香蕉trihelix转录因子MaGTL1a的分离及特性  

Identification and characterization of a trihelix transcription factor MaGTL1a from banana

作　　者：梁淑敏[1] 罗冬兰[1] 程玉瑾[1] 俞乐安 杨亚杰[1] 陈建业[1] 陆旺金[1] 邝健飞[1] 

机构地区：[1]华南农业大学园艺学院.南方园艺产品保鲜教育部工程研究中心.广东省果蔬保鲜重点实验室,广州510642

出　　处：《果树学报》2017年第8期935-945,共11页Journal of Fruit Science

基　　金：广州市珠江科技新星专项(201506010080);国家香蕉现代农业产业技术体系(CARS-32-09);华南农业大学校级创新训练项目(201510564122)

摘　　要：【目的】研究香蕉MaGTL1a转录因子的特性及其基因表达规律,探讨MaGTL1a转录因子在香蕉果实成熟过程中的作用。【方法】以香蕉果肉c DNA为模板,采用RT-PCR获得MaGTL1a序列;利用烟草瞬时表达法和酵母系统分析MaGTL1a亚细胞定位和转录调控活性;通过实时荧光定量PCR分析MaGTL1a在香蕉果实成熟过程中的表达;运用烟草BY2悬浮细胞瞬时表达法研究MaGTL1a启动子活性。【结果】MaGTL1a c DNA序列含有1个2 283 bp的开放阅读框,编码761个氨基酸,属于trihelix转录因子的GT-2亚家族;亚细胞定位和转录活性分析显示,MaGTL1a定位于细胞核,并在酵母和植物体内具有转录激活活性;实时荧光定量PCR和启动子活性试验表明,MaGTL1a转录水平和启动子活性均受乙烯诱导,并且MaGTL1a转录水平随着香蕉果实的成熟进程而明显增强。【结论】MaGTL1a是一个受乙烯诱导和核定位的转录激活子,可能参与了香蕉果实成熟的调控。【Objective】The trihelix transcription factors, also known as GT factors, are plant-specific transcription factors with conserved trihelix DNA-binding domains that bind specifically to the GT elements in promoters of light regulated genes. The trihelix transcription factors can be further divided into five clades, namely GT-1, GT-2, SH4, GTγ and SIP1, on the basis of their sequence structure. To date, the trihelix transcription factors have been identified and characterized in various plant species, such as pea,Arabidopsis, rice, maize, tomato, and chrysanthemum. A large number of studies indicated that trihelix transcription factors played an essential role in the regulation light-responsive genes, and different developmental processes of growth and development of flowers, embryos, seeds, stomata and trichomes, as well as the adaptation to environmental stimuli like salt and pathogen stresses. However, little information was available on the involvement of the trihelix transcription factors in the ripening of fleshy fruits, especially in economical fruit crops such as banana. Therefore, the aims of this study were to isolate a trihelix tran-scription factor from banana fruit（MaGTL1a）, and investigate its subcellular localization and transcription-al activation activity. Moreover, the gene expression during banana fruit ripening and the promoter activity of MaGTL1 a were also analyzed, in an effort to elucidate the possible roles of MaGTL1 a in the ripening of banana fruit.【Methods】Total RNA was extracted from banana pulp using the hot borate method and the first strand c DNA was synthesized. RT-PCR was performed to isolate the full-length c DNA of MaGTL1 a.Bioinformatics analysis was conducted to analyze the sequence characteristics of MaGTL1 a. Phylogenetic tree was constructed using the MEGA 6.0 software to investigate the evolutional relationship between MaGTL1 a and other trihelix transcription factors from other plant species. Agrobacterium-mediated transient expression in Ben＇s tobacco leaves

关 键 词：香蕉果实 成熟 转录因子 Trihelix 表达 

分 类 号：S668.1[农业科学—果树学]