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Vasselli JG, Kainer E, Shaw BD. Using fimbrin to quantify the endocytic subapical collar during polarized growth in three filamentous fungi. Mycologia 2023:1-14. [PMID: 37196171 DOI: 10.1080/00275514.2023.2202689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 04/09/2023] [Indexed: 05/19/2023]
Abstract
Filamentous fungi produce specialized cells called hyphae. These cells grow by polarized extension at their apex, which is maintained by the balance of endocytosis and exocytosis at the apex. Although endocytosis has been well characterized in other organisms, the details of endocytosis and its role in maintaining polarity during hyphal growth in filamentous fungi is comparatively sparsely studied. In recent years, a concentrated region of protein activity that trails the growing apex of hyphal cells has been discovered. This region, dubbed the "endocytic collar" (EC), is a dynamic 3-dimensional region of concentrated endocytic activity, the disruption of which results in the loss of hyphal polarity. Here, fluorescent protein-tagged fimbrin was used as a marker to map the collar during growth of hyphae in three fungi: Aspergillus nidulans, Colletotrichum graminicola, and Neurospora crassa. Advanced microscopy techniques and novel quantification strategies were then utilized to quantify the spatiotemporal localization and recovery rates of fimbrin in the EC during hyphal growth. Correlating these variables with hyphal growth rate revealed that the strongest observed relationship with hyphal growth is the distance by which the EC trails the apex, and that measured endocytic rate does not correlate strongly with hyphal growth rate. This supports the hypothesis that endocytic influence on hyphal growth rate is better explained by spatiotemporal regulation of the EC than by the raw rate of endocytosis.
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Affiliation(s)
- Joseph G Vasselli
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843
| | - Ellen Kainer
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843
| | - Brian D Shaw
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843
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2
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Kariyawasam GK, Richards JK, Wyatt NA, Running KLD, Xu SS, Liu Z, Borowicz P, Faris JD, Friesen TL. The Parastagonospora nodorum necrotrophic effector SnTox5 targets the wheat gene Snn5 and facilitates entry into the leaf mesophyll. THE NEW PHYTOLOGIST 2022; 233:409-426. [PMID: 34231227 PMCID: PMC9291777 DOI: 10.1111/nph.17602] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/27/2021] [Indexed: 05/11/2023]
Abstract
Parastagonospora nodorum is an economically important necrotrophic fungal pathogen of wheat. Parastagonospora nodorum secretes necrotrophic effectors that target wheat susceptibility genes to induce programmed cell death (PCD). In this study, we cloned and functionally validated SnTox5 and characterized its role in pathogenesis. We used whole genome sequencing, genome-wide association study (GWAS) mapping, CRISPR-Cas9-based gene disruption, gain-of-function transformation, quantitative trait locus (QTL) analysis, haplotype and isoform analysis, protein modeling, quantitative PCR, and laser confocal microscopy to validate SnTox5 and functionally characterize SnTox5. SnTox5 is a mature 16.26 kDa protein with high structural similarity to SnTox3. Wild-type and mutant P. nodorum strains and wheat genotypes of SnTox5 and Snn5, respectively, were used to show that SnTox5 not only targets Snn5 to induce PCD but also facilitates the colonization of the mesophyll layer even in the absence of Snn5. Here we show that SnTox5 facilitates the efficient colonization of the mesophyll tissue and elicits PCD specific to host lines carrying Snn5. The homology to SnTox3 and the ability of SnTox5 to facilitate the colonizing of the mesophyll also suggest a role in the suppression of host defense before PCD induction.
