AUTHOR=Zou Qian , Luo Sha , Wu Hetao , He Donglan , Li Xiaohua , Cheng Guojun TITLE=Corrigendum: A GMC Oxidoreductase GmcA Is Required for Symbiotic Nitrogen Fixation in Rhizobium leguminosarum bv. viciae JOURNAL=Frontiers in Microbiology VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.774051 DOI=10.3389/fmicb.2021.774051 ISSN=1664-302X