Overexpression ofPtSOS2Enhances Salt Tolerance in Transgenic Poplars.
Protein kinases are major signal transduction factors that have a central role in mediating acclimation to environmental changes in eukaryotic organisms. In this study, we cloned and identified three salt overly sensitive 2 (SOS2) genes in the woody plantPopulus trichocarpa, designated asPtSOS2.1,PtSOS2.2, andPtSOS2.3, which were transformed into hybrid poplar clone T89 (Populus tremula×Populus tremuloidesMichx clone T89) mediated byAgrobacterium tumefaciens. Southern and northern blot analyses verified that the three genes integrated into the plant genome, and were expressed at a stable transcription level. Meanwhile, overexpression of all threePtSOS2genes did not retard the growth of plants under normal conditions. Instead, it promoted growth in both agar-medium and soil conditions in response to salinity stress. Under salt stress, overexpression ofPtSOS2.1,PtSOS2.2, andPtSOS2.3increased the concentrations of proline and photosynthetic pigments, and the relative water content (RWC), and the activity of antioxidant enzymes, and decreased the malondialdehyde (MDA) concentrations in transgenic lines compared to the control. These results suggest that overexpression ofPtSOS2plays a significant role in improving the salt tolerance of poplars, reducing the damage to membrane structures, and enhancing osmotic adjustment and antioxidative enzyme regulation under salt stress.
Jie
J
Zhou
Jingjing
J
Wang
Yufang
Y
Bi
Like
L
Wang
Luozhong
L
Tang
Xiang
X
Yu
Misato
M
Ohtani
Taku
T
Demura
Qiang
Q
Zhuge
Overexpression; Populus; PtSOS2; Salt tolerance; SnRK