木薯MeTCP4转录因子的克隆、表达分析及植物表达载体的构建

Cloning and Expression Analysis of MeTCP4 Transcription Factor from Cassava and Construction of Plant Expression Vector

TCP转录因子家族基因参与植物生长及环境胁迫的多重调节,然而该家族基因在木薯中少有研究。木薯TCP家族基因有36个,系统进化树分析MeTCP4家族可分为8个亚组。MeTCP4基因是木薯TCP家族36个基因之一,可被miR319转录后剪切。MeTCP4基因开放性阅读框(ORF)长1 269 bp,编码422个氨基酸,预测编码蛋白质相对分子质量为45.75 kD,理论等电点为6.17。从木薯基因组中成功克隆得到MeTCP4基因全长cDNA,荧光定量RT-PCR结果显示MeTCP4基因在各组织器官都有表达,根部表达最低、茎次之、叶子中表达最高并且MeTCP4基因受干旱及低温胁迫抑制。构建高、低植物表达载体,为进一步研究该基因的功能提供依据。

The TCP transcription factors usually act as integrators of multiple growth regulatory and environmental stimuli. However, little is known about this gene family in crop cassava （Manihot esculenta）. 36 TCP genes were identified, and the Me TCP genes could be distributed into 8 distinct groups. Me TCP4 gene, which can be targeted by miR319, is one of the 36 genes in the MeTCP family. MeTCP4 contained an open reading frame （ORF） of 1 269 bp, which encoded a protein with 422 amino acids with a predicted molecular weight of 45.75 kD and PI of 6.17. The full length c DNA sequence of Me TCP4 was cloned from the cassava genome, and quantitative real time RT-PCR results showed that the expression of Me TCP4 could be found in all the tested tissues, with expression highest in leaves but less lower in stems and lowest in roots. Moreover, Me TCP4 gene was repressed by drought and low temperature stress. MiR319-resistant Me TCP4 （rMe TCP4） gene and overexpression of Me TCP4 （Me TCP4- SRDX） was cloned into vector pCAMBIA1301. These works might provide an opportunity for future research to uncover the functions of Me TCP4 in cassava.