Study of natural diversity in response to a key pathogenicity regulator of Ralstonia solanacearum reveals new susceptibility genes in Arabidopsis thaliana. (23rd December 2021)

• Record Type: Journal Article
• Authors: Demirjian, Choghag; Razavi, Narjes; Desaint, Henri; Lonjon, Fabien; Genin, Stéphane; Roux, Fabrice; Berthomé, Richard; Vailleau, Fabienne
• Is Part Of: Molecular plant pathology. Volume 23:Number 3(2022)
• Page Start: 321
• Page End: 338
• Publication Date: 2021-12-23
• Subjects: Arabidopsis thaliana -- GWA mapping -- HpaP T3S4 protein -- natural accessions -- Ralstonia solanacearum -- susceptibility genes; Plant diseases -- Molecular aspects -- Periodicals; Plant-pathogen relationships -- Molecular aspects -- Periodicals; 571.936
• DOI: 10.1111/mpp.13135
• Languages: English
• ISSNs: 1464-6722

Abstract

Abstract: Ralstonia solanacearum gram‐negative phytopathogenic bacterium exerts its virulence through a type III secretion system (T3SS) that translocates type III effectors (T3Es) directly into the host cells. T3E secretion is finely controlled at the posttranslational level by helper proteins, T3SS control proteins, and type III chaperones. The HpaP protein, one of the type III secretion substrate specificity switch (T3S4) proteins, was previously highlighted as a virulence factor on Arabidopsis thaliana Col‐0 accession. In this study, we set up a genome‐wide association analysis to explore the natural diversity of response to the hpaP mutant of two A. thaliana mapping populations: a worldwide collection and a local population. Quantitative genetic variation revealed different genetic architectures in both mapping populations, with a global delayed response to the hpaP mutant compared to the GMI1000 wild‐type strain. We have identified several quantitative trait loci (QTLs) associated with the hpaP mutant inoculation. The genes underlying these QTLs are involved in different and specific biological processes, some of which were demonstrated important for R . solanacearum virulence. We focused our study on four candidate genes, RKL1, IRE3, RACK1B, and PEX3, identified using the worldwide collection, and validated three of them as susceptibility factors. Our findings demonstrate that the study of the natural diversity of plant response to a R . solanacearum mutant in a key regulator of virulence is an original and powerful strategy to identify genes directly or indirectly targeted by the pathogen. Abstract : A genome‐wide association study to explore the natural diversity of Arabidopsis thaliana in response to the Ralstonia solanacearum hpaP mutant: an original strategy to identify plant genes targeted by the pathogen.