蓝细菌蔗糖合成关键基因spsA转录调控研究

项目名称： 蓝细菌蔗糖合成关键基因spsA转录调控研究

项目编号： No.31301018

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 生物科学

项目作者： 谈晓明

作者单位： 中国科学院青岛生物能源与过程研究所

项目金额： 25万元

中文摘要： 蔗糖是蓝细菌响应盐胁迫而合成并积累的一种渗透调节物质，在蓝细菌响应和适应盐胁迫的过程中发挥了重要的作用。spsA基因编码单细胞蓝细菌蔗糖合成途径关键酶蔗糖-磷酸合成酶，该基因受到盐胁迫诱导转录，但是其转录调控的具体分子机制仍不明确。本项目将在前期工作已鉴定了spsA启动子区域一个顺式作用元件的基础上，以蓝细菌全基因组随机突变和酵母单杂交等技术，筛选和鉴定与该顺式作用元件相互作用并控制spsA基因转录的转录因子，再通过凝胶阻滞实验体外研究鉴定得到的转录因子与顺式作用元件的相互作用机制，以及通过实时定量PCR和离子色谱分析等技术，动态分析盐胁迫条件下转录因子和spsA的转录以及蔗糖合成情况，解析spsA转录调控的具体机制，探索盐胁迫诱导蔗糖合成的信号通路和具体分子机理，这对于进一步解析蓝细菌盐胁迫响应和适应机制以及阐明光合生物高盐适应的普遍规律具有重要的意义，也有助于建立新一代糖资源平台。

中文关键词： 蓝细菌；spsA；转录调控；蔗糖；盐胁迫

英文摘要： Sucrose, which is a kind of compatible solutes synthesized and accumulated under salt stress, plays an important role on responding and acclimation to salt stress in cyanobacteria. The spsA gene, encoding sucrose-phosphate synthase which catalyzes the key step of sucrose biosynthesis, is salt-induced in unicellular cyanobacteria. Recently, we have identified a key cis-acting element from the upstream region of the spsA gene which controls the spsA transcription under salt stress. However, the molecular mechanisms of spsA transcriptional regulation is still unclear. In this study, the transcription factors which could interact with this cis-acting element and also control the transcription of spsA will be firstly screened and identified from the cyanobacterial genome. Then the molecular mechanism on interaction between this cis-acting element and the identified trancription factors will be elucidated by electrophoretic mobility shift assay experiments. And the dynamic transcription of spsA and the identified transcription factors as well as the sucrose content in cyanobacteria under the normal culture condition and salt stress will be anaylzed by Real-Time PCR and ion chromatography analysis. By performing these researches, detailed mechanisms on transcriptional regulation of spsA will be interpreted. And this st

英文关键词： cyanobacteria；spsA；transcriptional regulation；sucrose；salt stress