茶树品种‘安吉白茶’CsDREB-A4b基因的克隆及其对非生物胁迫的响应

Cloning of CsDREB-A4b gene from cultivar ‘Anjibaicha'of Camellia sinensis and its response to abiotic stress

采用RT-PCR方法从茶树〔Camellia sinensis(Linn.)O.Ktze.〕品种‘安吉白茶’(‘Anjibaicha’)叶片的c DNA中克隆得到1个编码DREB转录因子的基因,命名为CsDREB-A4b。序列分析结果显示,CsDREB-A4b基因包含长度为873 bp的开放阅读框,编码290个氨基酸,具有保守的AP2结构域。与拟南芥〔Arabidopsis thaliana(Linn.)Heynh.〕AP2/ERF家族转录因子进行同源进化分析,CsDREB-A4b转录因子属于DREB亚族中的A4组。多重比对结果显示:CsDREB-A4b转录因子与蓖麻(Ricinus communis Linn.)等植物的DREB类转录因子保守结构域氨基酸序列的相似性较高。CsDREB-A4b转录因子为亲水性蛋白,理论相对分子质量为31 938.5,理论等电点为p I 5.91,总平均疏水性为-0.603,碱性、酸性、芳香族和脂肪族氨基酸的比例分别为12%、12%、7%和15%。在高温(38℃)胁迫处理前期,CsDREB-A4b基因的相对表达量显著高于胁迫处理前;在低温(4℃)胁迫处理下,CsDREB-A4b基因的相对表达量呈显著升高的趋势;在盐(200 mmol·L-1Na Cl)和干旱(200 g·L-1PEG)胁迫处理下,CsDREB-A4b基因的相对表达量呈先降低后显著升高的趋势。表明CsDREB-A4b基因参与‘安吉白茶’非生物胁迫的响应过程,且在不同胁迫条件下具有表达差异性。

A gene encoding DREB transcription factor was cloned from cDNA in leaf of cultivar‘Anjibaicha’ of Camellia sinensis （ Linn.） O. Ktze. by RT-PCR method, which was named as CsDREB-A4b. The result of sequence analysis shows that CsDREB-A4b gene contains an open reading frame with length of 873 bp, 290 amino acids are encoded, which has a conserved AP2 domain. By homologous evolutionary analysis with AP2/ERF family transcription factors from Arabidopsis thaliana （ Linn.） Heynh., CsDREB-A4b transcription factor belongs to A4 group in DREB subfamily. The result of multiple alignment shows that amino acid sequence of conserved domain in CsDREB-A4 b transcription factor has high similarity to that in DREB transcription factors from other plants, such as Ricinus communis Linn., etc. CsDREB-A4b transcription factor is hydrophilic protein, theoretical relative molecular mass is 31 938 . 5 , theoretical isoelectric point is pI 5 . 91 , grand average of hydrophobicity is -0. 603, and in which, percentages of basic, acidic, aromatic and aliphatic amino acids are 12%, 12%, 7% and 15%, respectively. In the early stage of high temperature （ 38 ℃） stress treatment, relative expression of CsDREB-A4b gene is significantly higher than that before stress treatment. Under low temperature （4 ℃） stress treatment, that of CsDREB-A4b gene appears a significantly increasing trend. Under salt （200 mmol·L-1 NaCl） and drought （200 g·L-1 PEG） stress treatments, that of CsDREB-A4b gene appears the trend of firstly decreasing and then significantly increasing. It is indicated that CsDREB-A4 b gene participates in response process of ‘Anjibaicha ’ to abiotic stress and shows differences in expression under conditions of different stress treatments.