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Affiliation(s)
| | - Jonathan K. Richards
- Department of Plant Pathology and Crop PhysiologyLouisiana State University – Agricultural CenterBaton RougeLA70803USA
| | - Nathan A. Wyatt
- Cereal Crops Research UnitUnited States Department of Agriculture‐Agricultural Research ServiceEdward T. Schafer Agricultural Research CenterFargoND58102USA
| | | | - Steven S. Xu
- Cereal Crops Research UnitUnited States Department of Agriculture‐Agricultural Research ServiceEdward T. Schafer Agricultural Research CenterFargoND58102USA
| | - Zhaohui Liu
- Department of Plant PathologyNorth Dakota State UniversityFargoND58102USA
| | - Pawel Borowicz
- Department of Animal SciencesNorth Dakota State UniversityFargoND58102USA
| | - Justin D. Faris
- Cereal Crops Research UnitUnited States Department of Agriculture‐Agricultural Research ServiceEdward T. Schafer Agricultural Research CenterFargoND58102USA
- Department of Plant ScienceNorth Dakota State UniversityFargoND58102USA
| | - Timothy L. Friesen
- Department of Plant PathologyNorth Dakota State UniversityFargoND58102USA
- Cereal Crops Research UnitUnited States Department of Agriculture‐Agricultural Research ServiceEdward T. Schafer Agricultural Research CenterFargoND58102USA
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3
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Richards JK, Kariyawasam GK, Seneviratne S, Wyatt NA, Xu SS, Liu Z, Faris JD, Friesen TL. A triple threat: the Parastagonospora nodorum SnTox267 effector exploits three distinct host genetic factors to cause disease in wheat. THE NEW PHYTOLOGIST 2022; 233:427-442. [PMID: 34227112 PMCID: PMC9292537 DOI: 10.1111/nph.17601] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/27/2021] [Indexed: 05/21/2023]
Abstract
Parastagonospora nodorum is a fungal pathogen of wheat. As a necrotrophic specialist, it deploys effector proteins that target dominant host susceptibility genes to elicit programmed cell death (PCD). Here we identify and functionally validate the effector targeting the host susceptibility genes Snn2, Snn6 and Snn7. We utilized whole-genome sequencing, association mapping, gene-disrupted mutants, gain-of-function transformants, virulence assays, bioinformatics and quantitative PCR to characterize these interactions. A single proteinaceous effector, SnTox267, targeted Snn2, Snn6 and Snn7 to trigger PCD. Snn2 and Snn6 functioned cooperatively to trigger PCD in a light-dependent pathway, whereas Snn7-mediated PCD functioned in a light-independent pathway. Isolates harboring 20 SnTox267 protein isoforms quantitatively varied in virulence. The diversity and distribution of isoforms varied between populations, indicating adaptation to local selection pressures. SnTox267 deletion resulted in the upregulation of effector genes SnToxA, SnTox1 and SnTox3. We validated a novel effector operating in an inverse-gene-for-gene manner to target three genetically distinct host susceptibility genes and elicit PCD. The discovery of the complementary gene action of Snn2 and Snn6 indicates their potential function in a guard or decoy model. Additionally, differences in light dependency in the elicited pathways and upregulation of unlinked effectors sheds new light onto a complex fungal necrotroph-host interaction.
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Affiliation(s)
- Jonathan K. Richards
- Department of Plant Pathology and Crop PhysiologyLouisiana State University Agricultural CenterBaton RougeLA70803USA
| | | | | | - Nathan A. Wyatt
- Cereal Crops Research UnitEdward T. Schaffer Agricultural Research CenterUSDA‐ARSFargoND58102USA
| | - Steven S. Xu
- Department of Plant SciencesNorth Dakota State UniversityFargoND58102USA
- Cereal Crops Research UnitEdward T. Schaffer Agricultural Research CenterUSDA‐ARSFargoND58102USA
| | - Zhaohui Liu
- Department of Plant PathologyNorth Dakota State UniversityFargoND58102USA
| | - Justin D. Faris
- Department of Plant SciencesNorth Dakota State UniversityFargoND58102USA
- Cereal Crops Research UnitEdward T. Schaffer Agricultural Research CenterUSDA‐ARSFargoND58102USA
| | - Timothy L. Friesen
- Department of Plant PathologyNorth Dakota State UniversityFargoND58102USA
- Cereal Crops Research UnitEdward T. Schaffer Agricultural Research CenterUSDA‐ARSFargoND58102USA
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4
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Kemppainen M, Pardo A. Nucleus-directed fluorescent reporter system for promoter studies in the ectomycorrhizal fungus Laccaria bicolor. J Microbiol Methods 2021; 190:106341. [PMID: 34610385 DOI: 10.1016/j.mimet.2021.106341] [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: 08/09/2021] [Revised: 09/30/2021] [Accepted: 09/30/2021] [Indexed: 11/19/2022]
Abstract
Currently ectomycorrhizal research suffers from a lack of molecular tools specifically adapted to study gene expression in fungal symbionts. Considering that, we designed pReNuK, a cloning vector for transcriptional promoter studies in the ectomycorrhizal basidiomycete Laccaria bicolor. The pReNuK vector offers the use of a nuclear localizing and chromatin incorporating histone H2B-mCherry fluorescent reporter protein and it is specifically optimized for efficient transgene expression in Laccaria. Moreover, pReNuK is designed to work in concert with Agrobacterium-mediated transformation under hygromycin B resistance selection. The functionality of the pReNuK reporter system was tested with the constitutive Laccaria glyceraldehyde 3-phosphate dehydrogenase gene promoter and further validated with the nitrogen source regulated nitrate reductase gene promoter. The expression of the nucleus-directed H2B-mCherry reporter is highly stable in time. Moreover, the transformation of Laccaria with pReNuK and the expression of the reporter do not have negative effects on the growth of the fungus. The pReNuK offers a novel tool for studying in vivo gene expression regulation in Laccaria, the leading fungal model for ectomycorrhizal research.
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Affiliation(s)
- Minna Kemppainen
- Laboratory of Molecular Mycology, Institute of Basic and Applied Microbiology, Department of Science and Technology, National University of Quilmes and CONICET, Bernal, Province of Buenos Aires, Argentina.
| | - Alejandro Pardo
- Laboratory of Molecular Mycology, Institute of Basic and Applied Microbiology, Department of Science and Technology, National University of Quilmes and CONICET, Bernal, Province of Buenos Aires, Argentina
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5
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Sadat MA, Han JH, Kim S, Lee YH, Kim KS, Choi J. The Membrane-Bound Protein, MoAfo1, Is Involved in Sensing Diverse Signals from Different Surfaces in the Rice Blast Fungus. THE PLANT PATHOLOGY JOURNAL 2021; 37:87-98. [PMID: 33866752 PMCID: PMC8053852 DOI: 10.5423/ppj.oa.08.2020.0154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 12/31/2020] [Accepted: 01/20/2021] [Indexed: 06/12/2023]
Abstract
To establish an infection, fungal pathogens must recognize diverse signals from host surfaces. The rice blast fungus, Magnaporthe oryzae, is one of the best models studying host-pathogen interactions. This fungus recognizes physical or chemical signals from the host surfaces and initiates the development of an infection structure called appressorium. Here, we found that protein MoAfo1(appressorium formation, MGG_10422) was involved in sensing signal molecules such as cutin monomers and long chain primary alcohols required for appressorium formation. The knockout mutant (ΔMoafo1) formed a few abnormal appressoria on the onion and rice sheath surfaces. However, it produced normal appressoria on the surface of rice leaves. MoAfo1 localized to the membranes of the cytoplasm and vacuole-like organelles in conidia and appressoria. Additionally, the ΔMoafo1 mutant showed defects in appressorium morphology, appressorium penetration, invasive growth, and pathogenicity. These multiple defects might be partially due to failure to respond properly to oxidative stress. These findings broaden our understanding of the fungal mechanisms at play in the recognition of the host surface during rice blast infection.
