厚藤cDNA文库的构建和重金属镉耐受相关基因的筛选

Construction of a c DNA library of Ipomoea pes-caprae L. and screening for cadmium tolerant genes

厚藤(Ipomoea pes-caprae(L.)Sweet)是一种具有重要生态、观赏及药用价值的沙滩植物,对重金属镉(Cd)具有一定的富集能力,可作为Cd污染滨海地区的修复植物进行引种栽植和利用。本研究通过Gateway技术构建厚藤的cDNA文库,将该文库质粒转化酵母对Cd敏感的突变株ycf1Δ,采用全长cDNA过表达基因捕获系统(FOX)筛选厚藤重金属Cd胁迫耐受相关基因,并采用酵母互补实验进行基因的功能验证。本研究获得了2个能够恢复ycf1Δ对Cd敏感表型的重组质粒,经测序分析,该重组质粒包含的cDNA全长序列分别对应厚藤植物螯合肽合成酶基因(phytochelatin synthase)和金属硫蛋白基因(metallothionein),分别将其命名为Ip PCS和Ip MT,通过功能分析,初步认定该基因为编码Cd耐受和解毒相关蛋白的候选基因。

Ipomoea pes-caprae （L.） ecological, ornamental, and medicinal and can be used in phytoremediation. Sweet, as a coastal beach halophyte with great value, has the capacity to enrich heavy metal cadmium We constructed a cDNA library for expression in yeast with tissues of Ipomoea pes-caprae by gateway technology, and then introduced the library plasmids into cadmium-sensitive yeast mutant strain, ycflA, and screened the library through the FOX gene hunting system based on functional screening in yeast. We obtained two full- length cDNAs of Ipomoea pes-caprae, which could enhance the Cd tolerance of ycflA. Sequence analyses indicated that these two cDNAs encoded phytochelatin synthase （IpPCS） and metallothionein （IpMT）. This research molecular mechanism of plants responding ays a good foundation for further clarifying the to cadmium, and provides a reference cDNA library for functional screening to clone other stress-related genes in Ipomoea pes-caprae