黄瓜CsNADP-ME1基因对干旱胁迫的响应机理研究

黄瓜叶片大、根系分布浅、蒸腾作用大，干旱胁迫是限制黄瓜产量和品质的重要因素。苹果酸是参与植物干旱胁迫的重要有机酸，NADP-ME是苹果酸代谢的重要酶，已有研究证明其参与植物干旱胁迫，但对于该基因在黄瓜中参与干旱响应逆境胁迫的调控机制尚未明确。申请人前期从黄瓜中分离到在叶片中高表达的CsNADP-ME1基因，并证明其受干旱胁迫和ABA的诱导；干旱条件下，CsNADP-ME1基因RNA-干扰黄瓜株系的失水率较野生型显著升高，转基因株系的抗旱性降低。在此基础上，本项目拟进一步对CsNADP-ME1进行组织化学及亚细胞定位、黄瓜同源表达系统中功能分析、启动子干旱响应区域分析、上游关键调控因子筛选与功能验证等，研究CsNADP-ME1基因及其上游关键调控基因在干旱胁迫中的功能，以明确其参与抗干旱逆境胁迫的分子生理机制，为进一步研究黄瓜抗干旱逆境研究提供理论依据。

Cucumber possesses large leaves and shallow roots, which makes high transpiration. Drought stress is an important factor limiting cucumber yield and quality. Malic acid is an important organic acid involved in plant drought stress, and NADP-ME is an important enzyme of malic acid metabolism. It has been proved that NADP-ME is involved in plant drought stress, but the regulation mechanism has not yet been clear. The CsNADP-ME1 gene, highly expressed in cucumber leaves, was isolated previously, which was induced by drought stress and ABA. Under drought conditions, higher rate of water loss was detected in CsNADP-ME1 RNA-interfering lines relative to wild plants, suggesting reduced drought resistance of RNA-interfering lines. On this basis, we intends to research the function of CsNADP-ME1 gene and upstream key regulatory factors through histochemistry and subcellular localization, promoter analysis, upstream key regulatory factors screening, and functional analysis in cucumber homologous expression systems. The project aims to clarify the molecular and physiological mechanisms of CsNADP-ME1 involved in drought stress resistance, and provide a theoretical basis for further research on cucumber drought resistance.