Functions of the Sinorhizobium meliloti LsrB Substrate-Binding Domain in Oxidized Glutathione Resistance, Alfalfa Nodulation Symbiosis, and Growth

被引：0

作者：

Zeng, Shuang ^{[1
]}

Wang, Sunjun ^{[1
]}

Lin, Zhiyin ^{[1
]}

Jin, Huibo ^{[1
]}

Li, Hongbo ^{[1
]}

Yu, Huilin ^{[1
]}

Li, Jiaze ^{[1
]}

Yu, Liangliang ^{[1
]}

Luo, Li ^{[1
]}

机构：

[1] Shanghai Univ, Ctr Plant Sci, Sch Life Sci, Shanghai Key Lab Bioenergy Crops, Shanghai 200444, Peoples R China

来源：

JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY | 2024年 / 72卷 / 43期

关键词：

LysR; oxidized glutathione; rhizobium; symbiotic nodulation; cysteine residue; EXPRESSION; GENES; DIFFERENTIATION; VECTORS; OXYR;

D O I：

10.1021/acs.jafc.4c07925

中图分类号：

S [农业科学];

学科分类号：

09 ;

摘要：

To successfully colonize legume root nodules, rhizobia must effectively evade host-generated reactive oxygen species (ROS). LsrB, a redox regulator from Sinorhizobium meliloti, is essential for symbiosis with alfalfa (Medicago sativa). The three cysteine residues in LsrB's substrate domain play distinct roles in activating downstream redox genes. The study found that LsrB's substrate-binding domain, dependent on the cysteine residue Cys146, is involved in oxidized glutathione (GSSG) resistance and alfalfa nodulation symbiosis. LsrB homologues from other rhizobia, with Cys172/Cys238 or Cys146, enhance GSSG resistance and complement lsrB mutant's symbiotic nodulation. Substituting amino acids in Azorhizobium caulinodans LsrB with Cys restores lsrB mutant phenotypes. The lsrB deletion mutant shows increased sensitivity to NCR247, suggesting an interaction with host plant-derived NCRs in alfalfa nodules. Our findings reveal that the key cysteine residue in the LsrB's substrate domain is vital for rhizobium-legume symbiosis.

引用

页码：23908 / 23916

页数：9