OsMSR2, a novel rice calmodulin-like gene, confers enhanced salt tolerance in rice (Oryza sativa L.)

OsMSR2 is a novel calmodulin-like gene in rice. Previous study has been demonstrated that OsMSR2 was a cold, drought and heat-inducible gene. However, the role of OsMSR2 in rice stress response is still unclear. To reveal the function of OsMSR2 involved in stress response, the expression pattern and effects of overexpression of OsMSR2 on salt stress were analyzed in rice. Quantitative real-time RT-PCR analysis showed that OsMSR2 was rapidly induced by salt stress. Histochemical GUS staining assay revealed that OsMSR2 was mainly expressed in root, leaf, seedling, lamina joint, base of stem and spikelet. Transgenic rice plants with overexpression of OsMSR2 showed more tolerant to salt stress, with 18.2% survival rate for the wild type and 51.3% for transgenic plants at the end of the salt treatment. In OsMSR2-overexpressing transgenic plants, expression levels of some stress-related genes were also altered compared to wild type plants under salt condition. The more accumulated proline and soluble sugars and decreased electrolyte leakage were also observed in transgenic rice compared to wild type plants under salt stress. These results indicate that OsMSR2 plays important roles in salt stress tolerance in rice, and is useful in developing transgenic crops with enhanced tolerance to salt stress.