| In a survey of candidate genes located in the salinity tolerance locus of soybean, we identified a putative glutathione-S-transferase (GST) gene (GmGSTL1) which was up-regulated in response to salt treatment. Phylogenetic analyses revealed that this putative GST belongs to the Lambda class, a plant-specific group with unknown functions. We expressed GmGSTL1 in heterologous systems, including tobacco BY-2 cells and Arabidopsis thaliana, to test its ability to protect cell/plant against salinity stress. Compare to the wild type control, we observed a marked reduction of ROS accumulation in transgenic cells under salt treatment, and their survival rate was also improved. Similarly, expression of GmGST1 in transgenic A. thaliana also alleviated stress symptoms under salt treatment. To further address the possible protective mechanisms of GmGSTL1, we identified two candidate flavonoid interactants (quercetin and kaemferol) of the GmGSTL1 protein from soybean leaf extract. Exogenous application of quercetin could reduce salinity-induced ROS accumulation in BY-2 cells and leaf chlorosis in A. thaliana.. |
