Poly-3-hydroxybutyrate (PHB) supports survival and reproduction in starving rhizobia.

摘要: The carbon that rhizobia in root nodules receive from their host powers both N2 fixation, which mainly benefits the host, and rhizobium reproduction. Rhizobia also store energy lipid poly-3-hydroxybutyrate (PHB), may enhance survival when they are limited, either or soil between hosts. There can be a conflict of interest legumes over rate PHB accumulation, due to metabolic tradeoff fixation accumulation. To quantify carbon-limited rhizobia, populations genetically uniform with high vs. low (confirmed by flow cytometry) were generated fractionating Sinorhizobium meliloti via density gradient centrifugation, harvesting cells at early late stationary phase. These starved for 165 days. use during starvation was highly predictive initial reproduction long-term population maintenance. Cultured S. accumulated enough triple size starved, persist c. 150 days before fell below its value. During first 21 nodule growth, undifferentiated within alfalfa support significant increases starvation.