OsJRL40, a Jacalin-Related Lectin Gene, Promotes Salt Stress Tolerance in Rice

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.

Genome-Wide and Transcriptome Analysis of Jacalin-Related Lectin Genes in Barley and the Functional Characterization of HvHorcH in Low-Nitrogen Tolerance in Arabidopsis

“…Most functionally known JRLs in subgroup 1 are involved in agglutinating activity [35,50,52,56], which demonstrated that proteins from the same subgroup may display similar roles. Meanwhile, two members in subgroup 7, Orysata and HvHorcH, both confer a tolerance to salt stress [31,51], and the member OsJRL40 in subgroup 10 also positively regulated salt stress tolerance [30]. Both OsJAC1 and TaJA1 in subgroup 1 were associated with pathogen resistance [21,49,50], and TaJRLL1 in subgroup 6 was also involved in pathogen resistance [16].…”

“…JRL are widely distributed in plants and are found in many species, including Arabidopsis, rice, wheat, maize, barley, Sorghum bicolor, and Musa acuminata [2]. Several of them have been demonstrated to be involved in plant growth regulation and stress responses [3,10,28,30,31,54]. Owing to their essential roles, the identification and characterization of JRL gene families and their expression profiles in response to abiotic stresses have been performed at the genome-wide level in several plant species, such as rice, wheat, and moso bamboo [2,3,10].…”

“…The potential functions of HvJRLs were predicted based on their functionally known homologs in the same subgroup (Figure 5). Numerous members in subgroups 1, 6, 7, 10, and 11 were involved in the response to biotic and abiotic stresses, such as pathogen resistance [16,21,49,50], response to hormones [26,27], salt tolerance [30,31,51], and drought tolerance [25]. The members of subgroup 1 might also be associated with beta-glucosidase aggregation [35,52], vernalization signaling, and spike development regulation [11,12].…”

“…In addition, some JRLs play roles in response to abiotic stresses, such as salt [22,23], drought [24,25], and hormones [12,26,27]. In recent years, many studies have showed that the JRL family genes play important roles in salt stress response, including Orysata and OsJRL40 in rice [28][29][30], HvHorcH in barley [31], a PeJRL in poplar (Populus euphratica) [32], and several TaJRLs in wheat [3]. Nitrogen deficiency is a common problem in agricultural production worldwide.…”

Abiotic Stress in Rice: Visiting the Physiological Response and Its Tolerance Mechanisms

“…Increases antioxidant enzymatic activities and maintains the balance of Na + /K + during salinity stress. Manages rice's salt stress by regulating the expression of genes responsible for transporting Na + /K + , as well as genes involved in salt-responsive transcription factors and proteins [322] OsSAPK4…”