Asymmetric redundancy of soybean Nodule Inception (NIN) genes in root nodule symbiosis

• DOI: 10.1093/plphys/kiab473
• Publication Date: 2021-10-08T20:27:17Z
• Authors: Mengdi Fu; Jiafeng Sun; Xiaolin Li; Yuefeng Guan; Fang Xie
• Keywords: Nodule (geology); Root (linguistics)

Abstract Nodule Inception (NIN) is one of the most important root nodule symbiotic genes as it required for both infection and organogenesis in legumes. Unlike legumes with a sole NIN gene, there are four putative orthologous soybean (Glycine max). Whether how these contribute to soybean–rhizobia interaction remain unknown. In this study, we found that all GmNIN induced by rhizobia conserved CE CYC binding motifs their promoter regions expression formation process. By generation multiplex Gmnin mutants, Gmnin1a nin2a nin2b triple mutant nin1b quadruple displayed similar defects formation, Gmnin2a produced fewer nodules but hyper phenotype compared wild type (WT), while double nodulated WT. Overexpression GmNIN1a, GmNIN1b, GmNIN2a, GmNIN2b reduced numbers after inoculation, GmNIN1b overexpression having weakest effect. addition, or GmNIN2b, not malformed pseudo-nodule-like structures without inoculation. conclusion, play functionally redundant yet complicated roles nodulation. although expressed at comparable level other homologs, plays minor role symbiosis. Our work provides insight into understanding asymmetrically function soybean.