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Affiliation(s)
- Md Abu Sadat
- Division of Life Sciences, College of Life Sciences and Bioengineering, Incheon National University, Incheon 22012,
Korea
| | - Joon-Hee Han
- Division of Bioresource Sciences, Interdisciplinary Program in Smart Agriculture, College of Agriculture and Life Sciences, Kangwon National University, Chuncheon 24341,
Korea
| | - Seongbeom Kim
- Department of Agricultural Biotechnology, Center for Fungal Genetic Resources, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
| | - Yong-Hwan Lee
- Department of Agricultural Biotechnology, Center for Fungal Genetic Resources, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
| | - Kyoung Su Kim
- Division of Bioresource Sciences, Interdisciplinary Program in Smart Agriculture, College of Agriculture and Life Sciences, Kangwon National University, Chuncheon 24341,
Korea
| | - Jaehyuk Choi
- Division of Life Sciences, College of Life Sciences and Bioengineering, Incheon National University, Incheon 22012,
Korea
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6
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Two nuclear effectors of the rice blast fungus modulate host immunity via transcriptional reprogramming. Nat Commun 2020; 11:5845. [PMID: 33203871 PMCID: PMC7672089 DOI: 10.1038/s41467-020-19624-w] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 10/20/2020] [Indexed: 02/04/2023] Open
Abstract
Pathogens utilize multiple types of effectors to modulate plant immunity. Although many apoplastic and cytoplasmic effectors have been reported, nuclear effectors have not been well characterized in fungal pathogens. Here, we characterize two nuclear effectors of the rice blast pathogen Magnaporthe oryzae. Both nuclear effectors are secreted via the biotrophic interfacial complex, translocated into the nuclei of initially penetrated and surrounding cells, and reprogram the expression of immunity-associated genes by binding on effector binding elements in rice. Their expression in transgenic rice causes ambivalent immunity: increased susceptibility to M. oryzae and Xanthomonas oryzae pv. oryzae, hemibiotrophic pathogens, but enhanced resistance to Cochliobolus miyabeanus, a necrotrophic pathogen. Our findings help remedy a significant knowledge deficiency in the mechanism of M. oryzae–rice interactions and underscore how effector-mediated manipulation of plant immunity by one pathogen may also affect the disease severity by other pathogens. Plant pathogens secrete various effectors to manipulate host immunity. Here, Kim et al. describe two Magnaporthe oryzae effectors that translocate into the nuclei of infected rice cells and reprogram expression of immunity-associated genes, increasing susceptibility to hemibiotrophic pathogens.
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7
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Agrobacterium tumefaciens-Mediated Genetic Transformation of the Ect-endomycorrhizal Fungus Terfezia boudieri. Genes (Basel) 2020; 11:genes11111293. [PMID: 33143066 PMCID: PMC7693413 DOI: 10.3390/genes11111293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/22/2020] [Accepted: 10/29/2020] [Indexed: 01/05/2023] Open
Abstract
Mycorrhizal desert truffles such as Terfezia boudieri, Tirmania nivea, and Terfezia claveryi, form mycorrhizal associations with plants of the Cistaceae family. These valued truffles are still collected from the wild and not cultivated under intensive farming due to the lack of basic knowledge about their biology at all levels. Recently, several genomes of desert truffles have been decoded, enabling researchers to attempt genetic manipulations to enable cultivation. To execute such manipulations, the development of molecular tools for genes transformation into truffles is needed. We developed an Agrobacterium tumefaciens-mediated genetic transformation system in T. boudieri. This system was optimized for the developmental stage of the mycelia explants, bacterial optical density, infection and co-cultivation durations, and concentrations of the selection antibiotics. The pFPL-Rh plasmid harboring hph gene conferring hygromycin resistance as a selection marker and the red fluorescent protein gene were used as visual reporters. The optimal conditions were incubation with 200 μM of acetosyringone, attaining a bacterial optical density of 0.3 OD600; transfer time of 45 min; and co-cultivation for 3 days. This is the first report on a transformation system for T. boudieri, and the proposed protocol can be adapted for the transformation of other important desert truffles as well as ectomycorrhizal species.
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8
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Kemppainen M, Chowdhury J, Lundberg-Felten J, Pardo A. Fluorescent protein expression in the ectomycorrhizal fungus Laccaria bicolor: a plasmid toolkit for easy use of fluorescent markers in basidiomycetes. Curr Genet 2020; 66:791-811. [PMID: 32170354 DOI: 10.1007/s00294-020-01060-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/22/2020] [Accepted: 02/04/2020] [Indexed: 10/24/2022]
Abstract
For long time, studies on ectomycorrhiza (ECM) have been limited by inefficient expression of fluorescent proteins (FPs) in the fungal partner. To convert this situation, we have evaluated the basic requirements of FP expression in the model ECM homobasidiomycete Laccaria bicolor and established eGFP and mCherry as functional FP markers. Comparison of intron-containing and intronless FP-expression cassettes confirmed that intron-processing is indispensable for efficient FP expression in Laccaria. Nuclear FP localization was obtained via in-frame fusion of FPs between the intron-containing genomic gene sequences of Laccaria histone H2B, while cytosolic FP expression was produced by incorporating the intron-containing 5' fragment of the glyceraldehyde-3-phosphate dehydrogenase encoding gene. In addition, we have characterized the consensus Kozak sequence of strongly expressed genes in Laccaria and demonstrated its boosting effect on transgene mRNA accumulation. Based on these results, an Agrobacterium-mediated transformation compatible plasmid set was designed for easy use of FPs in Laccaria. The four cloning plasmids presented here allow fast and highly flexible construction of C-terminal in-frame fusions between the sequences of interest and the two FPs, expressed either from the endogenous gene promoter, allowing thus evaluation of the native regulation modes of the gene under study, or alternatively, from the constitutive Agaricus bisporus gpdII promoter for enhanced cellular protein localization assays. The molecular tools described here for cell-biological studies in Laccaria can also be exploited in studies of other biotrophic or saprotrophic basidiomycete species susceptible to genetic transformation.
