蔗糖转运蛋白基因CsSWEET1调控黄瓜亚适温下光合同化物韧皮部装载的机制研究

项目名称： 蔗糖转运蛋白基因CsSWEET1调控黄瓜亚适温下光合同化物韧皮部装载的机制研究

项目编号： No.31301792

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 农业科学

项目作者： 胡丽萍

作者单位： 北京市农林科学院

项目金额： 24万元

中文摘要： 黄瓜（Cucumis sativus L.）是典型的喜温蔬菜，在设施栽培中常遭遇亚适温环境胁迫，是限制黄瓜高产高效栽培的关键因子之一。已有研究表明，增强亚适温下叶片同化物向韧皮部的装载能力，可提高同化物从叶片向"库"器官转运的能力，从而提升黄瓜对亚适温的适应能力。预备实验结果表明，最新报道的新型蔗糖转运蛋白基因CsSWEET1在不同亚适温耐性黄瓜品种间存在较大的表达差异。本项目在进一步验证CsSWEET1基因蔗糖双向转运功能的基础上，综合运用荧光定量PCR、GUS和免疫组织化学染色、黄瓜原生质体瞬时表达和胶体金免疫电镜定位等技术开展该基因的时空表达、组织和亚细胞定位分析，并研究该基因在不同亚适温耐性品种间基因序列和结构上的差异，最终明确该基因是否参与了黄瓜亚适温下同化物韧皮部装载及其调控机制，为设施条件下黄瓜对亚适温的适应机制研究提供新线索，为培育耐亚适温设施黄瓜品种提供理论基础。

中文关键词： 黄瓜；糖转运蛋白；SWEET；叶片；内质网

英文摘要： Cucumber (Cucumis sativus L), a typical thermophilic vegetable, often suffer from suboptimal temperature which has become one of the key limiting factors of cucumber cultivation in protected horticulture. It has been hypothesized that enhancing the capacity of photoassimilates phloem loading may improve the transporting capacity of photoassimilates from source leaves to sink organs, so as to enhance the ability of cucumber adapting to suboptimal temperature. Our preliminary experimental results showed that a novel sucrose transporter CsSWEET1 displayed a sharp difference in expression levels between suboptimal temperature tolerant and sensitive cultivars. In this study, the function of CsSWEET1 on the bidirectional transport of sucrose will be further verified. Furthermore, using a combination of real-time PCR, GUS and immunochemical staining, cucumber protoplast transient expression and immunogold labeling, the spatiotemporal expression, tissue and subcellular localization of CsSWEET1 will be studied. In addition, the differences in sequence and structure of CsSWEET1 between suboptimal temperature tolerant and sensitive cultivars will also be analyzed. These results will determine whether CsSWEET1 is involved in photoassimilates phloem loading in source leaves of cucumber under suboptimal temperature, as well a

英文关键词： Cucumber；Sugar transporter；SWEET；Leaf；Endoplasmic reticulum