Bradyrhizobium diazoefficiens Requires Chemical Chaperones To Cope with Osmotic Stress during Soybean Infection
Raphael Ledermann, Barbara Emmenegger, Jean‐Malo Couzigou, Nicola Zamboni, Patrick Kiefer, Julia A. Vorholt, Hans‐Martin Fischer
Abstract
-soybean symbiosis is of great agricultural significance and serves as a model system for fundamental research in bacterium-plant interactions. While detailed molecular insight is available about mutual recognition and early nodule organogenesis, our understanding of the host-imposed conditions and the physiology of infecting rhizobia during the transition from a free-living state in the rhizosphere to endosymbiotic bacteroids is currently limited. In this study, we show that the requirement of the rhizobial general stress response (GSR) during host infection is attributable to GSR-controlled biosynthesis of trehalose. Specifically, trehalose is crucial for an efficient symbiosis by acting as a chemical chaperone to protect rhizobia from osmostress during host infection.