| China is a country of serious lack of water resources. Drought is a major limited factor of agricultural development in many areas. Rice, one of the most important grain crops in China, its production is highly vulnerable to drought, because of large volume of water demand for the growth and development. Research on the interaction between seed maturation and dehydration provided a theoretical support for using transgenic technology to improve the resistance of rice. Finally let drought resistance gene at the right time, proper position, the appropriate gene expression rate to play the right role. Then the interference from exogenous genes on crop will be reduced.Drought resistance and seed maturity are controlled by abscisic acid metabolism. The previous studies have found that there are two paths in gramineae plants during seed development: one for glucose metabolism and the grouting process, another for the process of dehydration in maturity. In this paper we use barley gene chip to find the relationship between these genes. By analysis of homologous sequences, we select the two downstream ABA-dependent putative genes: OsDREB1 (LOC_Os09g20350.1) and 0sSNF2 (LOC_ Os08g37800.1 ) . Through mature embryo and immature embryo transgenic technology, we obtained 7 over expression OsDREB1 transgenic plants, 22 OsDREB1 RNAi transgenic plants, which is promoted by CaMV35S promoter, 29 OsDREB1 in situ expression transgenic plants, 43 OsSNF2 RNAi transgenic plants, which is promoted by OsSNF2 gene promoter, 41 transgenic plants which contain fusion protein of GFP and GUS without functional gene. After the following experiment on these transgenic plants we obtained the following conclusions.1. The results of phenotypic analysis with the T0 and T1 generations of transgenic plants are as follows. OsDREB1 super-expression plants were difficult to regeneration and smaller. In situ expression plants analysis indicated that OsDREB1 were constitutive expression in anthers and seedling basal stem, with the drought stress increased the OsDREB1 expression. OsDREB1 inhibit expression plant in the simulated drought stress behaved more sensitive and significant weakened in drought tolerance. The analysis of transgenic plant stomata number and water loss rate shows, OsSNF2 inhibited transgenic plants had more Stomatal number compared with other transgenic plants and with relatively faster rate of water loss. OsSNF2 inhibition T0 generation transgenic plants on behalf of the vegetative growth are more vigorous than other transgenic plants. OsSNF2 inhibition T1 generation germination rate is higher than the rate of non-transgenic Nipponbare. ABA germination experiment indicated that OsSNF2 inhibition plants are more sensitive to ABA.2. After the treatment with ABA, NaCl in the seedling stage, the treatment with drought in the boot stage, and the treatment with ABA in the germination process, Nipponbare treatment experiments obtained gene expression profiles. Research confirmed the OsSNF2 and OsDREB1 are drought-, high-salt-, ABA- induced genes. But the mechanism of OsDREB1 and DREB2A is different. OsDREB1 induced by ABA in leaves, embryo and endosperm expression pattern shows little difference in the process of seed germination. DREB2A do not dependent on ABA in leaves, and induced by ABA in Embryo, its expression in the endosperm is much higher than the embryo. SNF1 and OsSNF2 have similar mechanism, its expression in the endosperm is much higher than the embryo, 0sSNF2 induced by ABA in embryo.3. Through gene expression analysis, the preliminary study shows that the drought resistance mechanism and glucose metabolism at the transcriptional level are parallel, non-interfering. OsDREB1 expression is no significant changes after inhibition OsSNF2 gene expression. Also OsSNF2 expression is no significant changes after inhibition OsDREB1 gene expression. But after OsDREB1 gene over expression, both SNF1 and OsSNF2 decreased. Combined with the phenotypic of plants, over expression OsDREB1 interpreted the body's metabolism and inhibited glucose metabolism, which made the lower level expression of OsSNF2 & SNF1. OsDREB1 RNAi and OsSNF2 RNAi transgenic plants are more sensitive to drought stress, which gene expressions increased more quickly.4. In this paper, the optimization of the suitable induction conditions for rice mature embryo-derived callus are discussed. The Nipponbare and HuHan 3 mature embryo-derived callus inducing factors experiments were under different temperatures, light and medium conditions. The results indicated that the best mature embryo-derived callus induction conditions are under the conditions of the organic doubling medium, 32℃, 12h light / 12h dark light. The affecting conditions of the weight of callus ordered by the importance were the temperature, the medium factors, the light and dark conditions. Nipponbare inducing rate is higher at higher temperature, HuHan 3 inducing rate is higher at lower temperature. Callus weight and the inducing rates in the Organic doubling medium and the ferric salt doubling medium were significantly superior to conventional media. Callus area variations of higher temperature had larger differences than lower temperature. Callus weight and the inducing rates between Nipponbare and HuHan 3 are significantly different, but they all came to the same conclusion. A highly efficient transformation system mediated by Agrobacterium was established, it would lay the foundation for the study of gene function in rice.
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