The <i>Sinorhizobium meliloti</i> LpxXL and AcpXL Proteins Play Important Roles in Bacteroid Development within Alfalfa

Abstract

Free-living Sinorhizobium meliloti lpxXL and acpXL mutants lack lipid A very-long-chain fatty acids (VLCFAs) and have reduced competitiveness in alfalfa. We demonstrate that LpxXL and AcpXL play important but distinct roles in bacteroid development and that LpxXL is essential for the modification of S. meliloti bacteroid lipid A with VLCFAs.