Responses of Antioxidative Protection to Varying Drought Stresses Induced by Micro-Ecological Fields on Desert C4 and C3 Plants in Northwest China

Desert plants are exposed to a combination of environmental stress conditions, including water deficit, high temperature and high irradiance. We focused on antioxidative protection systems of C4 desert plant Haloxylon ammodendron and C3 desert plant Hedysarum scoparium within arid dune ecosystem with artificial controlling water availability. The activities of antioxidative enzymes (SOD, POD and CAT) in H. scoparium were significantly higher than those in H. ammodendron under the same conditions; the activities of antioxidative enzymes in leaflets of H. scoparium were higher than those in rachis. With the increasing drought, the accumulation of the antioxidant (flavonoids) was increased in H. ammodendron. However, the amount of flavonoids was decreased in H. scoparium. Flavonoid contents in the leaflets and rachis of H. scoparium were higher than those in assimilating shoots of H. ammodendron. In conclusion, H. ammodendron and H. scoparium applied different strategies of protection against water deficit, high irradiance stress and high temperature stress during daily process in summer, and inducing high activities of antioxidative enzymes in C3 desert plant was an important safeguard to live in desert condition, and the advantages of C4 metabolism of H. ammodendron was that it was not easily influenced physiologically to the same level of stress as H. scoparium. [Gong C, Ning P, Bai J. Responses of Antioxidative Protection to Varying Drought Stresses Induced by MicroEcological Fields on Desert C4 and C3 Plants in Northwest China. Life Sci J 2012; 9(4):2006-2016] (ISSN: 10978135). http://www.lifesciencesite.com.301