毛白杨PtFT1和PtFT2基因编码区克隆与表达模式分析  

Cloning and Expression Patterns of PtFT1 and PtFT2 from Populus tomentosa

作　　者：陈仲[1] 李昊[1] 李英[1] 王佳[1] 叶梅霞[1] 郭斌[1] 季乐翔[1] 安新民[1] 

机构地区：[1]北京林业大学林木育种国家工程实验室林木花卉遗传育种教育部重点实验室国家林业局树木花卉育种与生物工程重点开放实验室,北京100083

出　　处：《中国生物工程杂志》2011年第12期63-71,共9页China Biotechnology

基　　金：国家自然科学基金(31170631);国家林业公益性项目(201004009);国家"863"计划(2011AA100201)资助项目

摘　　要：以毛白杨为材料,采用同源基因克隆法从毛白杨中分离了FT(FLOWERING LOCUS T)同源基因PtFT1和PtFT2编码区序列。测序结果表明PtFT1和PtFT2编码区长度均为525bp,可编码174个氨基酸。蛋白序列比对发现这两个基因与拟南芥、葡萄等物种中FT同源基因所编码的氨基酸同源性达到75%以上,PtFT1和PtFT2所推测的氨基酸序列包含FT类蛋白保守基序(LGRQTVYAPGWRQN)和两个关键性氨基酸残基Tyr84(Y),Gln139(Q)。系统进化分析进一步表明PtFT1和PtFT2属于FT亚家族成员。采用Real-time qRT-PCR技术检测PtFT1和PtFT2在各个组织部位中的表达模式,结果表明PtFT1和PtFT2在各个组织部位均有表达,但这两个基因的表达水平存在差异;两个基因在早期雌雄花芽(7月5日)表达量明显高于成熟雌雄花芽(翌年3月10日)表达量,进而推测在毛白杨中PtFT1和PtFT2的表达响应日照长短,长日照条件促进这两个基因的表达,它们可能在光周期调控的开花途径中促进花芽分化和开花发挥特定作用。这些研究对于阐明PtFT1和PtFT2在光周期开花调控途径中的作用机制具有重要意义,为进一步开展毛白杨开花调控基因工程研究奠定了工作基础。Two FT-like genes named PtFT1 and PtFT2 were cloned by RT-PCR from Populus tomentosa.Sequencing results indicated that the length of both PtFT1and PtFT2 is 525bp encoding 174 amino acids.Blast analysis showed that PtFT1 and PtFT2 respectively share over or more than 75% homology in amino acid sequence with Arabidopsis（Arabidopsis thaliana） FT（BAA77838.1）,grape（Vitis vinifera） FT（ABI99465.1） and other FT homologues.The deduced amino acid sequence contained one conserved motifs and two critical residues.Phylogenetic tree analysis suggested both PtFT1 and PtFT2 were classified into the FT-clade.Furthermore,the expression patterns of PtFT1 and PtFT2 in different tissues were examined using real-time quantitative RT-PCR.It showed that the constitutive and stable transcripts of PtFT1 and PtFT2 were detected in each tissue,but the expression levels between PtFT1 and PtFT2 were different.The expressions of PtFT1 and PtFT2 in male and female floral bud at early stage on July 5th were apparently higher than at late stage on March 10th in the next year.In addition,the data indicated that the expression of PtFT1 and PtFT2 in Populus tomentosa responsed to daylength,PtFT1 and PtFT2 transcripts became abundant under long days.The results suggested that PtFT1 and PtFT2 might function in photoperiod pathway about regulating flowering in Populus tomentosa.This will contribute to understanding the molecular mechanism of PtFT1 and PtFT2 in light-dependent pathways and also will benefit to regulation of flowering.

关 键 词：毛白杨 FT 表达模式 QRT-PCR 

分 类 号：Q786[生物学—分子生物学]