Role of quorum sensing in Sinorhizobium meliloti-Alfalfa symbiosis.

ABSTRACT: The ExpR/Sin quorum-sensing system of the gram-negative soil bacterium Sinorhizobium meliloti plays an important role in the establishment of symbiosis with its host plant Medicago sativa. A mutant unable to produce autoinducer signal molecules (sinI) is deficient in its ability to invade the host, but paradoxically, a strain lacking the quorum-sensing transcriptional regulator ExpR is as efficient as the wild type. We compared the whole-genome expression profile of the wild-type strain with strains missing one of the quorum-sensing regulatory components to identify genes controlled by the ExpR/Sin system throughout the different phases of the bacterial growth cycle, as well as in planta. Our analyses revealed that ExpR is a highly versatile regulator with a unique ability to show differen

SUBMITTER: Gurich N 

PROVIDER: S-EPMC2698488 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature