Analysis Of Salt Tolerance And Drought Resistance Of Wheat Overexpressing ZmTDP1 Gene

China is a traditional large agricultural country,and wheat is one of the earliest crops planted in China and one of the main food crops in China.Salt and drought are widespread and have negative impact on the growth and development of wheats.It is an effective way to increase the resistance to salt and drought in wheat by digging genes related to salt and drought resistance and cultivating new varieties for salt and drought resistance through advanced molecular genetic engineering.TDP1 is a DNA repair system enzyme involved in removing DNA damage caused by topoisomerase I inhibitors.In previous research,our laboratory has transformed the ZmTDP1 gene from corn through Agrobacterium-mediated transformation to obtain transgenic ZmTDP1 wheat.In this study,we used transgenic ZmTDP1 wheat lines Xd and Nd as materials,to test drought and salt stress resistance.A series of phenotype characterization,physiological and biochemical measurement were made.The main results are as follows:?1?Identification of transgenic ZmTDP1 wheatThe T₃ generation of ZmTDP1 gene-transformed wheat obtained using Agrobacterium-mediated transformation and the control Fielder were sampled at the seedling stage.DNA was extracted.A total of 330 plants were identified for the ZmTDP1 gene transgenic wheat,of which 264 were positive.?2?Identification of drought resistance of ZmTDP1 transgenic wheatUnder the same PEG 6000 simulated drought stress conditions,the seed germination vigor and germination rate,root length and seedling length at seedling stage,fresh weight and dry weight per plant of transgenic ZmTDP1 wheat at germination stage were better than the control;compared with the control,the transgenic ZmTDP1 wheat the SOD activity of strains Xd and Nd increased by 15.1%and 14.3%,CAT activity increased by 12.6%and 22.1%,POD activity increased by 11%and 9.6%,and MDA content decreased by 13%and 9.4%,the chlorophyll content increased by 11.6%and 7.2%,the proline content increased by 51.7%and40.5%,and the soluble protein content increased by 11.9%and 9.1%,respectively.Meanwhile,ZmTDP1 gene was overexpressed in transgenic wheat.Based on the above results,ZmTDP1transgenic wheat showed stronger drought resistance.?3?Identification of salt tolerance of ZmTDP1 transgenic wheatUnder the same NaCl simulated salt stress,the seed germination vigor and germination rate,the average root length and seedling length at the seedling stage,and the fresh weight and dry weight per plant of the transgenic ZmTDP1 wheat at the germination stage were better than the control;compared with the control,the transgenic ZmTDP1 wheat SOD activity of strains Xd and Nd increased by 16.5%and 19.5%,CAT activity increased by 12%and 23%,POD activity increased by 19.1%and 16.7%,MDA content were reduced by 23.3%and25.8%,the chlorophyll content were increased 7.1%and 8.4%,the soluble protein content increased by 10.6%,and the soluble sugar content increased by 43.3%and 49.7%,respectively.Meanwhile,ZmTDP1 gene was overexpressed in transgenic wheat.Based on the above results,transgenic wheat with ZmTDP1 gene showed stronger salt tolerance.