Journal article
Functional Analyses of the Diels-Alderase Gene sol5 of Ascochyta rabiei and Alternaria solani Indicate that the Solanapyrone Phytotoxins Are Not Required for Pathogenicity
Molecular plant-microbe interactions, Vol.2015(1), pp.1-15
01/2015
Handle:
https://hdl.handle.net/2376/112486
PMID: 27839072
Abstract
Ascochyta rabiei and Alternaria solani, the causal agents of Ascochyta blight of chickpea (Cicer arietinum) and early blight of potato (Solanum tuberosum), respectively, produce a set of phytotoxic compounds including solanapyrones A, B, and C. Although both the phytotoxicity of solanapyrones and their universal production among field isolates have been documented, the role of solanapyrones in pathogenicity is not well understood. Here, we report the functional characterization of the sol5 gene, which encodes a Diels-Alderase that catalyzes the final step of solanapyrone biosynthesis. Deletion of sol5 in both Ascochyta rabiei and Alternaria solani completely prevented production of solanapyrones and led to accumulation of the immediate precursor compound, prosolanapyrone II-diol, which is not toxic to plants. Deletion of sol5 did not negatively affect growth rate or spore production in vitro, and led to overexpression of the other solanapyrone biosynthesis genes, suggesting a possible feedback regulation mechanism. Phytotoxicity tests showed that solanapyrone A is highly toxic to several legume species and Arabidopsis thaliana. Despite the apparent phytotoxicity of solanapyrone A, pathogenicity tests showed that solanapyrone-minus mutants of Ascochyta rabiei and Alternaria solani were equally virulent as their corresponding wild-type progenitors, suggesting that solanapyrones are not required for pathogenicity.
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Details
- Title
- Functional Analyses of the Diels-Alderase Gene sol5 of Ascochyta rabiei and Alternaria solani Indicate that the Solanapyrone Phytotoxins Are Not Required for Pathogenicity
- Creators
- Wonyong Kim - 1 Department of Plant PathologyChung-Min Park - 2 Department of Chemistry, andJeong-Jin Park - 3 Institute of Biological Chemistry, Washington State University, Pullman 99164, U.S.A.; andHajime O Akamatsu - 1 Department of Plant PathologyTobin L Peever - 1 Department of Plant PathologyMing Xian - 2 Department of Chemistry, andDavid R Gang - 3 Institute of Biological Chemistry, Washington State University, Pullman 99164, U.S.A.; andGeorge Vandemark - 4 United States Department of Agriculture-Agricultural Research Service, Grain Legume Genetics and Physiology Research Unit, Washington State University, PullmanWeidong Chen - 4 United States Department of Agriculture-Agricultural Research Service, Grain Legume Genetics and Physiology Research Unit, Washington State University, Pullman
- Publication Details
- Molecular plant-microbe interactions, Vol.2015(1), pp.1-15
- Academic Unit
- Chemistry, Department of; Plant Pathology, Department of; Biological Chemistry, Institute of
- Publisher
- United States
- Identifiers
- 99900548270101842
- Language
- English
- Resource Type
- Journal article