CO2加富调控黄瓜质膜水孔蛋白介导的CO2和H2O跨膜运输机理研究

CO2 deficit and drought stress frequently occur in cucumber protected cultivation. Our previous studies showed that CO2 enrichment can alleviate the impairment of cucumber seedlings from drought stresses. The plasma membrane intrinsic proteins (PIPs) control water flux into and out of veins and stomatal guard cells and also increase membrane permeability to CO2 in mesophyll and stomatal guard cells. At present, it is not clear about the mechanism of aquaporins mediating transmembrane transport of CO2 and H2O in drought-suffered cucumber plants under elevated CO2 condition. We have already screened three cucumber plasma membrane intrinsic proteins (CsPIPs). By adopting the methods from biophysics, plant physiology, and molecular biology, the following research will be performed: (1) response of water transmembrane transport process to drought stress and CO2 enrichment mediated by CsPIPs; (2) isolation, cloning and localization of CsPIPs gene; (3) regulation of CsPIPs gene expression, abundance and activity of protein of cucumber seedlings under CO2 enrichment and drought stress, (4) mechanism that ABA and H2O2 involved in the transport of CO2 and H2O mediated by CsPIPs. The purpose of this study is to illuminate the physiological mechanism that CO2 enrichment alleviating the adverse effects of drought stress on cucumber at the molecular, cellular, organic and whole plant levels, which may provide theory basis for cucumber cultivation with high quality and efficiency as well as germplasm improvement of cucumber with drought-tolerant traits.

黄瓜设施栽培中经常会出现CO2亏缺和干旱胁迫现象，我们前期研究表明CO2加富能够缓解黄瓜幼苗受到的干旱胁迫。质膜水孔蛋白不但控制进出叶脉和气孔保卫细胞的水通量，而且可增加气孔保卫细胞和叶肉细胞对CO2的膜透性。目前关于CO2加富下水孔蛋白介导受旱黄瓜叶片CO2和H2O的跨膜运输调控机制鲜见报道。本项目在已筛选出3个黄瓜质膜水孔蛋白（CsPIPs）的基础上，结合生物物理学、植物生理学及分子生物学手段，拟从CsPIPs介导的水分跨膜运输过程对CO2加富和干旱胁迫的响应，CsPIPs基因的分离、克隆及定位，CO2加富对受旱黄瓜幼苗CsPIPs基因的表达及蛋白丰度与活性的调控，以及ABA和H2O2参与CO2加富调控CsPIPs介导的CO2和H2O传输机理四个方面开展研究，以期从分子、细胞、器官及整株水平阐明CO2加富缓解黄瓜干旱胁迫的生理机制，为设施黄瓜优质高效栽培和耐旱品种遗传改良提供理论依据。

本项目筛选出3个黄瓜质膜水孔蛋白（PIP1-1，PIP2-4和PIP2-5），结合生物物理学、植物生理学及分子生物学手段，从CsPIPs介导的水分跨膜运输过程对CO2加富和干旱胁迫的响应，CsPIPs基因的分离、克隆及定位，CO2加富对受旱黄瓜幼苗CsPIPs基因的表达及蛋白丰度与活性的调控，以及ABA和H2O2参与CO2加富调控CsPIPs介导的CO2和H2O传输机理四个方面开展研究，从分子、细胞、器官及整株水平阐明了CO2加富缓解黄瓜干旱胁迫的生理机制，为设施黄瓜优质高效栽培和耐旱品种遗传改良提供理论依据。