Effects of He-Ne Laser on Antioxidant Systems of Wheat Seedlings Exposed to Ultraviolet-B Radiation

The seedlings of wheat(Jinmai 8)were exposed to He-Ne laser irradiation with 5 mW·mm^-2 power density,enhanced UV-B radiation(10.08 kJ·m^-2·d^-1)and the combined treatment of He-Ne laser irradiation and enhanced UV-B radiation for 5 days.Changes on the production rate of superoxide radicals,activity of gutathione reductase(GR)and ascorbate peroxidase(APX);content of malondialdehyde(MDA),ascorbic acid(AsA)and carotenoid(Car)were measured to test the repair role of He-Ne laser irradiation.The results showed that He-Ne laser irradiation on the wheat seedlings resulted in decreasing of the production rate of superoxide radicals,the content of MDA,AsA and Car,the activity of GR and APX enhanced.It suggested that those changes in production rate of superoxide radicals,MDA,GR,APX,AsA and Car were responsible for the capacity of repair in the wheat.Therefore,the damage of wheat seedlings induced by enhanced UV-B radiation on antioxidant systems can be repaired partly by He-Ne laser irradiation.