Overexpression of TaSRK2C1, a Wheat SNF1-Related Protein Kinase 2 Gene, Increases Tolerance to Dehydration, Salt, and Low Temperature in Transgenic Tobacco

Abstract

Protein phosphorylation–dephosphorylations are major signaling events induced by osmotic stress in plants. In this study, a wheat SNF1-related protein kinase 2 (SnRK2) gene, TaSRK2C1, was functionally characterized. The results from the sequence analysis showed that TaSRK2C1 contains conserved domains typified in SnRK2 protein kinases, including the ATP binding site, N-myristoylation site, protein kinase-activating signature, and transmembrane-spanning region. The transcripts of TaSRK2C1 in roots were induced by treatments of dehydration, high salinity, low temperature, and exogenous abscisic acid, which suggest its potential roles relative to osmotic stress signal transductions. The ectopic expression of TaSRK2C1 in tobacco significantly up-regulated the expression levels of three putative central regulators, namely, RD29a, DREB1A, and DREB2, which are involved in responding to osmotic stresses. Thus, higher levels of free proline and soluble carbohydrates in transgenic plants were detected, and conferred tolerance to high salinity, dehydration stress, and low temperature in plants. The overall results in this study indicate that TaSRK2C1 have important functions in plant response and adaptation to osmotic stresses via mediation of signal transductions initiated by distinct abiotic stresses. Manipulating TaSRK2C1 toward improving the osmotic-stress tolerance in crop plants is feasible.