The plasma membrane is critical in sensing, interpreting, and transducing environmental signals. In the present study, we characterized an Oryza sativa salt-responsive little protein 1 (OsSRLP1) in rice, which encodes a plasma membrane localized protein containing 54 amino acid residues. Expression of OsSRLP1 was detected in various rice tissues and was significantly induced by low temperature, drought, and salt. Overexpression of OsSRLP1 in rice improved free proline content and modulated ion balance under salt stress, which resulted in enhanced salt tolerance. Compared to wild-type rice, overexpression of OsSRLP1 inhibited seed germination under normal conditions. Interestingly, OsSRLP1 expression was up-regulated in ABL5-Like1 deficiency mutant abl1 compared to wild-type rice under salt treatment. Moreover, it was observed that overexpression of OsSRLP1 led to the dwarfism phenotype, which was correlated to the OsSRLP1 expression level in transgenic rice. In conclusion, OsSRLP1 is a little membrane protein conferring salt tolerance by modulating the ion balance and proline accumulation in rice.

质膜对于感测，解释和转换环境信号至关重要。在本研究中，我们表征了水稻中稻米盐反应小蛋白1（OsSRLP1）的特征，该蛋白编码包含54个氨基酸残基的质膜定位蛋白。在水稻的各种组织中均检测到OsSRLP1的表达，并且低温，干旱和盐分会明显诱导OsSRLP1的表达。水稻中OsSRLP1的过表达改善了盐胁迫下的游离脯氨酸含量并调节了离子平衡，从而提高了耐盐性。与野生型水稻相比，在正常条件下，OsSRLP1的过量表达抑制了种子发芽。有趣的是，OsSRLP1与盐处理下的野生型水稻相比，ABL5-Like1缺乏突变体abl1的表达上调。此外，观察到OsSRLP1的过表达导致矮化表型，这与转基因水稻中OsSRLP1的表达水平相关。总之，OsSRLP1是一种膜蛋白，可通过调节水稻中的离子平衡和脯氨酸的积累来赋予耐盐性。