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Affiliation(s)
- Minna Kemppainen
- Laboratory of Molecular Mycology, Institute of Basic and Applied Microbiology, Department of Science and Technology, Nacional University of Quilmes and CONICET, Bernal, Buenos Aires, Argentina.
| | - Jamil Chowdhury
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences, 901 83, Umeå, Sweden
| | - Judith Lundberg-Felten
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences, 901 83, Umeå, Sweden
| | - Alejandro Pardo
- Laboratory of Molecular Mycology, Institute of Basic and Applied Microbiology, Department of Science and Technology, Nacional University of Quilmes and CONICET, Bernal, Buenos Aires, Argentina
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9
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Nogueira-López G, Padilla-Arizmendi F, Inwood S, Lyne S, Steyaert JM, Nieto-Jacobo MF, Stewart A, Mendoza-Mendoza A. TrichoGate: An Improved Vector System for a Large Scale of Functional Analysis of Trichoderma Genes. Front Microbiol 2019; 10:2794. [PMID: 31921006 PMCID: PMC6915037 DOI: 10.3389/fmicb.2019.02794] [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: 06/20/2019] [Accepted: 11/18/2019] [Indexed: 11/13/2022] Open
Abstract
Species of the genus Trichoderma are ubiquitous in the environment and are widely used in agriculture, as biopesticides, and in the industry for the production of plant cell wall-degrading enzymes. Trichoderma represents an important genus of endophytes, and several Trichoderma species have become excellent models for the study of fungal biology and plant–microbe interactions; moreover, are exceptional biotechnological factories for the production of bioactive molecules useful in agriculture and medicine. Next-generation sequencing technology coupled with systematic construction of recombinant DNA molecules provides powerful tools that contribute to the functional analysis of Trichoderma genetics, thus allowing for a better understanding of the underlying factors determining its biology. Here, we present the creation of diverse vectors containing (i) promoter-specific vectors for Trichoderma, (ii) gene deletions (using hygromycin phosphotransferase as selection marker), (iii) protein localization (mCherry and eGFP, which were codon-optimized for Trichoderma), (iv) gene complementation (neomycin phosphotransferase) and (v) overexpression of encoding gene proteins fused to fluorescent markers, by using the Golden Gate cloning technology. Furthermore, we present the design and implementation of a binary vector for Agrobacterium-mediated transformation in Trichoderma to increase the homologous recombination rate and the generation of a novel selection marker based on carboxin resistance.
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Affiliation(s)
| | | | - Sarah Inwood
- Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand.,Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Sarah Lyne
- Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand
| | - Johanna M Steyaert
- Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand.,Lincoln Agritech Ltd, Lincoln, New Zealand
| | - Maria Fernanda Nieto-Jacobo
- Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand.,Plant & Food Research Gerald St, Lincoln, New Zealand
| | - Alison Stewart
- Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand.,Foundation For Arable Research, Templeton, New Zealand
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10
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Domka A, Rozpądek P, Ważny R, Turnau K. Mucorsp.-An endophyte of Brassicaceae capable of surviving in toxic metal-rich sites. J Basic Microbiol 2018; 59:24-37. [DOI: 10.1002/jobm.201800406] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 09/24/2018] [Accepted: 09/29/2018] [Indexed: 01/21/2023]
Affiliation(s)
- Agnieszka Domka
- Institute of Environmental Sciences; Jagiellonian University; Kraków Poland
| | - Piotr Rozpądek
- Malopolska Centre of Biotechnology; Jagiellonian University; Kraków Poland
| | - Rafał Ważny
- Malopolska Centre of Biotechnology; Jagiellonian University; Kraków Poland
| | - Katarzyna Turnau
- Institute of Environmental Sciences; Jagiellonian University; Kraków Poland
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11
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Rise of a Cereal Killer: The Biology of Magnaporthe oryzae Biotrophic Growth. Trends Microbiol 2018; 26:582-597. [PMID: 29395728 DOI: 10.1016/j.tim.2017.12.007] [Citation(s) in RCA: 141] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 12/16/2017] [Accepted: 12/20/2017] [Indexed: 01/24/2023]
Abstract
The rice blast fungus, Magnaporthe oryzae, causes one of the most destructive diseases of cultivated rice in the world. Infections caused by this recalcitrant pathogen lead to the annual destruction of approximately 10-30% of the rice harvested globally. The fungus undergoes extensive developmental changes to be able to break into plant cells, build elaborate infection structures, and proliferate inside host cells without causing visible disease symptoms. From a molecular standpoint, we are still in the infancy of understanding how M. oryzae manipulates the host during this complex multifaceted infection. Here, we describe recent advances in our understanding of the cell biology of M. oryzae biotrophic interaction and key molecular factors required for the disease establishment in rice cells.
