Phytotoxin Production by<i>Diaporthe phaseolorum</i>var.<i>caulivora,</i>the Causal Organism of Stem Canker of Soybean

Lalitha, B. S.; Snow, J. P.; Berggren, G. T.

doi:10.1094/phyto-79-499

Cited by 19 publications

(9 citation statements)

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“…All garlic cultivars and other crops tested were susceptible to the pathogen. Similar host specificity of toxins from other pathogens have been demonstrated using nonhosts and hosts of Pyrenophora graminea (Haegi and Porta-Puglia 1995), P. teres (Smedegard-Petersen 1977), Rhizoctonia solani (Vidhyasekaran et al 1997), S. versicarium (Singh et al 1999), Septoria glycies (Song et al 1993) and Diaporthe phatolorum (Lalitha et al 1989). The toxin was non-host specific but exhibited differential phytotoxicity towards various plants.…”

Section: Discussionsupporting

confidence: 62%

Host range and phytotoxicity of Stemphylium solani, causing leaf blight of garlic (Allium sativum) in China

Zheng

Hsiang

et al. 2008

Eur J Plant Pathol

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Since 2004, a new leaf blight disease on garlic of high severity has been observed in Dangyang County, Hubei province, China. Initial symptoms consisted of multiple, small, irregular to oval, white leaf spots, which enlarge to produce sunken purple lesions, sometimes surrounded by a bright yellow margin. As the disease progressed, lesions expanded and merged, resulting in withering of leaf tips. After isolation and pathogenicity testing, the causal agent of leaf blight of garlic was identified as Stemphylium solani from cultural and morphological characteristics, and subsequent analysis of the internal transcribed spacer region of ribosomal DNA. When fungal plugs of two S. solani isolates were inoculated onto 11 garlic cultivars and 20 other crop species, leaf spots appeared on all inoculated plants, but two garlic cultivars (Qingganruanye and Ruanruanye) and three crop species (Capsicum annuum, Brassica napus and Amaranthus mangostanus) showed the smallest leaf spots. In cross-inoculation experiments, no indications of host specificity were observed, but S. solani isolated from garlic was generally the most virulent on five plant species, while the isolate from leek (Allium odorum) was generally the least virulent. Toxicity testing of the crude culture filtrates indicated that garlic isolates produced toxin(s) that were not heat-labile and induced different levels of phytotoxicity toward various garlic cultivars and crops.

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Section: Discussionsupporting

confidence: 62%

Host range and phytotoxicity of Stemphylium solani, causing leaf blight of garlic (Allium sativum) in China

Zheng

Hsiang

et al. 2008

Eur J Plant Pathol

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“…During sunflower infection, D. helianthi produces the polyketidic phytotoxin phomozin and related toxins, and purified phomozin causes disease symptoms [ 27 ]. Interestingly, the possible involvement of a phytotoxin produced by D. caulivora during SCC development has been previously reported [ 66 ].…”

Section: Resultsmentioning

confidence: 99%

Comparative genomics of plant pathogenic Diaporthe species and transcriptomics of Diaporthe caulivora during host infection reveal insights into pathogenic strategies of the genus

