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A two‐component regulatory system VfmIH modulates multiple virulence traits in Dickeya zeae
Author(s) -
Lv Mingfa,
Hu Ming,
Li Peng,
Jiang Zide,
Zhang LianHui,
Zhou Jianuan
Publication year - 2019
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.14233
Subject(s) - biology , virulence , operon , mutant , two component regulatory system , histidine kinase , gene , response regulator , genetics , gene cluster , promoter , locus (genetics) , microbiology and biotechnology , regulator gene , regulation of gene expression , gene expression
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.