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12
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Fones HN, Littlejohn GR. From Sample to Data: Preparing, Obtaining, and Analyzing Images of Plant-Pathogen Interactions Using Confocal Microscopy. Methods Mol Biol 2018; 1734:257-262. [PMID: 29288460 DOI: 10.1007/978-1-4939-7604-1_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This chapter describes the steps needed to inoculate host plants with a fungus of interest, and subsequently to visualize the infection using confocal microscopy. As an exemplar, we consider the interaction between wheat and the Septoria leaf blotch fungus, Zymoseptoria tritici. This method is easiest when a GFP- or other fluorophore-tagged strain of the studied fungus is available, but notes are also provided which describe possible staining techniques which may be employed if fluorescent fungus is unavailable in your system.
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13
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Goodin MM. Protein Localization and Interaction Studies in Plants: Toward Defining Complete Proteomes by Visualization. Adv Virus Res 2017; 100:117-144. [PMID: 29551133 DOI: 10.1016/bs.aivir.2017.10.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Protein interaction and localization studies in plants are a fundamental component of achieving mechanistic understanding of virus:plant interactions at the systems level. Many such studies are conducted using transient expression assays in leaves of Nicotiana benthamiana, the most widely used experimental plant host in virology, examined by laser-scanning confocal microscopy. This chapter provides a workflow for protein interaction and localization experiments, with particular attention to the many control and supporting assays that may also need to be performed. Basic principles of microscopy are introduced to aid researchers in the early stages of adding imaging techniques to their experimental repertoire. Three major types of imaging-based experiments are discussed in detail: (i) protein localization using autofluorescent proteins, (ii) colocalization studies, and (iii) bimolecular fluorescence complementation, with emphasis on judicious interpretation of the data obtained from these approaches. In addition to establishing a general framework for protein localization experiments in plants, the need for proteome-scale localization projects is discussed, with emphasis on nuclear-localized proteins.
