Study On Drought-resistance Of Transgenic Wheat With TaEBP Gene

Wheat is a kind of important food crop in the world, about70%in the worlddistribution of wheat in arid and semi-arid area. It has great significance in exploring andutilizing the drought-resistant gene resources to enhance or improve drought-resistant abilityof wheat today. Three transgenic wheat（G9-X1123, G9-X1125, G9-X1127） with TaEREB1gene and four transgenic wheat（G9-X1129, G9-X1134, G9-X1136, G9-X1139） withTaEREB2gene, receptor parent Xinchun No.9, local contrast varieties Xiaoyan22andJinmai47were used as materials. In order to comprehensively analysis and evaluate thedrought-resistant performance of transgenic plants, the materials were being investigated theircoleoptile length, radicle length and radicle numbers of wheat seedlings under PEG osmoticsolution simulated drought stress, and being further analyzed their physio-biochemical andmorphological characters （such as relative water content, relative electric conductivity,soluble protein content, proline content, MDA content, chlorophyll content, photosynthesisrate, transpiration rate） and yield or drought resistance index under different water treatmentsat field case in the middle and late growth and development stage.1The results indicated that, the coleoptile length，radicle length and radicle numbers oftest materials had been shorted or decreased in different degrees under20%concentrationsPEG-6000osmotic solution simulated drought stress, and the receptor control showed asignificant decrease while the transgenic lines G9-X1123、G9-X1125、G9-X1127、G9-X1129、G9-X1134、G9-X1136and G9-X1139showed a modest one; The descender of Xiaoyan22andtransgenic strains were not significantly different, and Jinmai47was injuried relatively smallwith stress.2Under field case at moisture critical period, with the enhancing of water stress andadvancing of the process of growth and development of wheat, the relative water content,chlorophyll content and photosynthetic rate of all materials showed a decreasing tendency, buttransgenic plants showed a slight decrease and hovered at a high level in contrast tonon-transgenic one；the leaf soluble protein and proline content of transgenic lines and thecontrasts increased with the increasing extent and duration of drought stress, as well as thetranspiration rate, but transgenic plants showed a slight accumulation and increase in contrastto non-transgenic one；The leaf relative electric conductivity and malondialdehyde content oftransgenic lines, G9-X1123, G9-X1125, G9-X1127, G9-X1129, G9-X1134, G9-X1136,G9-X1139, slightly increase in contrast to Xinchun No.9under the water stress, which indicated that the transgenic plants could effectively perform the physiological autoregulationat the aspects of cell membrane permeability of leaf and regulation ability to adapt the waterstress of soil or environment.3The results of agronomic traits and yield analysis at middle and late wheat growthstage showed that, Under three different irrigation levels, W₀, W₁and W₂, the plant height,space of spike leaf, spike length and grain number per spike of all materials had differentlevels of reduction with reducing the number of irrigation, and transgenic plants showed aslight decrease in contrast to Xinchun No.9, which could maintain a relatively stableagronomic performance under water stress. Under W₀and W₁conditions, the grain weight perplant and100-grain weight of transgenic lines were much higher than Xinchun No.9. Underthe W₀condition, the yield of G9-X1123, G9-X1125, G9-X1127, G9-X1129, G9-X1134,G9-X1136, G9-X1139respectively exceed Xinchun No.9by10.76%,29.08%,13.94%,13.95%,10.36%,10.76%,12.75%, and the drought index respectively were1.27,1.34,1.19,1.24,1.10,1.13,1.19, which belong to a strong drought-resistant level. The resultsdemonstrated that the transgenic plants show stronger resistance to drought than XinchunNo.9.