Exogenous sucrose can enhance tolerance of Arabidopsis thaliana seedlings to salt stress

To investigate the physiological mechanisms of salt stress mitigated by exogenous sucrose, Arabidopsis thaliana seedlings grown on Murashige and Skoog medium were treated with 3 % (m/v) sucrose combined with 75, 150, and 225 mM NaCl for 3 d. Our results show that increased salinity significantly decreased the survival rate, fresh mass, content of proteins, chlorophyll a (Chl a), and chlorophyll b (Chl b), and activities of antioxidant enzymes, whereas enhanced the content of malondialdehyde. However, the treatment with sucrose significantly enhanced salt stress tolerance in the Arabidopsis seedlings by decreasing lipid peroxidation and increasing the activities of superoxide dismutase, peroxidase, and catalase, the content of proteins, Chl a, Chl b, anthocyanins, and the transcription of genes involved in anthocyanin biosynthesis. Thus, sucrose might reduce ROS-induced oxidative damage by enhancing activities of antioxidant enzymes and the content of anthocyanins, thereby preventing membrane peroxidation and denaturation of biomolecules.