Corrigendum: A GMC Oxidoreductase GmcA Is Required for Symbiotic Nitrogen Fixation in Rhizobium leguminosarum bv. viciae - Zou, Qian; Luo, Sha; Wu, Hetao; He, Donglan; Li, Xiaohua; Cheng, Guojun (Frontiers in Microbiology, 2021)