Control of nitrogen fixation and ammonia excretion in Azorhizobium caulinodans.

ABSTRACT: Due to the costly energy demands of nitrogen (N) fixation, diazotrophic bacteria have evolved complex regulatory networks that permit expression of the catalyst nitrogenase only under conditions of N starvation, whereas the same condition stimulates upregulation of high-affinity ammonia (NH3) assimilation by glutamine synthetase (GS), preventing excess release of excess NH3 for plants. Diazotrophic bacteria can be engineered to excrete NH3 by interference with GS, however control is required to minimise growth penalties and prevent unintended provision of NH3 to non-target plants. Here, we tested two strategies to control GS regulation and NH3 excretion in our model cereal symbiont Azorhizobium caulinodans AcLP, a derivative of ORS571. We first attempted to recapitulate previous work where

SUBMITTER: Haskett TL 

PROVIDER: S-EPMC9249168 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature