小桐子低温诱导查耳酮合酶基因的克隆及其表达分析

Cloning and Expression Analysis of Chilling-induced Chalcone Synthase Gene from Jatropha curcas

摘要:

为了解查耳酮合酶在小桐子(Jatropha curcas)抗冷性形成中的作用, 基于小桐子低温锻炼转录组和数字基因表达谱数据, 克隆了低温新诱导表达的小桐子查耳酮合酶基因(JcCHS), 并分析了该基因的表达特性和功能。结果表明, JcCHS 基因的cDNA全长为1386 bp, 包含完整开放阅读框(ORF) 1170 bp, 编码389个氨基酸, JcCHS的理论分子量为42.2 kDa、等电点为6.53, 与蓖麻CHS 蛋白序列的相似性高达93.6%, 具有III 型聚酮合酶家族保守的查耳酮合酶/ 对苯乙烯合酶结构域。半定量RTPCR分析表明, JcCHS 在小桐子各组织中都有表达, 其中根的表达量较高。JcCHS 基因的表达能在一定程度上提高重组酵母菌的低温抵抗能力, 这说明JcCHS 基因可能参与了小桐子的抗低温响应。

关键词:小桐子;查耳酮合酶;低温;诱导;表达;基因克隆;酵母

Abstract:

In order to understand the function of chalcone synthase in cold resistance of Jatropha curcas, a chilling-induced chalcone synthase gene, named as JcCHS, was cloned from J. curcas based on data of transcriptome and digital gene expression profiling (DGE), and the expression patterns were analyzed by semiquantitative RT-PCR. The results showed that the full length of JcCHS cDNA was 1386 bp, with entire open reading frame (ORF) of 1170 bp encoding 389 amino acids. The theoretical molecular weight of JcCHS was 42.2 kDa with pI of 6.53. JcCHS protein shared 93.6% identity with CHS from Ricinus communis (Euphorbiaceae), and belong to the type-III polyketide synthase family containing conserved domains of chalcone synthase/styrene synthase. The expression of JcCHS was detected in all tissues with the highest expression in root. In addition, the over-expression of JcCHS in yeast enhanced its resistance to low temperature. So, it was suggested that JcCHS gene would involve in the cold-resistance formation in J. curcas.

Key words:Jatropha curcas;Chalcone synthase;Low temperature;Induction;Expression;Gene clone;Yeast