Analysis of Antioxidant Characteristics and Related Gene Expression Profiles of Rice Drought-Tolerance Lines Derived from Embryo-Soaking with Alternanthera philoxeroides DNA Solution
Résumé
Drought is one of major abiotic stress limiting rice stable production. In the
study, four rice cultivars, IAPAR9 (upland rice cultivar), H8 and H10 (drought-
tolerance 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