et al. 2022

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Background Diaporthe caulivora is a fungal pathogen causing stem canker in soybean worldwide. The generation of genomic and transcriptomic information of this ascomycete, together with a comparative genomic approach with other pathogens of this genus, will contribute to get insights into the molecular basis of pathogenicity strategies used by D. caulivora and other Diaporthe species. Results In the present work, the nuclear genome of D. caulivora isolate (D57) was resolved, and a comprehensive annotation based on gene expression and genomic analysis is provided. Diaporthe caulivora D57 has an estimated size of 57,86 Mb and contains 18,385 predicted protein-coding genes, from which 1501 encode predicted secreted proteins. A large array of D. caulivora genes encoding secreted pathogenicity-related proteins was identified, including carbohydrate-active enzymes (CAZymes), necrosis-inducing proteins, oxidoreductases, proteases and effector candidates. Comparative genomics with other plant pathogenic Diaporthe species revealed a core secretome present in all Diaporthe species as well as Diaporthe-specific and D. caulivora-specific secreted proteins. Transcriptional profiling during early soybean infection stages showed differential expression of 2659 D. caulivora genes. Expression patterns of upregulated genes and gene ontology enrichment analysis revealed that host infection strategies depends on plant cell wall degradation and modification, detoxification of compounds, transporter activities and toxin production. Increased expression of effectors candidates suggests that D. caulivora pathogenicity also rely on plant defense evasion. A high proportion of the upregulated genes correspond to the core secretome and are represented in the pathogen-host interaction (PHI) database, which is consistent with their potential roles in pathogenic strategies of the genus Diaporthe. Conclusions Our findings give novel and relevant insights into the molecular traits involved in pathogenicity of D. caulivora towards soybean plants. Some of these traits are in common with other Diaporthe pathogens with different host specificity, while others are species-specific. Our analyses also highlight the importance to have a deeper understanding of pathogenicity functions among Diaporthe pathogens and their interference with plant defense activation.

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“…The toxinic theory is supported by the evidence that other phytopathogenic species related to the genus Phomopsis produce toxic metabolites involved in pathogenesis [ 58 – 60 ]. For a disease caused by a Phomopsis species affecting soybean, similar to stem canker of sunflower, the possible involvement of a phytotoxin was also implied [ 61 ]. Polyketide synthases have been reported as important virulence factors in other several phytopathogenic fungi such as C. heterostrophus [ 3 ], Colletotrichum lageniarum [ 62 ] and A. alternata [ 63 ].…”

Section: Discussionmentioning

confidence: 99%

Polyketide synthases of Diaporthe helianthi and involvement of DhPKS1 in virulence on sunflower

et al. 2018

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BackgroundThe early phases of Diaporthe helianthi pathogenesis on sunflower are characterized by the production of phytotoxins that may play a role in host colonisation. In previous studies, phytotoxins of a polyketidic nature were isolated and purified from culture filtrates of virulent strains of D. helianthi isolated from sunflower. A highly aggressive isolate (7/96) from France contained a gene fragment of a putative nonaketide synthase (lovB) which was conserved in a virulent D. helianthi population.ResultsIn order to investigate the role of polyketide synthases in D. helianthi 7/96, a draft genome of this isolate was examined. We were able to find and phylogenetically analyse 40 genes putatively coding for polyketide synthases (PKSs). Analysis of their domains revealed that most PKS genes of D. helianthi are reducing PKSs, whereas only eight lacked reducing domains. Most of the identified PKSs have orthologs shown to be virulence factors or genetic determinants for toxin production in other pathogenic fungi. One of the genes (DhPKS1) corresponded to the previously cloned D. helianthi lovB gene fragment and clustered with a nonribosomal peptide synthetase (NRPS) -PKS hybrid/lovastatin nonaketide like A. nidulans LovB. We used DhPKS1 as a case study and carried out its disruption through Agrobacterium-mediated transformation in the isolate 7/96. D. helianthi DhPKS1 deleted mutants were less virulent to sunflower compared to the wild type, indicating a role for this gene in the pathogenesis of the fungus.ConclusionThe PKS sequences analysed and reported here constitute a new genomic resource that will be useful for further research on the biology, ecology and evolution of D. helianthi and generally of fungal plant pathogens.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-017-4405-z) contains supplementary material, which is available to authorized users.

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Phytotoxin Production byDiaporthe phaseolorumvar.caulivora,the Causal Organism of Stem Canker of Soybean

Cited by 19 publications

References 0 publications

Host range and phytotoxicity of Stemphylium solani, causing leaf blight of garlic (Allium sativum) in China

Host range and phytotoxicity of Stemphylium solani, causing leaf blight of garlic (Allium sativum) in China

Comparative genomics of plant pathogenic Diaporthe species and transcriptomics of Diaporthe caulivora during host infection reveal insights into pathogenic strategies of the genus

Polyketide synthases of Diaporthe helianthi and involvement of DhPKS1 in virulence on sunflower

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