OhrR is a central transcriptional regulator of virulence in Dickeya zeae. (24th October 2021)

• Record Type: Journal Article
• Authors: Lv, Mingfa; Chen, Yufan; Hu, Ming; Yu, Qinglin; Duan, Cheng; Ye, Sixuan; Ling, Jinfeng; Zhou, Jianuan; Zhou, Xiaofan; Zhang, Lianhui
• Is Part Of: Molecular plant pathology. Volume 23:Number 1(2022)
• Page Start: 45
• Page End: 59
• Publication Date: 2021-10-24
• Subjects: biofilm -- c‐di‐GMP -- Dickeya zeae -- motility -- pathogenicity -- zeamines; Plant diseases -- Molecular aspects -- Periodicals; Plant-pathogen relationships -- Molecular aspects -- Periodicals; 571.936
• DOI: 10.1111/mpp.13141
• Languages: English
• ISSNs: 1464-6722

Abstract

Abstract: Dickeya zeae is the causal agent of rice foot rot disease. The pathogen is known to rely on a range of virulence factors, including phytotoxin zeamines, extracellular enzymes, cell motility, and biofilm, which collectively contribute to the establishment of infections. Phytotoxin zeamines play a critical role in bacterial virulence; signalling pathways and regulatory mechanisms that govern bacterial virulence remain unclear. In this study, we identified a transcriptional regulator OhrR (organic hydroperoxide reductase regulator) that is involved in the regulation of zeamine production in D. zeae EC1. The OhrR null mutant was significantly attenuated in its virulence against rice seed, potato tubers and radish roots. Phenotype analysis showed that OhrR was also involved in the regulation of other virulence traits, including the production of extracellular cellulase, biofilm formation, and swimming/swarming motility. DNA electrophoretic mobility shift assay showed that OhrR directly regulates the transcription of key virulence genes and genes encoding bis‐(3′–5′)‐cyclic dimeric guanosine monophosphate synthetases. Furthermore, OhrR positively regulates the transcription of regulatory genes slyA and fis through binding to their promoter regions. Our findings identify a key regulator of the virulence of D. zeae and add new insights into the complex regulatory network that modulates the physiology and virulence of D. zeae . Abstract : OhrR is crucial for regulatory of virulence factors production and pathogenicity, and regulates SlyA and Fis to control the expression of downstream virulence genes.