Cloning The Gene Inhabiting Tobacco Axillary Bud And Its Genetic Transformation On Tobacco

Decapitation of the top bud in certain period was an important process in tabacco plantation. When the bud is decapitated , plenty of the side buds will sproud out, which will reduce the quality of the tabacco . So it is important to take the side buds away in time. The production cost of tobacco leaves increases because of the labor consuming needed in the Decapitation and bud releasing. Using chemical methors to control the axillary buds helps a lot, but this mesure is still not so satisfying. With the development of biotechnich , gene engineering has been used widly to improve the breed, and many breeds of transgenitic tobacco were successful breed one by one. Therefore, it is possible to controle the side bud by an gene engenering way.Many genes has been found to play roles in the growth of side buds among which SPS gene from Arobodopsis ,the NtPSA from tabacco and the PSAD1 from pea were chosed by us for the translate the tabacco. We cloned all of the three gene and linked to the pBI121 vector in construction of three plant expression vector. Moreover, for knocking out the maker gene in the next generation, we also constructed a double right—border (DRB) binary vector system.In the transgenitic plant, because the purpose gene expressed stably and continually by constructive promoter, so the substance and energy of inner cell were exhausted. While the purpose gene expressed only when the inducible promoter accepted the inducible signal, which has not much effect on the plant physiological activity. So, the CaMV35S promoter of pBI121 vector was replaced with wound inducible promoter POD in this research.The Is mutant of tomato and las mutant of Arabidopsis thaliana can not upgrowth the side bud because of not forming the axillary meristem ,and the rice moc mutant also can not tiller. The research indicated that the LS, LAS, MOC three genes could promote the growth of side bud, and they had several segment homologous AA sequences. According to homologous AA sequences of the three genes, we have cloned a cDNA fragment of key gene TLS which was important to the growth of tobacco side bud by degenerate primer, then linked the fragment to pKANIBAL in construction of RNAi vector, otherwise ,The RT-PCR showed that the expression of TLS gene had been detected in the side bud, root and flower bud.We have obtained the transgenic plant after transferring plant expression vector with wound inducible promoter into tobacco; while no transgenic plant was obtained through transferring RNAi vector into tobacco, so the result showed that TLS gene maybe was the key function to the forming of bud.