, Pc107869, Pc109174 and Pc118548 were capable of inducing cell death in the Solanaceae, including Nicotiana benthamiana and hot pepper. This study provides an overview of the P. capsici NLP gene family, laying a foundation for further elucidating the pathogenicity mechanism of this devastating pathogen.
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Affiliation(s)
- Xiao-Ren Chen
- College of Horticulture and Plant Protection, Yangzhou University, No. 48 Wenhui Eastern Road, Yangzhou, 225009, Jiangsu, China.
| | - Shen-Xin Huang
- College of Horticulture and Plant Protection, Yangzhou University, No. 48 Wenhui Eastern Road, Yangzhou, 225009, Jiangsu, China
| | - Ye Zhang
- College of Horticulture and Plant Protection, Yangzhou University, No. 48 Wenhui Eastern Road, Yangzhou, 225009, Jiangsu, China
| | - Gui-Lin Sheng
- College of Horticulture and Plant Protection, Yangzhou University, No. 48 Wenhui Eastern Road, Yangzhou, 225009, Jiangsu, China
| | - Yan-Peng Li
- College of Horticulture and Plant Protection, Yangzhou University, No. 48 Wenhui Eastern Road, Yangzhou, 225009, Jiangsu, China
| | - Feng Zhu
- College of Horticulture and Plant Protection, Yangzhou University, No. 48 Wenhui Eastern Road, Yangzhou, 225009, Jiangsu, China
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Kettles GJ, Bayon C, Sparks CA, Canning G, Kanyuka K, Rudd JJ. Characterization of an antimicrobial and phytotoxic ribonuclease secreted by the fungal wheat pathogen Zymoseptoria tritici. THE NEW PHYTOLOGIST 2018; 217:320-331. [PMID: 28895153 PMCID: PMC5724701 DOI: 10.1111/nph.14786] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 08/11/2017] [Indexed: 05/19/2023]
Abstract
The fungus Zymoseptoria tritici is the causal agent of Septoria Tritici Blotch (STB) disease of wheat leaves. Zymoseptoria tritici secretes many functionally uncharacterized effector proteins during infection. Here, we characterized a secreted ribonuclease (Zt6) with an unusual biphasic expression pattern. Transient expression systems were used to characterize Zt6, and mutants thereof, in both host and non-host plants. Cell-free protein expression systems monitored the impact of Zt6 protein on functional ribosomes, and in vitro assays of cells treated with recombinant Zt6 determined toxicity against bacteria, yeasts and filamentous fungi. We demonstrated that Zt6 is a functional ribonuclease and that phytotoxicity is dependent on both the presence of a 22-amino-acid N-terminal 'loop' region and its catalytic activity. Zt6 selectively cleaves both plant and animal rRNA species, and is toxic to wheat, tobacco, bacterial and yeast cells, but not to Z. tritici itself. Zt6 is the first Z. tritici effector demonstrated to have a likely dual functionality. The expression pattern of Zt6 and potent toxicity towards microorganisms suggest that, although it may contribute to the execution of wheat cell death, it is also likely to have an important secondary function in antimicrobial competition and niche protection.
