Screening And Identification Of Drought Resistance With Transcription Factor Genes DREB 4A And W17 Transgenic Lines In Wheat

Wheat is one of the three major grain crops in China, the planting areas are mainly in northern China.Drought is one of the main abiotic stress factor in northern China,which caused by wheat yield decreased and quality decreased.According to statistics,the drought resistance made wheat yield decreased 500 million tons every year.With global warming and the shortage of water resource, drought would be a serious issue to the wheat production and food security. The development of drought resistant water saving new varieties,relieving drought and water shortage as a result of the threat to has become the important topic of wheat breeding.Transcription factors play an important role in signal transduction pathway of drought stress in crops. DREB、ERF transcription factors are closely related to abiotic stress and tolerance of crops. In this study,we used DREB4A, W17 generation transgenic lines,as test materials,in rain-fed conditions. The screening and identifying of drought resistance,the major results are as follows:1. DREB4A transgenic lines:(1) Under rain-fed condition,from the heading date to filling stage, four lines:a-10, a-18, a-26, a-33 showed higher POD activity, SOD activity and relative conductivity chlorophyll content, net photosynthesis rate, proline content, relative water content than the control JI MAI 19;the relative electric conductivity and transpiration rate in each period lower than the control JI MAI 19.Through the determination of the physiological and biochemical indexes that DREB4A transcription factor gene could significantly improve osmotic adjustment ability and the drought tolerance of transgenic wheat lines.(2) The agronomic character:plant height, spike length,grain number,number of total spike,weight per 1000 grain and plot yield were higher than the control throughout the process. The plot yield of the transgenic wheat lines a-10,a-18,a-26,a-33 were respectively increased by 17.35%,13.38%,21.28%,16.05% to the control JIMAI19.The results showed that DREB4A transcription factor gene could significantly improve the drought tolerance of transgenic wheat lines.2.W17 transgenic lines:(1) Under rain-fed condition,from the heading date to filling stage, four lines:c-14,c-31,c-42,c-53 showed higher POD activity, SOD activity and relative conductivity chlorophyll content, net photosynthesis rate, proline content, relative water content than the control JI MAI 19;the relative electric conductivity and transpiration rate in each period lower than the control JI MAI 19.Through the determination of the physiological and biochemical indexes that W17 transcription factor gene could significantly improve osmotic adjustment ability and the drought tolerance of transgenic wheat lines.(2) The agronomic character:plant height, spike length,grain number,number of total spike,weight per 1000 grain and plot yield information of the transgenic wheat lines are higher than the control JI MAI 19. The plot yield of the transgenic wheat lines c-14,c-31,c-42,c-53 increased by 18.82%,13.19%,22.84%,25.90%,which shows a better agronomical character and yield potential. The results showed that W17 transcription factor gene could significantly improve the drought tolerance of transgenic wheat lines.