Revealing Signaling Pathway of Novel Two-component System TsiRS in Regulating Virulence of Pseudomonas Syringae

Project: Research

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Pseudomonas syringae, the leading cause of crop diseases world-wide, uses the type III secretion system (T3SS) to invade host plants. The T3SS of plant pathogenic bacteria is induced in both plant and minimal media (MM) growth conditions. Although a number of components that regulate the T3SS gene expression cascade have been identified, how bacteria sense the environmental conditions and further transduce the signal(s) to the known regulatory components remains largely unknown. We recently found a novel two-component system (TCS) called TsiRS that is a major regulator of the T3SS in P. syringae. In our previous studies, we found that TsiS negatively regulated a group of T3SS genes, including hrpR, which encodes a key regulator of the T3SS. We also identified that succinate regulates the expression of tsiS and its downstream gene argF. We propose a novel signalling pathway of succinate-TsiRS-hrpR-T3SS, the verification of which is the focus of the proposal. Genetic and biochemical characterisation of the TsiRS pathway is the first step toward identifying signals to which the T3SS responds, and toward the development of new strategies for disease control based on T3SS manipulation. Our long-term goal is to leverage the outcomes of the studies proposed herein to develop improved therapies against P. syringae infection in agricultural crops. 


Project number9042938
Grant typeGRF
Effective start/end date1/01/21 → …