Qinmei Gao, Xiaolin Yin, Feng Wang, Shuchang Hu, Weihao Liu, Liangbi Chen, Xiaojun Dai, Manzhong Liang.

Int. J. Mol. Sci.; 2023 Apr 18; 24(8):7441. doi: 10.3390/ijms24087441.

Abstract

High salinity is a major stress factor affecting the quality and productivity of rice (Oryza sativa L.). Although numerous salt tolerance-related genes have been identified in rice, their molecular mechanisms remain unknown. Here, we report that OsJRL40, a jacalin-related lectin gene, confers remarkable salt tolerance in rice. The loss of function of OsJRL40 increased sensitivity to salt stress in rice, whereas its overexpression enhanced salt tolerance at the seedling stage and during reproductive growth. β-glucuronidase (GUS) reporter assays indicated that OsJRL40 is expressed to higher levels in roots and internodes than in other tissues, and subcellular localization analysis revealed that the OsJRL40 protein localizes to the cytoplasm. Further molecular analyses showed that OsJRL40 enhances antioxidant enzyme activities and regulates Na⁺-K⁺ homeostasis under salt stress. RNA-seq analysis revealed that OsJRL40 regulates salt tolerance in rice by controlling the expression of genes encoding Na⁺/K⁺ transporters, salt-responsive transcription factors, and other salt response-related proteins. Overall, this study provides a scientific basis for an in-depth investigation of the salt tolerance mechanism in rice and could guide the breeding of salt-tolerant rice cultivars.

See https://pubmed.ncbi.nlm.nih.gov/37108614/

Figure 1 Analysis of OsJRL40 amino acid sequence and phylogenetic relationship. (A) Amino acid sequence alignment of OsJRL40, barley LEM2 (AAM18206), TaJRLL1 (ADP37001), AtJRL33 (NP_001030711), and AtNSP4 (NP_188262). Dark shading indicates conserved residues, and invariant residues are marked with lowercase letters. Asterisks indicate mannose-binding sites in the Heltuba protein. ‘*’ represents the mannose-binding site. (B) Analysis of the evolutionary relationship between OsJRL40 and JRLs in other species (rice, Arabidopsis, wheat, maize, and soybean). The phylogenetic tree was constructed using the neighbor-joining method in MEGA 7.