Drought Resistance Research Of Transgenic Brassica Napus L. With DR1172 Gene Driven By Different Promoters

Drought is one of the most influential abiotic stress for plant during its process of growth and development, which has badly affected the development of the global agriculture. At present, the research regards to the mechanism of drought resistance and to cultivate some novel plants with drought resistance by biotechnology has become a hot pot. Brassica napus L., belonging to Cruciferae Brassica, is one of the main sources of vegetable protein and vegetable oil. In China, the output of rapeseed decreased more than 20% every year result from drought stress. Recently, several progress has been achieved by transfering some exogenous gene into Brassica napus L. using genetic engineering, while not only did the resistance of drought increase, but also didn't affect the quality of rape has been get more attention.In this study, to analysis the ability of two different promoters driven DR1172 in transgenic Brassica napus L.in improving drought resistance and its physiological and biochemical differences, the plant expression vectors of DR1172 gene driven by the promoter of CaMV35 S and AtPUB19 respectively were constructed, and transferred it into Brassica napus L. using Agrobacterium mediated method, the final goal of this study is obtain new Brassica napus L. with good comprehensive characters.The results are as follows:(1)The plant expression vector pCambia-AtPUB19::DR1172 and PBI121-CaMV35S::DR1172 were constructed respectively, and then transformed it into EHA105 competent cells successfully.(2) The software has been used to analysis the structure, the results indicated that the promoter the AtPUB19 contains cis-acting elements such as drought, dehydration responsive element, start conservative elements of the promoter and enhancer, start the core conserved sequences, and prediction of the two transcription start site.(3)To get the transgenic Brassica napus L.containing pCambiaAtPUB19::DR1172 and PBI121-CaMV35S::DR1172 respectively, the method ofagrobacterium mediated was used and obtained 78 transformant containing AtPUB19::DR1172 and 46 containing PBI121-CaMV35S::DR1172 by PCR.(4)The processing method of drought using PEG6000 simulation experiment, the T1 generation seed(not turn, turn At PUB19::DR1172, CaMV35S::DR1172) of different concentrations of PEG stress processing experiment and 20% PEG concentration different time of stress under the processing experiment. The results indicated that under different drought stress, the function drought resistance gene DR1172 can be effectively drived by AtPUB19 and CaMV35 S, while when the they faced with highly drought stress, turn At PUB19 promoter can be more efficient in driving DR1172 and the antioxidant enzyme activity of transgenic Brassica napus L. containing At PUB19 is signifacantily higher than CaMV35 S. when they faced drought stress with different time,the antioxidant enzyme activity of transgenic Brassica napus L.containing CaMV35S::DR1172 and AtPUB19::DR1172 were increased and the non transgenic group showed a trend of increased firstly and then decreased. At the same time, DR1172 gene drived by CaMV35 S promoter and At PUB19 promoter can alleviate tissue damage from MDA. the decrease of chlorophyll content, relative water content and inceeased of relative electric conductivity was found in transgenic plant containing At PUB19 promoter, what's more, the content of proline and soluble sugar increased, which plays a important role in reducing the damage from drought.(5) The real-time fluorescent quantitative PCR technology also used, the data showed that with the increase of drought stress time, CaMV35 S promoter express at a lower level, however, DR1172 gene deived by At PUB19 express a higher level.(6) The leaf morphological was observed under 20% PEG treatment in different periods, At PUB19 promoter can improve the ability of drought driven gene of drought level with highly drought stress, which is more efficient than CaMV35 S. At the same time, the express of gene DR1172 drived by CaMV35 S don't have the time and tissue specificity, but the express of gene DR1172 can be induced by At PUB19 can be specificity n according to developmental stages, growth environment, time, location andquantitative, and then reduce adverse effects on the shape and quality of transgenic Brassica napus L..