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Affiliation(s)
- Graeme J. Kettles
- Biointeractions & Crop ProtectionRothamsted ResearchHarpendenAL5 2JQUK
| | - Carlos Bayon
- Biointeractions & Crop ProtectionRothamsted ResearchHarpendenAL5 2JQUK
| | | | - Gail Canning
- Biointeractions & Crop ProtectionRothamsted ResearchHarpendenAL5 2JQUK
| | - Kostya Kanyuka
- Biointeractions & Crop ProtectionRothamsted ResearchHarpendenAL5 2JQUK
| | - Jason J. Rudd
- Biointeractions & Crop ProtectionRothamsted ResearchHarpendenAL5 2JQUK
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Mohammadi N, Mehrabi R, Mirzadi Gohari A, Mohammadi Goltapeh E, Safaie N, Kema GHJ. The ZtVf1 transcription factor regulates development and virulence in the foliar wheat pathogen Zymoseptoria tritici. Fungal Genet Biol 2017; 109:26-35. [PMID: 29031630 DOI: 10.1016/j.fgb.2017.10.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 10/03/2017] [Accepted: 10/11/2017] [Indexed: 10/18/2022]
Abstract
The dimorphic fungal pathogen, Zymoseptoria tritici undergoes discrete developmental changes to complete its life cycle on wheat. Molecular mechanisms underlying morphogenesis during infection process of Z. tritici are poorly understood. In this study, we have investigated the role of ZtVf1 gene encoding a transcription factor belonging to C2-H2 subfamily. In planta assays revealed that ZtVf1 is required for virulence. Reduced necrotic lesions and low pycnidia density within the lesions resulted in significantly reduced virulence of ZtVf1 mutants. Cytological analysis showed that the impaired virulence of ZtVf1 mutants attributed to reduced penetration and colonization along with hampered pycnidia differentiation. In vitro phenotyping showed that ZtVf1 deletion affects hyphal branching and biomass production suggesting that the reduced tissue colonization by the ZtVf1 mutant might be due to lower hyphal branching and less fungal biomass production. In addition, the majority of infected substomatal cavities by the ZtVf1 mutant filled with compacted mycelia mat that did not differentiate to mature pycnidia indicating that the impaired melanization negatively affected pycnidia formation and maturation. The ZtVf1 might target multiple genes belonging to different cellular processes whose identification is of eminent interest to increase our understanding of this pathosystem. Overall, the data provided in this study indicates that attenuated pathogenicity of ZtVf1 mutant is due to involvement of this gene in the regulation of both early and late stages of infection.
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Affiliation(s)
- Naser Mohammadi
- Department of Plant Pathology, Faculty of Agriculture, Tarbiat Modares University, P.O. Box 14115-111, Tehran, Iran; Dryland Agricultural Research Institute, Agricultural Research, Education & Extension Organization (ARREO), Maragheh, Iran
| | - Rahim Mehrabi
- Seed & Plant Improvement Institute, Agricultural Research, Education & Extension Organization (ARREO), P.O. Box 31585-4119, Karaj, Iran; Department of Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan, Iran.
| | - Amir Mirzadi Gohari
- Department of Plant Pathology, Faculty of Agricultural Sciences and Engineering, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
| | - Ebrahim Mohammadi Goltapeh
- Department of Plant Pathology, Faculty of Agriculture, Tarbiat Modares University, P.O. Box 14115-111, Tehran, Iran
| | - Naser Safaie
- Department of Plant Pathology, Faculty of Agriculture, Tarbiat Modares University, P.O. Box 14115-111, Tehran, Iran
| | - Gert H J Kema
- Laboratory of Phytopathology, Wageningen University and Research, 6700AA Wageningen, The Netherlands; Wageningen University and Research, Wageningen Plant Research, P.O. Box 16, 6700AA Wageningen, The Netherlands
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King R, Urban M, Lauder RP, Hawkins N, Evans M, Plummer A, Halsey K, Lovegrove A, Hammond-Kosack K, Rudd JJ. A conserved fungal glycosyltransferase facilitates pathogenesis of plants by enabling hyphal growth on solid surfaces. PLoS Pathog 2017; 13:e1006672. [PMID: 29020037 PMCID: PMC5653360 DOI: 10.1371/journal.ppat.1006672] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 10/23/2017] [Accepted: 09/27/2017] [Indexed: 11/18/2022] Open
Abstract
