The Function Of Vgb Gene In Transgenic Insect-resistant Cotton

There is a sensitive system controlling and responding to the level of oxygen in the plants. Thus, it is important to maintain a steady level oxygen to avoid the unnecessary loss energy and to ensure survival. A novel genetic response to enhance oxygen metabolism has been observed in the microbial world: The obligate aerobic, Gram-negative bacterium Vitreoscilla synthesizes elevated quantities of a novel homodimeric hemoglobin (VHb) in oxygen-limited cultivations. Expression of VHb in Escherichia coli increases specific growth rate, final cell density, and cloned reporter enzyme expression in oxygen-limited cultures. This study had developed vgb (Vitreoscilla hemoglobin gene) transgenic cotton,we studied the influence to plant metabolic level and growth.This work showed the function both yield improvement and water logging resistance.of vgb gene in insect-resistant cotton.In this study we proved that vgb gene in insect-resistant cotton. containing and expressing the vgb gene and Bt gene respectively, PCR and Southern blot analysis confirmed their transgenic status: PCR result was that there was no specific band appeared in negative control, but a specific band similar to positive control was amplified from the test sample; Southern blot result was there two vgb-specific hybridizing bands. At the same time we found that there were more vgb insecticidal protein at seedling stage than at summer stage of cotton life. Finally, we tested that there were Bt insect-resistant proteins of different levels in both bivalent insect-resistant cotton leaf and transgenic Bt pest-resistant cotton leaf by Bt-Cry1Ab/1Ac rapid paper strips test method. Fluorescence real-time quantitative PCR, the relative expression level of vgb gene in a different transgenic cotton Lane is detected, and had difference expression.The transgenic cotton plants had showed obvious cotton bollworm resistance. Simultaneously, we also found their geminating speeded up, leave chlorophyll content improved by 15-20%, flowering date moved up 3-5 day ,the boll number increased significantly,but the seed-cotton weight per-boll is no change . The yield increased significantly, thereinto ,the transgenic cotton 1 lint weight seed increased 134.5%, cotton yield increased 150.2%.Carry on the inundation experiment during seedling and flowering period, Observe Cotton yield and its yield components were affected significantly by different cotton Species. Examine several physiology index signs of SOD, CAT, MAD, PRO etc,provrd vgb Gene in Transgenic Insect-resistant Cotton have water logging resistance.This work had proved that the transgenic cotton expressing Vitreoscilla hemoglobin showed both yield improvement and water logging resistance. We also noticed that chlorophyll content was a good mark to judge the expression of Vitreoscilla hemoglobin in transgenic plant. This work had laid a research foundation for developing yield improvement transgenic crops in further.We manage to reach the goal of increasing the yield of transgenic plants and cultivate new plant vatities with pest-resistance by applying transgenic approaches, and eventually in the hope of cultivating new varities of crops with both highly-steady-yield and pest-resistance. will undoubtedly promote the studies and the commercialization of the GMO crops.