采用RT-PCR 方法从茶树[Camellia sinensis (Linn.) O. Ktze.]品种‘安吉白茶’ (‘Anjibaicha’)叶片的cDNA 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pI5.91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^-1 NaCl)和干旱(200 g·L^-1 PEG)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-A4b 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-1PEG) stress treatments, that of CsDREB-A4b gene appears the trend of firstly decreasing and then significantly increasing. It is indicated that CsDREB-A4b gene participates in response process of ‘Anjibaicha’to abiotic stress and shows differences in expression under conditions of different stress treatments.