Regulation of bacterial virulence by two component signal transduction systems
A. PANDEY (1) (1) CSIR-Central Institute of Medicinal and Aromatic Plants, India

Two component signal transduction systems (TCSTSs) are one of the most prevalent ways by which bacteria sense, respond, and adapt to various changes in their environment. TCSTS is basically formed by a membrane bound histidine kinase sensor and a cytoplasmic response regulator. We are interested in understanding the role of TCSTSs in plant-microbe interaction using Rice-Xanthomonas oryzae pv. oryzae (Xoo) pathosystem. Genome sequence analysis revealed that Xoo (the causal agent of bacterial blight) is equipped with large repertoire of TCSTSs. I am focusing on the ColRS system essential for Xoo virulence. The predicted protein products of colS (a sensor kinase) and colR (a response regulator) are 450 and 246 amino acids, respectively. The ColS has a conserved H251 residue, which is predicted to be auto phosphorylated upon receiving a stimulus. The ColR receiver domain has a conserved D72 residue, which is predicted to be phosphorylated by the ColS. The ColR contains DNA binding region as output domain belonging to OmpR family, which can execute a diverse array of functions by controlling expression of downstream target genes.  The colS and colR mutants were generated for detailed characterization of the ColRS system. Microarray analysis revealed that large subsets of Xoo genes are regulated by the ColRS system. These genes are required in various physiological pathways. This study suggests that the ColRS system regulates a complex signaling network that controls virulence.

Abstract Number: P9-293
Session Type: Poster