The Physiological Protective Effects Of NO Response To The Enhanced UV-B Radiation In Nostoc Commune And Chlamydomonas Sajao

The protective roles of NO were studied under the enhanced ultraviolet-B radiation in Chlamydomonas sajao and Nostoc commune. The change of the growth and the activities antioxidant enzyme such as SOD, CAT, POD and the value of chlorophyll fluorescence (Fv/Fm) were estimated. The ultrastructure and microstructure of the cell are evaluated. The main results are as follows:(1)The resultes suggested that the growth were inhibited by the UV-B radiated (0.2W/m2) in 11d culture. It was redued the inhibited effects induced by UV-B treated with SNP.(2) The damage of UV-B radiation to the two kinds of algae was due to the lipid peroxidation in their cells, the content of ROS increase significantly. The SOD, CAT, POD activities had the same trend due to large number of ROS formation. The activities were boosted trested with SNP. It is shown that NO could reduce the stress of UV-B radiation.(3) The contents of the pigments was reduced by UV-B radiation in the cells. After 6d treatment of UV-B radiation, the value of Fv/Fm decreased to zero. Fv/Fm was restored 95% compared with the control.(4) Under UV-B radiation, the diameter and volume of Chlamydomonas cells decreased, with a increase in fat particles and polysaccharide particles in algal cells compared with the control. The cells of Nostoc turn out yellowing, cracking, and even death under UV radiation. The results suggested that NO alleviate the damage induced by the UV-B radiation.(5) After UV-B radiation, algal protein content, chlorophyll a, carotenoid content and polysaccharide content is decreased by UV-B radiation. The contents were raised treated with NO.