A two‐component regulatory system VfmIH modulates multiple virulence traits in Dickeya zeae. Issue 6 (28th March 2019)

• Record Type: Journal Article
• Authors: Lv, Mingfa; Hu, Ming; Li, Peng; Jiang, Zide; Zhang, Lian‐Hui; Zhou, Jianuan
• Is Part Of: Molecular microbiology. Volume 111:Issue 6(2019)
• Page Start: 1493
• Page End: 1509
• Publication Date: 2019-03-28
• Subjects: Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.14233
• Languages: English
• ISSNs: 0950-382X

Abstract

Summary: Bacterial pathogen Dickeya zeae strain EC1 produces antibiotics‐like phytotoxins called zeamines, which are major virulence determinants encoded by the zms gene cluster. In this study, we identified a zeamine‐deficient mutant with a Tn5 insertion in a gene designated as vfmI encoding a two‐component system (TCS) sensor histidine kinase (HK), which is accompanied by vfmH encoding a response regulator (RR) at the same genetic locus. Domain analysis shows this TCS is analogous to the VfmIH of D. dadantii, with typical characteristics of sensor HK and RR, respectively, and sharing the same operon. Deletion of either vfmI or vfmH resulted in decreased production of zeamines and cell wall degrading enzymes (CWDEs), and alleviated virulence on rice seeds and potato tubers. In D. dadantii 3937, VfmH was shown to bind to the promoters of vfmA and vfmE, while in D. zeae EC1, VfmH could bind to the promoters of vfmA, vfmE and vfmF . RNA‐seq analysis of strain EC1 and its vfmH mutant also showed that the TCS positively regulated a range of virulence genes, including zms, T1SS, T2SS, T3SS, T6SS, flagellar and CWDE genes. Abstract : VfmIH is a conserved TCS in Dickeya, modulating virulence traits such as production of zeamines and cell wall degrading enzymes, synthesis and transport of Vfm QS signal, cell motility and biofilm formation in strain EC1, through regulation of the transcripts of numerous pathogenicity related geness.