Sinorhizobium meliloti ExoR and ExoS proteins regulate both succinoglycan and flagellum production.

ABSTRACT: The production of the Sinorhizobium meliloti exopolysaccharide, succinoglycan, is required for the formation of infection threads inside root hairs, a critical step during the nodulation of alfalfa (Medicago sativa) by S. meliloti. Two bacterial mutations, exoR95::Tn5 and exoS96::Tn5, resulted in the overproduction of succinoglycan and a reduction in symbiosis. Systematic analyses of the symbiotic phenotypes of the two mutants demonstrated their reduced efficiency of root hair colonization. In addition, both the exoR95 and exoS96 mutations caused a marked reduction in the biosynthesis of flagella and consequent loss of ability of the cells to swarm and swim. Succinoglycan overproduction did not appear to be the cause of the suppression of flagellum biosynthesis. Further analysis indicated

SUBMITTER: Yao SY 

PROVIDER: S-EPMC515170 | biostudies-literature | 2004 Sep

REPOSITORIES: biostudies-literature