茶树TCP家族的全基因组鉴定及其表达分析

Genome-Wide Identification,Classification and Expression Analysis of TCP Gene Family in Tea Plant

以拟南芥TCP蛋白序列和TCP蛋白保守结构域种子文件(Pfam:03634)检索‘舒茶早’茶树(Camellia sinensis L.)基因组数据库,对茶树TCP基因(CsTCP)进行鉴定,共得到37个基因,分别编码150~607个氨基酸。蛋白质分子量介于16.8~67.6 kD,等电点介于5.10~10.52,内含子数为0~5,其中35个CsTCP定位于细胞核,1个定位于叶绿体,1个在细胞核和叶绿体都有定位。系统发育分析显示,37个CsTCP中,21个属于PCF亚家族,11个属于CIN亚家族,5个属于CYC/TB1亚家族,表明CsTCP家族成员间出现了功能分化。保守基序分析发现,CsTCP蛋白序列中至少存在20个保守基序,同源关系较近的CsTCP成员常具有相似的保守基序构成。亚细胞定位结果显示,CsTCP32定位于细胞核,CsTCP24在细胞核和细胞质都有定位,表明CsTCP蛋白具有转录因子的核定位特征。启动子元件分析发现,CsTCP基因启动子区富含干旱、盐、低温和病原菌侵染胁迫响应元件。基于转录组数据以及半定量和定量PCR分析结果显示,CsTCP基因家族成员在茶树不同组织和胁迫处理后存在差异表达。其中,CsTCP14主要在茎和花中表达,CsTCP32主要在芽和叶中表达;CsTCP19、CsTCP20、CsTCP12和CsTCP32分别在高盐、低温和MeJA处理后上调表达,CsTCP18和CsTCP30在低温和MeJA处理后下调表达。

The TCP genes of tea plant(CsTCPs)were identified from the‘Shuchazao’(Camellia sinensis L.)genomic database based on the TCP protein sequences of Arabidopsis thaliana and the conserved domain sequence of TCP proteins(Pfam:03634).In total,37 CsTCP members were identified in the tea plant genome,with the amino acid size,molecular weight,isoelectric point,and the gene intron numbers varying from 150-607 aa,16.8-67.6 kD,5.10-10.52,and 0-5,respectively.Subcellular location analysis showed that 35 CsTCP members were localized in cell nucleus,1 CsTCP member was localized in chloroplast,and 1 CsTCP member was localized in both cell nucleus and chloroplast.There are 21 PCF,11 CIN and 5 CYC/TB1 clusters in tea plant genome according to the phylogenetic analysis,suggesting that functional differentiation occurred among the CsTCP members.Conserved motifs analysis showed that there were at least 20 motifs in CsTCP members,and similar conserved motifs were identified in CsTCP members with a closer phylogenetic relationship.Subcellular location assay demonstrated that CsTCP32 localized in nucleus,but CsTCP24 had both nuclear and cytoplasmic locations.The result suggested that the identified CsTCPs were transcription factors with nuclear localization.Drought stress,salt stress,cold stress and pathogen infection related cis elements were abundant in the promoter region of the CsTCP genes.Based on the transcriptomic data,semi-qPCR and qPCR analysis,CsTCP gene members displayed differential expression patterns in different organs of tea plants and under various stresses treatment.Thereinto CsTCP14 was mainly expressed in stems and florets,CsTCP32 was mainly expressed in buds and leaves of tea plants,CsTCP19,CsTCP20,CsTCP12 and CsTCP32 was respectively up-regulated after salt,cold and MeJA treatment,CsTCP18 and CsTCP30 was respectively down-regulated after cold and MeJA treatment.