Effects of High Temperature on Some Physiological Indexes in Rice Seedling Leaves and Regulations by ABA and 6-BA

In order to explore the physioloical mechanism of high temperature injury to rice,the effect of high temperature[(43.0±0.5) ℃]on some physiological indexes in seedling leaves of hybrid rice Teyou 559 and their regulations on ABA and 6-BA were studied in this paper.The results showed that the activities of superoxide dismutase(SOD) in rice seedling leaves decreased significantly under the high temperature stress.In the meanwhile the content of malondialdehyde (MDA) was increased significantly and the contents of ascorbic acid(AsA),glutathione(GSH),proline,soluble protein and soluble sugar were decreased significantly.The exogenous ABA and 6-BA could enhance effectively the ability of rice seedlings to resist high temperature stress,their physiological bases were to slow down the increasing of MDA content,and the decreasing SOD activities and the contents of AsA,GSH,proline,soluble protein and soluble sugar.