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14
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Dallery JF, Lapalu N, Zampounis A, Pigné S, Luyten I, Amselem J, Wittenberg AHJ, Zhou S, de Queiroz MV, Robin GP, Auger A, Hainaut M, Henrissat B, Kim KT, Lee YH, Lespinet O, Schwartz DC, Thon MR, O'Connell RJ. Gapless genome assembly of Colletotrichum higginsianum reveals chromosome structure and association of transposable elements with secondary metabolite gene clusters. BMC Genomics 2017; 18:667. [PMID: 28851275 PMCID: PMC5576322 DOI: 10.1186/s12864-017-4083-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 08/21/2017] [Indexed: 11/11/2022] Open
Abstract
Background The ascomycete fungus Colletotrichum higginsianum causes anthracnose disease of brassica crops and the model plant Arabidopsis thaliana. Previous versions of the genome sequence were highly fragmented, causing errors in the prediction of protein-coding genes and preventing the analysis of repetitive sequences and genome architecture. Results Here, we re-sequenced the genome using single-molecule real-time (SMRT) sequencing technology and, in combination with optical map data, this provided a gapless assembly of all twelve chromosomes except for the ribosomal DNA repeat cluster on chromosome 7. The more accurate gene annotation made possible by this new assembly revealed a large repertoire of secondary metabolism (SM) key genes (89) and putative biosynthetic pathways (77 SM gene clusters). The two mini-chromosomes differed from the ten core chromosomes in being repeat- and AT-rich and gene-poor but were significantly enriched with genes encoding putative secreted effector proteins. Transposable elements (TEs) were found to occupy 7% of the genome by length. Certain TE families showed a statistically significant association with effector genes and SM cluster genes and were transcriptionally active at particular stages of fungal development. All 24 subtelomeres were found to contain one of three highly-conserved repeat elements which, by providing sites for homologous recombination, were probably instrumental in four segmental duplications. Conclusion The gapless genome of C. higginsianum provides access to repeat-rich regions that were previously poorly assembled, notably the mini-chromosomes and subtelomeres, and allowed prediction of the complete SM gene repertoire. It also provides insights into the potential role of TEs in gene and genome evolution and host adaptation in this asexual pathogen. Electronic supplementary material The online version of this article (10.1186/s12864-017-4083-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jean-Félix Dallery
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Thiverval-Grignon, France
| | - Nicolas Lapalu
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Thiverval-Grignon, France
| | - Antonios Zampounis
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Thiverval-Grignon, France.,Present Address: Department of Deciduous Fruit Trees, Institute of Plant Breeding and Plant Genetic Resources, Hellenic Agricultural Organization 'Demeter', Naoussa, Greece
| | - Sandrine Pigné
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Thiverval-Grignon, France
| | | | | | | | - Shiguo Zhou
- Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Marisa V de Queiroz
- Laboratório de Genética Molecular de Fungos, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Guillaume P Robin
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Thiverval-Grignon, France
| | - Annie Auger
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Thiverval-Grignon, France
| | - Matthieu Hainaut
- CNRS UMR 7257, Aix-Marseille University, Marseille, France.,INRA, USC 1408 AFMB, Marseille, France
| | - Bernard Henrissat
- CNRS UMR 7257, Aix-Marseille University, Marseille, France.,INRA, USC 1408 AFMB, Marseille, France.,Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ki-Tae Kim
- Department of Agricultural Biotechnology, Center for Fungal Genetic Resources, Seoul National University, Seoul, Korea
| | - Yong-Hwan Lee
- Department of Agricultural Biotechnology, Center for Fungal Genetic Resources, Seoul National University, Seoul, Korea
| | - Olivier Lespinet
- Laboratoire de Recherche en Informatique, CNRS, Université Paris-Sud, Orsay, France.,Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Orsay, France
| | - David C Schwartz
- Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Michael R Thon
- Instituto Hispano-Luso de Investigaciones Agrarias (CIALE), Department of Microbiology and Genetics, University of Salamanca, Salamanca, Spain
| | - Richard J O'Connell
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Thiverval-Grignon, France.
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15
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Sharpee W, Oh Y, Yi M, Franck W, Eyre A, Okagaki LH, Valent B, Dean RA. Identification and characterization of suppressors of plant cell death (SPD) effectors from Magnaporthe oryzae. MOLECULAR PLANT PATHOLOGY 2017; 18:850-863. [PMID: 27301772 PMCID: PMC6638229 DOI: 10.1111/mpp.12449] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 06/09/2016] [Accepted: 06/10/2016] [Indexed: 05/04/2023]
Abstract
Phytopathogenic microorganisms, including the fungal pathogen Magnaporthe oryzae, secrete a myriad of effector proteins to facilitate infection. Utilizing the transient expression of candidate effectors in the leaves of the model plant Nicotiana benthamiana, we identified 11 suppressors of plant cell death (SPD) effectors from M. oryzae that were able to block the host cell death reaction induced by Nep1. Ten of these 11 were also able to suppress BAX-mediated plant cell death. Five of the 11 SPD genes have been identified previously as either essential for the pathogenicity of M. oryzae, secreted into the plant during disease development, or as suppressors or homologues of other characterized suppressors. In addition, of the remaining six, we showed that SPD8 (previously identified as BAS162) was localized to the rice cytoplasm in invaded and surrounding uninvaded cells during biotrophic invasion. Sequence analysis of the 11 SPD genes across 43 re-sequenced M. oryzae genomes revealed that SPD2, SPD4 and SPD7 have nucleotide polymorphisms amongst the isolates. SPD4 exhibited the highest level of nucleotide diversity of any currently known effector from M. oryzae in addition to the presence/absence polymorphisms, suggesting that this gene is potentially undergoing selection to avoid recognition by the host. Taken together, we have identified a series of effectors, some of which were previously unknown or whose function was unknown, that probably act at different stages of the infection process and contribute to the virulence of M. oryzae.
