Analysis of Antioxidant Characteristics and Related Gene Expression Profiles of Rice Drought-Tolerance Lines Derived from Embryo-Soaking with Alternanthera philoxeroides DNA Solution
Drought is one of major abiotic stress limiting rice stable production. In the study, four rice cultivars, IAPAR9 (upland rice cultivar), H8 and H10 (droughttolerance variant lines derived from 6527 embryo-soaked with Alternanthera philoxeroides DNA solution) and 6527 (ordinary rice cultivar), were used to study the antioxidant characteristics of drought-resistant varieties by superoxide dismutase (SOD) activity, peroxidase (POD) activity, malondialdehyde (MDA) content and their related gene expression profiles. The results showed that the SOD activity, POD activity and MDA content were increased significantly under drought stress, while decreased in the yield and its related traits such as seed setting ratio, 1000-grain weight and grain number per panicle. The SOD and POD activities in drought-tolerant rice (H8, H10 and IAPAR9) were significantly higher than those in drought-sensitive 6527. Less MDA content was produced in drought-tolerant rice (H8, H10 and IAPAR9) than sensitive 6527. The yield of H8 was significantly higher than that of other cultivars, and the seed setting ratio and 1000-grain weight from those with drought-tolerant were significantly higher than that of sensitive 6527. After drought stress, there were 11 genes related to antioxidant progress whose expression profiles changed significantly between H8 and 6527. These results suggested that drought tolerant cultivars maybe subdue harms from the peroxidation by inducing the express of related genes of antioxidant process, further increasing the SOD activity and POD activity. Thus, their enhancement of drought resistance could maintain the normal growth and development under drought stress and achieve maximum photosynthate storage.
Yan Li, Jia Xiang, Yaqing Wang, Liyuan Zheng, Yawei Fan, Yunfeng Li, and Fangming Zhao