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In this study, Arabidopsis wild-type Col-0, mutant rgs1-2, overexpressing 35S: RGS1-N, 35S: RGS1-C as a material, by mutant analysis, construction of transgenic plants, and other technologies, using molecular biology, biochemistry and other methods to study the N-terminal and C-terminal domain AtRGS1 protein's role in the Arabidopsis glucose and ABA signal transduction pathways. The following major findings: 1 TOPO cloning constructed 35S: and RGS1 was-N, 35S: RGS1 was-C Overexpression of the transgenic plants. Cloned AtRGS1 gene N-terminal, C-terminal cDNA by TOPO Cloning of CaMV 35S promoter, GFP as a report gene, containing the fusion gene 35S: RGS1 was-N-GFP, and 35S: of RGS1 was-C-GFP plant expression carrier. Dip transformation method using Agrobacterium tumefaciens 35S: RGS1 was-N-GFP, 35S: of RGS1 was-C-GFP fusion gene into rgs1-2 mutant plants were obtained after antibiotic selection, roots fluorescence observation and the GFP gene by PCR, transformation successful positive plants. 2, the use of mutant analysis Research AtRGS1 protein N-terminal and C-terminal domain in the Arabidopsis glucose and ABA signal transduction pathway and its regulation mechanism. The results show that: (1) rgs1-2 seed germination inhibition of glucose insensitive, while the 35S: RGS1 was-N, 35S: RGS1 was-C seed the performance of the ultra-sensitive, which 35S: RGS1-N seeds are the most sensitive. Inhibition of four genotypes of seed germination of mannose showed no differences. Show that this inhibition is independent of the sugar osmotic stress, but caused by glucose-mediated signal transduction pathway. The hexokinase inhibitor NAG processing weakened mannose inhibitory effect on seed germination, and inhibit the germination of glucose has no effect, indicating that glucose inhibition of seed germination is not dependent on hexose kinase pathway. (2) rgs1-2 seed germination: RGS1 was-N, the ABA Min, 35S, 35S: RGS1 was-C seed performance for ultra-sensitive, 35S: RGS1 was-N seeds most sensitive. Showed that over-expression of the AtRGS1-N, AtRGS1-C complementary ABA-sensitive phenotype of rgs1-2, increases seed sensitivity to ABA. (3) glucose and ABA treatment results show that there are superimposed effect of glucose and ABA inhibition of seed germination. Fluridone and glucose processing results Fluridone can reduce glucose inhibit the effect of seed germination. Glucose to inhibit germination by increasing endogenous ABA content. (4) rgs1-2 seedlings taproot was significantly longer than Col, 35S: RGS1 was-N, 35S: of RGS1 was-C taproot significantly shorter than Col rgs1-2. rgs1-2, 35S: RGS1-N and 35S: RGS1 was-C taproot growth on glucose and ABA response showed the same trend, the lowest sensitivity of rgs1-2, followed by 35S: RGS1 was-C, 35S: RGS1 was sensitive-N the highest. That AtRGS1 gene mutations and overexpression changes the metabolism of sugar and ABA sensitivity of the regulatory role. (5) the plant level, rgs1-2 from leaf water loss rate significantly faster than the Col and 35S: RGS1 was-N, 35S: of RGS1 was-C was significantly lower than Col. Show that over the the expression AtRGS1-N AtRGS1-C can reduce the rate of water loss of leaves, enhanced drought tolerance. (6) under drought stress conditions, rgs1-2 water potential was significantly lower than Col the 35S: RGS1 was-N, 35S: of RGS1 was-C water potential was significantly higher than the Col rgs1-2. Rgs1-2 water-retention capacity is weak, and the 35S: RGS1 was-N, 35S: RGS1 was-C has strong water retention capacity, able to maintain higher leaf water potential under drought stress. Accordingly, Col. rgs1 of ABA content low switch transgenic lines 35S: RGS1 was-N The 35S: RGS1 was-C of ABA content was significantly higher than the Col-2 rgs1. Showed that over-expression AtRGS1 N-terminal and C-terminal domain enhances the ability of the Arabidopsis response to drought stress.
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