Pathogenic fungi must extend filamentous hyphae across solid surfaces to cause diseases of plants. However, the full inventory of genes which support this is incomplete and many may be currently concealed due to their essentiality for the hyphal growth form. During a random T-DNA mutagenesis screen performed on the pleomorphic wheat (Triticum aestivum) pathogen Zymoseptoria tritici, we acquired a mutant unable to extend hyphae specifically when on solid surfaces. In contrast "yeast-like" growth, and all other growth forms, were unaffected. The inability to extend surface hyphae resulted in a complete loss of virulence on plants. The affected gene encoded a predicted type 2 glycosyltransferase (ZtGT2). Analysis of >800 genomes from taxonomically diverse fungi highlighted a generally widespread, but discontinuous, distribution of ZtGT2 orthologues, and a complete absence of any similar proteins in non-filamentous ascomycete yeasts. Deletion mutants of the ZtGT2 orthologue in the taxonomically un-related fungus Fusarium graminearum were also severely impaired in hyphal growth and non-pathogenic on wheat ears. ZtGT2 expression increased during filamentous growth and electron microscopy on deletion mutants (ΔZtGT2) suggested the protein functions to maintain the outermost surface of the fungal cell wall. Despite this, adhesion to leaf surfaces was unaffected in ΔZtGT2 mutants and global RNAseq-based gene expression profiling highlighted that surface-sensing and protein secretion was also largely unaffected. However, ΔZtGT2 mutants constitutively overexpressed several transmembrane and secreted proteins, including an important LysM-domain chitin-binding virulence effector, Zt3LysM. ZtGT2 likely functions in the synthesis of a currently unknown, potentially minor but widespread, extracellular or outer cell wall polysaccharide which plays a key role in facilitating many interactions between plants and fungi by enabling hyphal growth on solid matrices.
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Affiliation(s)
- Robert King
- Department of Computational and Analytical Sciences, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Martin Urban
- Wheat Pathogenomics Team, Department of BioInteractions and Crop Protection, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Rebecca P. Lauder
- Rothamsted Centre for Bioimaging, Department of Plant Sciences, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Nichola Hawkins
- Fungicide resistance group, Department of BioInteractions and Crop Protection, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Matthew Evans
- Cereal cell walls group, Department of Plant Sciences, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Amy Plummer
- Cereal cell walls group, Department of Plant Sciences, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Kirstie Halsey
- Rothamsted Centre for Bioimaging, Department of Plant Sciences, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Alison Lovegrove
- Cereal cell walls group, Department of Plant Sciences, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Kim Hammond-Kosack
- Wheat Pathogenomics Team, Department of BioInteractions and Crop Protection, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Jason J. Rudd
- Wheat Pathogenomics Team, Department of BioInteractions and Crop Protection, Rothamsted Research, Harpenden, Herts, United Kingdom
- * E-mail:
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The Nep1-like protein family of Magnaporthe oryzae is dispensable for the infection of rice plants. Sci Rep 2017; 7:4372. [PMID: 28663588 PMCID: PMC5491491 DOI: 10.1038/s41598-017-04430-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 05/15/2017] [Indexed: 01/02/2023] Open
Abstract
The necrosis- and ethylene-inducing protein 1 (Nep1)-like proteins (NLPs) are a class of microbe-associated molecular patterns widely distributed across diverse groups of plant-associated microorganisms. In spite of the cytotoxic activity in dicot plants, the role of most NLPs in the virulence of plant pathogens is still largely unknown. We showed that the MoNLP family of rice blast fungus varied very little in amino acid sequence, transient expression of three MoNLPs induced cell death and the production of reactive oxygen species in Nicotiana benthamiana, and the expression of MoNLPs was induced during infection of susceptible rice plants. To further investigate the biological role of the MoNLP family, a marker-free gene replacement vector was developed and used to knock out the whole family in Magnaporthe oryzae. Results showed no significant difference in disease levels caused by wild type and the quadruple ΔMoNLP mutant strains. Likewise, the sporulation and radial growth of the two strains were similar under various unfavorable cultural conditions including malnutrition and abiotic stresses. These observations demonstrated that the MoNLP family is dispensable for the fungal tolerance to the tested adverse cultural conditions, and more importantly, for the virulence of blast fungus on susceptible rice plants.
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