茶树细胞周期蛋白基因的克隆与表达

以茶树萌动芽为材料,采用SMART-RACE PCR技术从茶树萌动芽中获得了茶树细胞周期蛋白基因的全长cDNA序列(命名为CsCYC1),并用实时定量PCR方法(qRT- PCR)研究了该基因在茶树越冬芽休眠到萌发后不同阶段的表达模式.结果显示:(1)该基因全长1956 bp,包含1320 bp的开放阅读框(ORF),编码439个氨基酸残基.(2) CsCYC1预测分子量为49.35 kD,具有细胞周期蛋白家族典型的保守cyclin-box结构域和三维结构.(3)系统进化分析结果表明,CsCYC1的氨基酸序列与葡萄、蓖麻、毛果杨、琴叶鼠耳芥、拟南芥等的相似性分别为77％、74％、72％、68％和67％.(4)实时荧光定量PCR分析显示,CsCYC1基因在茶树越冬芽休眠期的表达量远低于恢复生长期,在萌发期表达量最高,说明该基因与茶树越冬芽休眠的解除关系密切.

Cloning and Expression Analysis of Cyclin Gene(CsCYC1) of Tea Plant

The full length cDNA of cyclin gene(CsCYC1) was cloned from the sprouting buds of tea plant(Camellia sinensis) by SMART-RACE-PCR based on the partial sequences in sprouting bud SSH-cDNA library.The sequence and structure characteristics of its encoded protein were analyzed,and its expression patterns during the time of bud dormancy and bud break were evaluated by quantitative real-time PCR(qRT-PCR).The full length cDNA is 1956 bp(GenBank Accession No.JF795471),which includes 1 320 bp ORF and encodes 439 amino acid residues with a putative molecular mass of 49.35 kD.CsCYC1 has a typical conserved cyclin-box domain near the C-terminus and 3D structure of cyclin family.Phylogenetic analysis showed that CsCYC1 had 77%,74%,72%,68% and 67% similarity with cyclin of Vitis vinifera,Ricinus communis,Populus tomentosa,Arabidopsis lyrata and Arabidopsis thaliana,respectively.The results of quantitative real-time PCR showed that the expression level of CsCYC1 at dormant stages was lower than that at growth stages,and the highest expression level emerged at sprouting stage.It indicated that CsCYC1 had very close relationship with tea plant budbreak in spring.