Effect of UV-B radiation and a supplement of CaCl_2 on carotenoid biosynthesis in germinated corn kernels

摘要

This study investigated effects of UV-B radiation and CaCl2 on the enhancement of carotenoid content in germinated corn kernels. UV-B radiation and CaCl2 treatments were effective for promoting both carotenoid content and antioxidant activity. Furthermore, the carotenoid content was greater when under the combined treatments of UV-B radiation and CaCl2. Activities of superoxide dismutase and peroxidase were enhanced but malondialdehyde content was weakened by UV-B radiation plus CaCl2 compared to the UV-B radiation only. The mRNA expression of PSY, PDS, ZDS, LCYB, LCYE, BCH1, CYP97C genes involved in the carotenoid biosynthesis pathway showed different patterns in UV-B radiation and CaCl2 treatments. This reveals that the UV-B radiation can increase carotenoid content and antioxidant enzyme activity. Moreover, CaCl2 can further improve carotenoid content and reduce photooxidative damage caused by UV-B radiation.