小盐芥 TsPIP1;1 与 TsTIP1;1 基因增强转基因水稻耐盐性

【目的】为更好地了解植物水通道蛋白盐胁迫下的调节作用，对小盐芥质膜内在蛋白TsPIP1;1及液泡膜内在蛋白TsTIP1;1在转基因水稻中的盐胁迫生理响应机制进行探究，旨在为水通道蛋白在耐盐作物分子改良育种中的应用提供理论支撑。【方法】以野生型 (WT) 与 T3 代转 TsPIP1;1 及 TsTIP1;1 基因水稻为材料，进行了水培试验，并设置了 0、100、200 mmol/L NaCl 处理。处理一周后，分别测定水稻的光合参数、株高、生物量、相对含水量、失水率及钾、钠含量。【结果】在盐胁迫处理下，与野生型相比，转基因水稻的生物量和含水量明显增加，渗透势和失水率显著降低。转 TsPIP1;1 及 TsTIP1;1 基因水稻根部及地上部的 Na+ 含量都显著降低，K+ 在转基因株系中的累积显著高于野生型，降低了体内 Na+/K+ 比，并且能够保持更强的净光合速率、气孔导度、蒸腾速率及水分利用效率。在 200 mmol/L NaCl 处理下，与野生型相比，TsTIP-5、TsTIP-7 及 TsPIP-19 的株高分别高出 8.2%、11.6%、4.9%；单株干重分别高出 17.9%、23.9%、16.9%；地上部 Na+/K+ 比分别降低 24.3%、24.4%、24.8%；根部 Na+/K+ 比分别降低 29.6%、27.5%、32.4%；渗透势分别显著降低了 18.3%、19.4%、30.3%；相对含水量分别增加了 5.8%、5.5%、5.4%；净光合速率分别增加了50.4%、 78.5%、56.2%。【结论】TsPIP1;1 及 TsTIP1;1 增强了转基因水稻的光合呼吸作用，通过降低植物体内 Na+/K+ 比，参与植物细胞的渗透调节，提高了细胞持水能力，促进转基因水稻的生长发育，增强了水稻的耐盐性。

Thellungiella salsuginea TsPIP1;1 and TsTIP1;1 enhanced the salt tolerance of transgenic rice

Objectives] To better understand the regulatory roles of aquaporins in plants in response to salt stress and provide a theoretical support for the application of aquaporin genes in molecular breeding of salt tolerant crop,two aquaporins of Thellungiella salsuginea,plasma membrane intrinsic protein TsPIP1;1 and tonoplast intrinsic protein TsTIP1;1,were investigated by profiling the physiological responses in the transgenic rice under salt stress.Methods] Wild type (WT) and T3 generations of the transgenic rice carrying the TsPIP1;1 and TsTIP1;1 were subjected to hydroponic solution with 0,100 and 200 mmol/L NaCl in greenhouse,respectively.After one-week's salt treatments,some important physiological parameters such as the photosynthetic rates,plant height,biomass,relative water contents,water loss rates and the contents of Na+ and K+ were determined.Results] Under 200 mmol/L NaC1 treatment,compared with the wild type,the transgenie rice exhibited higher biomass and relative water contents,and lower water loss rates and osmotic potentials,and demonstrated lower contents ofNa+ and higher contents ofK+ in roots and shoots and thus leading to lower Na+/K+ ratios.The transgenic rice maintained stronger net photosynthetic rate,stomatal conductance,transpiration rate and water use efficiency.Compared with the wild type,in 200 mmol/L NaC1 treatment,the shoot heights in the transgenic lines TsTIP-5,TsTIP-7 and TsPIP-19 were respectively increased by 8.2％,11.6％ and 4.9％,and plant dry weights were increased by 17.9％,23.9％ and 16.9％,while the Na+/K+ ratios of shoots were reduced by 24.3％,24.4％ and 24.8％,and the Na+/K+ ratios of roots were decreased by 29.6％,27.5％ and 32.4％.The osmotic potentials were significantly depressed by 18.3％,19.4％ and 30.3％,the relative water contents were increased by 5.8％,5.5％ and 5.4％,and the net photosynthetic rates were increased by 50.4％,78.8％ and 56.2％.Conclusions] The transgenic rice of carrying the TsPIP1;1 and TsTIP1;1 genes had better growth development,and enhanced the salt tolerance by increasing the photosynthesis and respiration,decreasing the Na+/K+ ratio,participating in cell osmotic adjustment and improving the water holding capacity in plant cells.