Sinorhizobium meliloti can live as a soil saprophyte and can engage in a nitrogen-fixing symbiosis with plant roots. To succeed in such diverse environments, the bacteria must continually adjust gene expression. Transcriptional plasticity in eubacteria is often mediated by alternative sigma (σ) factors interacting with core RNA polymerase.
View Article and Find Full Text PDFscreen for novel symbiotic mutants of the nitrogen-fixing legume symbiont Sinorhizobium meliloti uncovered a crucial role for the putative response regulator FeuP in the symbiotic infection process. Transcriptome analysis shows that FeuP controls the transcription of at least 16 genes, including ndvA, which encodes an ATP-dependent exporter of cyclic beta glucans. Loss of feuP function gives rise to traits associated with cyclic beta glucan biosynthetic defects, including poor growth and motility under hypoosmotic conditions, and the inability to invade plant tissue during the early stages of symbiotic infection.
View Article and Find Full Text PDFThe soil-dwelling alpha-proteobacterium Sinorhizobium meliloti engages in a symbiosis with legumes: S. meliloti elicits the formation of plant root nodules where it converts dinitrogen to ammonia for use by the plant in exchange for plant photosynthate. To study the coordinate differentiation of S.
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