Multi-walled carbon nanotubes enhanced the antioxidative system and alleviated salt stress in grape seedlings

To enhance the salt resistance of seeds and seedlings for grapes under salt stress, multi-walled carbon nanotubes (MWCNTs) at 30, 60, 90, 150, and 180 μg/mL, respectively, were used to treat gape seedlings, and the seed germination and physiological characteristics grape seedlings were studied. MWCNTs at 90 μg/mL exhibited the best results, increased root length and germination rate compared with other concentrations. Moreover, MWCNTs at 90 μg/mL mostly decreased the content of MDA in leaves and increased the activities of superoxide (SOD), peroxidase (POD), and catalase (CAT). At the same time, it increased the activities of dehydroascorbate reductase (DHAR), ascorbate peroxidase (APX), glutathione-S-transferase (GT), and glutathione reductase (GR). MWCNTs treatment also maintained the scavenging activity of DPPH· and increased the ratios of GSH:GSSG and AsA:DHA. These results suggested that MWCNTs with the appropriate concentration of 90 μg/mL could significantly enhance the reducing ability through direct and indirect antioxidant systems (the AsA-GSH cycle) and maintain a high antioxidant capacity of grape seedlings under salt stress.