木榄多聚泛素基因BgUBQ10转化拟南芥及转基因植株耐盐功能分析  

Genetic Transformation of Bruguiera Gymnorrhiza Ploy-Ubiquitin Gene(BgUBQ10) in Arabidopsis Thaliana and Salt-Tolerant Function Analysis in the Transgenic Plants

作　　者：李谊[1] 胡文军[1] 叶波平[1] 

机构地区：[1]中国药科大学生命科学与技术学院,江苏南京210009

出　　处：《药物生物技术》2013年第2期100-105,共6页Pharmaceutical Biotechnology

基　　金：教育部"新世纪优秀人才支持计划"项目(No.NCET-05-0496)

摘　　要：泛素/26S蛋白酶体途径参与植物在盐胁迫过程中损伤蛋白或错误折叠蛋白的清除,对植物的耐盐功能发挥了重要作用。多聚泛素基因(UBQ)所表达产物为首尾相连泛素单体所组成的聚泛素蛋白,主要参与泛素/26S蛋白酶体途径中的蛋白质水解,是一个可重复利用的识别靶蛋白的信号分子。该研究前期结果显示,木榄根和叶中的BgUBQ10基因的mRNA表达水平在高盐度环境(25‰～50‰)较无盐环境(0‰)增强,而在50‰盐度环境下BgUBQ10的表达量最高;同源性比较发现,BgUBQ10与其它植物来源的UBQ在氨基酸水平上的同源性介于98%～99%之间,但进化关系较远。为了研究BgUBQ10功能,分别构建了木榄BgUBQ10基因的正义和反义表达载体,并通过根癌农杆菌介导分别转化野生型拟南芥。分别BgUBQ10过量表达转基因拟南芥、BgUBQ10反义表达转基因拟南芥与野生型拟南芥进行了耐盐性分析,BgUBQ10过量表达拟南芥植株的耐盐性明显高于野生型拟南芥植株,而BgUBQ10反义表达拟南芥植株耐盐性低于野生型拟南芥,结果提示BgUBQ10基因可能与木榄耐盐功能有关,为通过基因工程提高农作物耐盐性及培育耐盐农作物品系奠定了基础。The ubiquitin-proteasome/26 S protease pathway has played an important role in scavenging impaired or wrong-folding proteins for plants when exposed to salt stress. The translation product of poly-ubiquitin gene is poly-ubiquitin protein consisting of continuous ubiquitin member. As reusable of molecular signal in recognition of target protein, ploy-ubiquitin gene is critical during the 26S ubiquitin-proteasome induced proteolytic process. Previous results indicated that the mRNA level of BgUBQIO was increased with various salt concentration （0%o-50%o） in both roots and leaves of Bruguiera gymnorrhiza. The mRNA level of BgUBQIO in 25%o-50%~ exceeds that in 0%v and the peak appeared at 50%o. By computer analysis, BgUBQIO shares 98%-99% identity with UBQs reported in other plants respectively and there is an ignorable gap between evolutionary relationships. These experiments started from construction of an over-expressing BgUBQIO gene vector and an antisense vector which made BgUBQIO gene silent. Agrobacte- rium tumefaciens carrying over-expressing vector and antisense vector was used to build transgenic Arabidopsis thaliana. Salt-resistant experiments based on the three groups ofArabidopsis thaliana suggested that BgUBQIO gene might played a critical role in modifying salt tolerance in Bruguiera gymnorrhiza. The resuhs provide the foundation for the application of genetic engineering technique to improve salt-tolerance ability and create new varieties of salt-resistant crops.

关 键 词：木榄 盐胁迫 泛素 26S蛋白酶体途径 转基因拟南芥 蘸花法 植物基因工程 

分 类 号：R786[医药卫生—口腔医学]