Analysis On Characters Of Transgenic Rice With OsbHLH1 Or AhCMO Gene

Salt stress and low temperature are common abiotic stresses in rice production. In order to breed new rice varieties with salt and low temperature tolerance and improve theeir stress tolerance in rice, the characters of transgenic sinica (japonica) restorer line Huai C17 with Bar-OsbHLH1 or Bar-AhCMO gene and their progenies were studied. The main results were as follows:(1) The regenerated plants of transgenic T1 generation were smeared with 1 g/L of glufosinate on the leaves and the results showed that the regenerated plants were resistant to glufosinate, which indicated that the Bar gene have expressed in rice. T2 and T3 generation of transgenic plants at three complete leaves plus one young leaf stage were sprayed 0.75 g/L of glufosinate and the results showed that the Bar gene expressed normally also. The lines homozygous in Bar gene were selected out because all individuals of these lines with Bar-OsbHLH1gene in T3 generation were alive after sprayed 0.75 g/L of glufosinate.(2) Transgenic plants were detected by PCR and Southern blotting and the results showed that the foreign genes had integrated into the rice genome. T3 generation of transgenic lines were detected by RT-PCR and real-time fluorescence quantitative PCR, the results showed that the foreign genes (OsbHLHl and AhCMO) had expressed in rice. But there were different expressions in the different lines, and the expressions of OsbHLHl gene in transgenic plants were significantly higher than these of non-transgenic control.(3) The agronomic traits of the transgenic lines in T2 generation were investigated, the results showed that there were significant differences between transgenic lines and control in plant height, panicle length,1000-grain weight, seed setting and theoretical yield. The results of OsbHLH1-transgenic lines were as followes:the plant height of the 7th transgenic line was shorter than that of non-transgenic control; there was no significant difference in panicle length between transgenic lines and control; the 1000-grain weight of the 6th,7th,9th and 11th transgenic line were higher than these of control; the seed setting of the 6th and 7th line was higher than that of non-transgenic control; the theoretical yield of the 6th,9th and 11th transgenic line were higher than these of control. The results of AhCMO-transgenic lines were as followes:the plant height of transgenic lines were shorter than those of non-transgenic control; there was no significant difference in panicle length between transgenic lines and control; the 1000-grain weight of the transgenic lines were higher than these of control; the seed setting of the 2nd,6th and 7th line were lower than those of non-transgenic control; the theoretical yield of the 2nd,5th,6th and 7th transgenic line were lower than those of control, but the theoretical yield of the 10th transgenic line was higher than that of control. Overall, the agronomic traits of transgenic lines were greatly influenced by foreign genes or transformation.(4) After stressed in low temperature (2℃for 6 d) and recovered growth for 6 days at germination stage, the mortality rates of T3 generation of OsbHLH1-transgenic lines were significantly lower than those of non-transgenic control. After stressed in low temperature (8-10℃for 7 d) and recovered growth for 3 days at seedling stage, the result showed that over-expression of OsbHLH1 gene could be able to enhance the cold tolerance of rice.(5) After stressed in 1.4%,1.6%,1.8% NaCl at germination stage for 20 days, the seedling rate of AhCMO-transgenic lines were significantly higher than those of non-transgenic control which indicated that AhCMO gene could improve salt tolerance in rice at seedling stage.