A Study On Transformation Of The TT1 Gene Into Rice Mediated By Agrobacterium

Rice(Oryza sativa L.) is an important worldwide cereal crop.More than half of the population in China depends on rice as its principle staple food.With the development of industry and the exacerbation of the greenhouse effect,rice will be not able to grow normally under the rising temperature,the pollens will become abnormal and the pollens' activity will go down.The high temperature finally results in the reduction of the yield and the falling off in quality.It's very important to improve the ability of rice's heat-tolerance.There are few rice varieties which can endure high temperature,or even though they have good ability of heat-tolerance,the agronomic traits are normally bad.So,transferring the heat-tolerant gene into rice varieties to improve the heat tolerance of rice will be of great importance to solve the problem of reducing arable land and increasing population.TT1 is a single gene which was cloned from Brassica napus,it's the only gene ever discovered in the world that can enhance the thermo-tolerance of rape through the expression of a single gene.It will be an effect way to breed high yield and quantity rice varieties which can endure high temperature if the gene can express normally in rice.In this study,TT1 gene was transferred into rice varieties through Agrobacterium tumefaciens-mediated transformation to testify the function of TT1 in rice.The results were as follows:1.By comparison of induction efficiency of different maturity seeds of Nipponbare,the young seeds induced more callus than full-green seeds and full-yellow seeds,the induction efficiency of full-yellow seeds were lowest.The pollution frequency of the young seeds were most serious while the full-yellow seeds were the lowest.2 The optimum time of co-cultivation for the callus derived from immature embryos was 2.5 days while the callus derived from the mature embryos was 3 days.22℃was the optimum co-cultivation temperature both for the callus from immature embryos and mature embryos. The differentiation rate of immature embryos was higher than mature embryos.3 The selection reagent for immature embryos callus and mature embryos callus indicated that the optimum selection concentration of hygromycin for both of these calli was 50 mg/L.4 The PCR assay of the regenerated seedlings proved that transgenic plants containing foreign gene TT1 were obtained.The RT-PCR assay further proved that TT1 was expressed on RNA level.5 By comparison of the ability of the heat-tolerance of transgenic plants and non-genetically modified plants,it showed that non-genetically modified plants died in 2 hours when the temperature was 50℃,while transgenic plants didn't die until the temperature went up to 57℃.