College of Life Science, Shandong Agricultural University, Tai'an 271018, PR China.
Plant Physiol Biochem. 2013 Sep;70:150-8. doi: 10.1016/j.plaphy.2013.05.014. Epub 2013 Jun 1.
The salt overly sensitive pathway has an important function in plant salinity tolerance. The enhancer of SOS3-1 (ENH1) participates in a new salinity stress pathway with SOS2 but without SOS3. To investigate the physiological effects and functional mechanism of ENH1 under salt stress, ENH1 was isolated from tomato and overexpressed in tobacco. Under salt stress, the sprouting percentage, fresh weight, and dry weight of transgenic plants were higher than those of wild-type (WT) plants. Under salt stress, the chlorophyll content, net photosynthetic rate, and maximal photochemical efficiency of PSII in transgenic plants decreased more slowly than those in WT plants. The overexpression of LeENH1 in tobacco excluded Na(+) from the cytosol and retained high K(+) levels in the cytosol to reestablish ion homeostasis. Higher thylakoid-bound ascorbate peroxidase activity and lower reactive oxygen species levels were found in transgenic plants under salt stress.
盐过度敏感途径在植物耐盐性中具有重要功能。增强子 SOS3-1 的增强子（ENH1）与 SOS2 参与新的盐胁迫途径，但没有 SOS3。为了研究 ENH1 在盐胁迫下的生理效应和功能机制，从番茄中分离出 ENH1 并在烟草中过表达。在盐胁迫下，转基因植株的发芽率、鲜重和干重均高于野生型（WT）植株。在盐胁迫下，转基因植株的叶绿素含量、净光合速率和 PSII 最大光化学效率下降速度均比 WT 植株慢。LeENH1 在烟草中的过表达将 Na(+) 从细胞质中排除，并在细胞质中保持高 K(+) 水平以重新建立离子平衡。在盐胁迫下，转基因植株的类囊体结合抗坏血酸过氧化物酶活性更高，活性氧水平更低。
