顺式调控变异在重金属抗性植物酸性蔗糖酶基因的胁迫响应转录调控中的作用

项目名称： 顺式调控变异在重金属抗性植物酸性蔗糖酶基因的胁迫响应转录调控中的作用

项目编号： No.21477093

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 化学工业

项目作者： 熊治廷

作者单位： 武汉大学

项目金额： 83万元

中文摘要： 酸性蔗糖酶因水解蔗糖提供能量、碳源和己糖信号是植物库器官建成的关键酶，对重金属极端污染环境中抗性植物生根、结实和抗性维持有重要作用。近期发现，重金属胁迫下抗性植物的该酶基因的转录无例外显著上调，其非编码顺式调控区发生多处突变，出现多个潜在的金属响应元件。但是未知这些顺式元件突变是否与其基因转录上调以响应重金属胁迫相关。本项目用TAIL-PCR、PCR区段缺失和定点突变、重组载体构建、报告基因融合、拟南芥异源表达、酵母单杂交及凝胶阻滞实验等方法，鉴定商周古铜矿遗址抗铜植物该基因顺式调控变异，挖掘新型金属响应元件，研究其在响应重金属胁迫的转录调控中的作用。新型金属响应元件可用于创建人工修饰启动子，培育新型工程植物用于重金属污染环境的植物修复、生态恢复和重金属废弃物生物处理。新型金属响应元件及其转录因子的鉴定还有助于深入阐明重金属胁迫下抗性植物酸性蔗糖酶基因乃至其它重金属响应基因的表达调控网络。

中文关键词： 生态毒理学；生态毒理；分子机制；生态效应；分子生物学

英文摘要： Acid invertases are key enzymes for controlling organogenesis of sink organs of plants by providing energe, carbon and hexose signals through hydrolysis of sucrose, and play an important role in rooting, fructification and tolerance maintenance in metallophytes found in uncommonly contaminated environments by heavy metals. The transcription of acid invertase genes is significantly up-regulated by heavy metal stress. It has been recently discovered that, mutation arises in cis-regulation region of acid invertase genes in metallophytes, forming sevreal potential metal response elements (MREs). However, it is not clear whether these MREs are associated with the transcriptional up-regulation of the genes. This project is to identify the cis-regulatory changes,mine new type of MREs, and study their function in the trascriptional regulation in response to heavy metal stress in native Chinese metallophytes found in ancient Cu mines that appeared since the Shang and Zhou dynasties, by means of TAIL-PCR, deletion and site-directed mutagenesis, recombinant plasmid construction, fusions with reporter gene, heterologous expression in Arabidopsis thaliana, Yeast One-hybrid and Electrophoretic Mobility Shift Assays. The novel MREs can be used to construct synthetic promoters for breeding new types of transgenic plants which will have important applications in phytoremediation, ecological restoration and biological treatment of heavy metal wastes. Also, identification of MREs and the associated transcription factors will contribute to elucidation of the regulation network of expressions of acid invertase genes and even other heavy metal responsive genes.

英文关键词： ecotoxicology;ecological toxicity;molecular mechanism;ecological effect;molecular biology