Abstract: TCP gene family is a class of transcription factors unique to plants and closely related to different stages of plant growth and development. There are few reports on the TCP gene family in melon.In this study，the members of the TCP gene family in melon were identified through bioinformatics methods，and their physicochemical properties，subcellular localization，phylogenetic evolution，chromosomal location，gene structure，conserved motifs，cis‑elements，miRNAs and gene expression patterns were analyzed.The results revealed that a total of 29 members were identified within the TCP gene family.All these members contained the TCP domain and were unevenly distributed across nine chromosomes.The amino acid numbers of melon TCP transcription factor family proteins ranged from 61 to 600 aa，the molecular weights ranged from 7 115.16 to 65 469.20 u，and the theoretical isoelectric points ranged from 5.62 to 10.06.Subcellular localization prediction analysis revealed that 28 TCP proteins were localized within the nucleus.According to the phylogenetic analysis，the family members could be divided into two subfamilies，Class Ⅰ and Class Ⅱ ，and further subdivided into three subgroups：PCF，CYC/TB1 and CIN.The gene structures of CmTCPs were relatively simple，all members containing 1 or 2 exons，and only a few genes contained introns.All the 29 genes contained motif 1，and the Motifs contained by different subgroups were different.The cis‑element prediction analysis showed that the promoter sequences of the melon TCP gene family were mainly composed of light response，hormone response，growth and development‑related elements.The miRNA prediction analysis obtained 25 miRNAs interacting with 13 CmTCP genes.The analysis of RNA‑Seq data of melon genome database showed that 26 CmTCP genes had both distinct tissue‑specific expression and specific expression in certain tissue parts in melon tissues.The results of qRT‑PCR indicated that the relative expression levels of CmTCP‑CYC/TB1 gene family members in different tissues of melon were significantly different.

Key words: Melon, TCP gene family, Bioinformatics analysis, Genome?wide identification, Gene expression analysis

摘要： TCP基因家族是植物体内特有的、与植物生长发育的不同阶段密切相关的一类转录因子，在甜瓜中的研究鲜见报道。利用生物信息学方法对甜瓜TCP基因家族成员进行鉴定，并对其理化性质、亚细胞定位、系统进化、染色体定位、基因结构、保守基序、顺式元件、miRNA及基因表达模式进行分析。结果表明，鉴定出29个含有TCP结构域的TCP基因家族成员，不均等地分布在9条染色体上。甜瓜TCP转录因子家族蛋白的氨基酸数在61~600 aa，分子质量在7 115.16~65 469.20 u，理论等电点在5.62~10.06。亚细胞定位预测分析表明，28个TCP蛋白定位在细胞核。根据系统发育分析可将家族成员划分为Class Ⅰ和Class Ⅱ 2个亚家族，进一步细分为PCF、CYC/TB1、CIN 3个亚组。CmTCP基因结构都比较简单，均含有1或2个外显子，极少数基因含有内含子，29个基因都含有Motif 1，不同亚组成员含有的Motif存在差异。顺式元件预测分析显示，甜瓜TCP基因家族启动子序列以光响应、激素响应、生长发育调控等相关元件为主。miRNA预测分析得出25个miRNA与13个CmTCP基因相互作用。甜瓜基因组数据库RNASeq分析显示，26个CmTCP基因在甜瓜组织中既有明确的组织分工表达，又有特定的组织部位表达；qRT-PCR结果表明，CmTCP-CYC/TB1基因成员在甜瓜不同组织中的相对表达量差异显著。

关键词: 甜瓜, TCP基因家族, 生物信息学分析, 全基因组鉴定, 表达分析