Analysis Of Salt Tolerance Of Transgenic Tobacco And Transgenic Tobacco BY2 Cell With Overexpression Of Cjhppd

ρ-Hydroxyphenylpyruvate dioxigenase(HPPD,EC 1.13.11.27) catelyzes the formation of HGA fromρ-HPP. HGA is a precursor of vitamin E and plastoquinone biosynthesis. Plastoquinone is the essential cofactor for phytoene desaturase activity, while phytoene is the synthesis precursor of carotenoid. Overexpression hppd in plants can provide herbicide tolerance in the transgenic pant, and increase the synthesis of vitamins E.In this study, Cjhppd gene was introduced into tobacco by Agrobacterium tumefaciens-mediated method. PCR analysis showed that the Cjhppd gene had already integrated into the genome of tobacco cells. The contents of vitamin E were determinated and the result showed that the transgenic type of tobacco increased 2 times than the one in the wild type.The salt tolerance of tobacco plants and BY2 cells were measured. The results demonstrated that transgenic tobacco had stronger tolerance to salt than the wild type tobacco; however, the variation of proline, MDA and POD content were not the important factor that caused excellent resistance to salts. So the vitamin E content in tobacoo plants and carotenoid content in BY2 cell were detemined. The result showed that the content of vitamin E in the transgenic type was improved more effectively than that in the wild type, and vitamin E was connected directly with the salt tolerance of transgenic tobacoo. The latter result showed that content of carotenoid in transgenic tobacco BY2 cell was much higher than that in the wild type, and carotenoid was directly related to the salt tolerance of transgenic tobacoo BY2 cell. The experiment provides value reference to Cjhppd gene that in the research of salt tolerance and quality improvement of plants.