谷子TCP转录因子家族成员鉴定与生物信息学分析

Identification and bioinformatics analysis of TCP transcription factor family member in Setaria italic L.(foxtail millet)

【目的】鉴定谷子TCP转录因子家族成员,并进行生物信息学及组织表达特性分析,为探究谷子TCP转录因子在植物生长发育、激素信号途径和生物胁迫中的生物学功能提供理论依据。【方法】通过HMMER构建隐马尔可夫模型,在谷子蛋白数据库中搜索含有TCP特征性结构域的TCP蛋白,对其理化性质、保守基序和系统发育进化进行分析,并对其基因结构、启动子顺式作用元件及组织表达特性进行分析。【结果】从谷子蛋白数据库中共鉴定出23个TCP转录因子(编号SiTCP1~SiTCP23),氨基酸数量为95~451个,分子量为9743.9~46502.6 Da,理论等电点(pI)为4.2682~11.8710,其编码基因在9条染色体上呈不均匀方式分布。23个谷子TCP蛋白被分为3个亚族,其中GroupⅠ和GroupⅢ中各有10个TCP蛋白,GroupⅡ有3个TCP蛋白。谷子TCP蛋白保守基序的组成存在一定差异,但亲缘关系较近的蛋白具有相同的保守基序,部分谷子TCP蛋白含有特殊的基序;除SiTCP5、SiTCP20、SiTCP18和SiTCP22外,其余TCP蛋白均含有保守Motif 1和Motif 2。除SiTCP1、SiTCP6和SiTCP14基因仅包含1个内含子外,其余TCP基因均无内含子,且亲缘关系较近的基因具有相似结构。谷子TCP基因的启动子含有光应答元件、激素响应元件、应激响应元件及分生组织表达应答元件等。谷子TCP基因在不同组织中具有特异性,且大部分TCP基因在穗状花序和茎中高效表达。【结论】同亚族的谷子TCP转录因子家族成员具有相似的保守基序和基因结构,推测其在激素信号途径、应答非生物胁迫(干旱和低温)及生长发育中发挥重要作用。

【Objective】Gene family members of TCP transcription factorin foxtail millet were identified,their bioinformatics and expression in different tissues were analyzed.This would provide a theoretical basis for studying the function of foxtail millet TCP transcription factor in development,hormone signaling pathway and biotic stress.【Method】By constructing a hidden Markov model by HMMER,the TCP proteins contained TCP domain were scanned in the foxtail millet protein database,its physicochemical property,conserved motifs and phylogenetic evolution were analyzed,and the gene structure,promoter region cis-acting elements and tissue expression specific of encoding gene were analyzed.【Result】Twenty-three TCP transcription factors(number:SiTCP1-SiTCP23)were identified from foxtail millet protein database,the number of amino acids was 95-451,and the molecular weight was 9743.9-46502.6 Da.The theoretical isoelectric point(pI)was 4.2682-11.8710.The encoding genes were distributed unevenly on nine chromosomes.The 23 foxtail millet TCP transcription factors were divided into three subgroups,GroupⅠand GroupⅢcontained each 10 TCP proteins,and GroupⅡcontained 3 proteins.There were some differences in the composition of the conserved motifs infoxtail millet TCP proteins,but proteins with close genetic relationship had the same conserved motifs,some of which contained special mo-tifs.Except SiTCP5,SiTCP20,SiTCP18,and SiTCP22,the remaining TCP proteins contained conservative Motif 1 and Motif 2.With the exception of SiTCP1,SiTCP6 and SiTCP14,which contain only one intron,all the other TCP genes did not contain introns,and the closely related genes had similar structures.The foxtail millet TCP gene promoter region contained light response elements,hormone response elements,stress response elements,meristem expression response elements.The TCP genes of foxtail millet was specific in different tissues and most TCP genes were highly expressed in spica and stem.【Conclusion】The members of foxtail millet TCP transcription factor in the same subgroup have similar conserved motifs and gene structures,which are speculated to play important roles in hormone signaling pathways,response to abiotic stress(drought and low temperature),and growth and development.