小麦蛋白激酶TaSnRK2.8抵御干旱及盐分逆境功能研究

he non-fermentation protein kinase of sucrose SnRK2 family members regulate protein activity and downstream gene transcription through its role in phosphorylating modification by participating in a variety of signal transduction pathways, by which to mediate metabolic processes and to exert roles in plant stress response. In this study, TaSnRK2.8,a gene belonging to the SnRK2 family in wheat, was subjected to functional characterization for its role in mediating plant drought and salt stress response. The results showed that the TaSnRK2.8 protein contains a catalytic domain of serine/threonine kinase and multiple phosphorylation sites. The transcript abundance of TaSnRK2.8 was up-regulated in roots and leaves under drought and salt treatments, indicating that this gene is involved in responding to osmotic stresses. Compared with the wild-type control (WT), the sense and antisense transgenic lines of TaSnRK2.8 changed significantly on phenotypes under drought and salt treatments, showing that the growth condition of the sense line (Sen 1) increased plant dry weight and leaf area whereas the antisense line (Anti 1) decreased the plant dry biomass and leaf area. Observation of stomatal closure characteristics of transgenic lines revealed that compared with WT, Sen 1 showed faster while Anti 1 slower on stomatal closing rates under drought and salt treatments. In addition, compared with WT, the photosynthetic efficiency of transgenic sense lines were improved and its contents of soluble protein, soluble sugar and proline were increased, and its related parameters of cellular reactive oxygen species (ROS) homeostasis-related parameters were improved. These results indicated that TaSnRK2.8 can improve the plant photosynthetic mechanism osmoregulation substance biosynthesis, stomata movement, and cell active oxygen homeostasis by regulating physiological processes and biochemical metabolic pathways. It therefore enhance plant drought and salt stresses.