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Affiliation(s)
- William Sharpee
- Center for Integrated Fungal Research, Department of Entomology and Plant PathologyNorth Carolina State UniversityRaleighNC27606USA
| | - Yeonyee Oh
- Center for Integrated Fungal Research, Department of Entomology and Plant PathologyNorth Carolina State UniversityRaleighNC27606USA
| | - Mihwa Yi
- Department of Plant PathologyKansas State UniversityManhattanKS66506USA
- Present address:
Noble FoundationArdmoreOK73401USA
| | - William Franck
- Center for Integrated Fungal Research, Department of Entomology and Plant PathologyNorth Carolina State UniversityRaleighNC27606USA
- Present address:
USDA‐ARS Northern Plains Agricultural Research ServiceSidneyMT59270USA
| | - Alex Eyre
- Center for Integrated Fungal Research, Department of Entomology and Plant PathologyNorth Carolina State UniversityRaleighNC27606USA
| | - Laura H. Okagaki
- Center for Integrated Fungal Research, Department of Entomology and Plant PathologyNorth Carolina State UniversityRaleighNC27606USA
- Present address:
Department of Microbiology and ImmunologyUniversity of MinnesotaMN55455USA
| | - Barbara Valent
- Department of Plant PathologyKansas State UniversityManhattanKS66506USA
| | - Ralph A. Dean
- Center for Integrated Fungal Research, Department of Entomology and Plant PathologyNorth Carolina State UniversityRaleighNC27606USA
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16
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Zhang X, Nguyen N, Breen S, Outram MA, Dodds PN, Kobe B, Solomon PS, Williams SJ. Production of small cysteine-rich effector proteins in Escherichia coli for structural and functional studies. MOLECULAR PLANT PATHOLOGY 2017; 18:141-151. [PMID: 26915457 PMCID: PMC6638209 DOI: 10.1111/mpp.12385] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 02/22/2016] [Accepted: 02/22/2016] [Indexed: 05/22/2023]
Abstract
Although the lifestyles and infection strategies of plant pathogens are diverse, a prevailing feature is the use of an arsenal of secreted proteins, known as effectors, which aid in microbial infection. In the case of eukaryotic filamentous pathogens, such as fungi and oomycetes, effector proteins are typically dissimilar, at the protein sequence level, to known protein families and functional domains. Consequently, we currently have a limited understanding of how fungal and oomycete effectors promote disease. Protein biochemistry and structural biology are two methods that can contribute greatly to the understanding of protein function. Both techniques are dependent on obtaining proteins that are pure and functional, and generally require the use of heterologous recombinant protein expression systems. Here, we present a general scheme and methodology for the production and characterization of small cysteine-rich (SCR) effectors utilizing Escherichia coli expression systems. Using this approach, we successfully produced cysteine-rich effectors derived from the biotrophic fungal pathogen Melampsora lini and the necrotrophic fungal pathogen Parastagonospora nodorum. Access to functional recombinant proteins facilitated crystallization and functional experiments. These results are discussed in the context of a general workflow that may serve as a template for others interested in understanding the function of SCR effector(s) from their plant pathogen(s) of interest.
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Affiliation(s)
- Xiaoxiao Zhang
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research CentreUniversity of QueenslandBrisbaneQld4072Australia
| | - Neal Nguyen
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research CentreUniversity of QueenslandBrisbaneQld4072Australia
| | - Susan Breen
- Research School of BiologyThe Australian National UniversityCanberraACT 0200Australia
| | - Megan A. Outram
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research CentreUniversity of QueenslandBrisbaneQld4072Australia
| | | | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research CentreUniversity of QueenslandBrisbaneQld4072Australia
| | - Peter S. Solomon
- Research School of BiologyThe Australian National UniversityCanberraACT 0200Australia
| | - Simon J. Williams
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research CentreUniversity of QueenslandBrisbaneQld4072Australia
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