Salt, cold and heavy metals are major factors limiting crop productivity and quality. Here we report the role of OsSMP1 (stress membrane protein) of rice in response to abiotic stress. Gene chip analysis showed the expression level OsSMP1 was significantly increased in rice under cold, drought and heat treatment. The results of RT-PCR showed that the relative expression level of the OsSMP1 gene was up-regulated in rice under ABA, high salt and cold treatments. There were some cis-elements upstream of OsSMP1 that regulate ABA, low temperature and drought. The result of OsSMP1pro: GUS transgenic plant is consistent with that of the gene chip and RT-PCR. OsSMP1-GFP fusion protein expression showed that OsSMP1 was mainly localized on the cell membrane. Overexpression of OsSMP1 improves rice tolerance to salt, cold and heavy metal (CdCl₂ and CuSO₄) stress but increases rice sensitivity to abscisic acid. These results imply that OsSMP1 is a positive regulator of rice tolerance to salt, cold and heavy metal via an ABA-dependent pathway and is potential for improving rice tolerance to abiotic stress.

盐，冷金属和重金属是限制作物生产力和质量的主要因素。在这里，我们报告水稻OsSMP1（应激膜蛋白）在应对非生物胁迫中的作用。基因芯片分析表明，在寒冷，干旱和热处理条件下，水稻中OsSMP1的表达水平明显升高。RT-PCR结果表明，在ABA，高盐和冷处理下，水稻中OsSMP1基因的相对表达水平上调。OsSMP1上游有一些顺式元素调节ABA，低温和干旱。OsSMP1pro：GUS转基因植物的结果与基因芯片和RT-PCR的结果一致。OsSMP1-GFP融合蛋白的表达表明OsSMP1主要定位在细胞膜上。OsSMP1的过表达提高了水稻对盐，冷和重金属（CdCl ₂和CuSO ₄）胁迫的耐受性，但增加了水稻对脱落酸的敏感性。这些结果表明，OsSMP1是水稻通过ABA依赖性途径对盐，冷金属和重金属的耐受性的正调节剂，并且具有提高水稻对非生物胁迫的耐受性的潜力。