The plant signal salicylic acid shuts down expression of the vir regulon and activates quormone-quenching genes in Agrobacterium.

ABSTRACT: Agrobacterium tumefaciens is capable of transferring and integrating an oncogenic T-DNA (transferred DNA) from its tumor-inducing (Ti) plasmid into dicotyledonous plants. This transfer requires that the virulence genes (vir regulon) be induced by plant signals such as acetosyringone in an acidic environment. Salicylic acid (SA) is a key signal molecule in regulating plant defense against pathogens. However, how SA influences Agrobacterium and its interactions with plants is poorly understood. Here we show that SA can directly shut down the expression of the vir regulon. SA specifically inhibited the expression of the Agrobacterium virA/G two-component regulatory system that tightly controls the expression of the vir regulon including the repABC operon on the Ti plasmid. We provide evidence

SUBMITTER: Yuan ZC 

PROVIDER: S-EPMC1905925 | biostudies-literature | 2007 Jul

REPOSITORIES: biostudies-literature