The Function Verification Of Vgb Gene In Transgentic Brassica Napus

The Vitreoscilla, an aerobic bacteria living in oxygen-barren environment, synthesizes the Vitreoscilla hemoglobin protein (vgb) which can promote microbial cells’growth and metabolic products in condition of poor oxygen. Drawing an increasing attention, the Vitreoscilla hemoglobin gene (vgb) has been transferred into marvelous varieties of plants, such as the cotton, corn, lavender and so on. These achievements have provided convincing evidences for one fact: not only can the transferred single gene of encoding VHb make the transgenic plants germinate in advance but also accelerate plants’ growth. In this paper, the Vitreoscilla hemoglobin gene has been transferred into Brassica napus with genetic engineering method, aiming at investigating the gene in the metabolic level and its influence of rapes’growth as well as identifying its function and role in the rapes’ yield and waterlogging. The main research results are as follows:Firstly, through the pollen tube pathway, the vgb gene had been transferred into rapes. Its presence in rapeseed genome obviously was identified by PCR. Secondly, Southern blot analysis had been carried on to determine the copy number of vgb in the rape genome. The results indicated that the vgb gene had been integrated into the rapeseed genome. Additionally, field experiments were well-prepared for a seriy of physiological investigations into genetically-modified rapes. The results were as follows:in comparison to conventional rapes, the germination rate of genetically-modified rapes seeds increased approximately10%, and the advance time of their germination was2days. Meanwhile, the Chlorophyll content increased approximately12%. Compared with the control group, genetically-modified rapes have exhibited a significant improvement in plants’height, leaf surface area, and seed grain weight. Moreover, submergence experiments(15days) have been conducted on transgenic oilseed rapes, with the purpose of detecting the superoxide dismutase, malondialdehyde, proline content, and agronomic traits in such conditions. The results have revealed that the genetically-modified rapes do have a remarkably-enhanced resistance to waterlogging comparing with the control group, just as anticipated.This work has confirmed that the transgenic Brassica napus, one able to express Vitreoscilla hemoglobin, can contribute to its yield-improvement and its stronger tolerance to water-logging, and lay the foundation of developing yield-improved transgenic crops furthermore. In conclusion, not only have we managed to achieve the goal of increasing the yield of transgenic plants by applying transgenic approaches, but also explore a new approach to cultivate new varieties of Brassica napus with both highly-steady-yield and resistance-to-waterlogging, which will undoubtedly promote the researches and the commercialization of other GMO crops.