小桐子赤霉素20氧化酶的基因克隆及低温下表达分析

Gene Cloning and Cold-induced Expression Analysis of the Gene Encoding Gibberellin 20 Oxidase from Jatropha curcas

赤霉素20氧化酶是植物赤霉素生物合成的限速酶,决定有生物活性的GA1与GA4的合成量。基于先前获得的小桐子低温锻炼转录组数据,以小桐子幼苗的根为材料,采用RT-PCR技术克隆到小桐子赤霉素20氧化酶基因Jc GA20ox的c DNA序列(Gen Bank登录号KJ670150.1)。该c DNA全长1 307 bp,含有完整的开放阅读框(1 131 bp),编码376个氨基酸,分子量为43 k D,理论等电点为6.7。其推导蛋白属于2-ODD家族,包含2-酮戊二酸双加氧酶结构域(Fe2OG_OXY)。半定量RT-PCR表达分析显示,Jc GA20ox在小桐子各组织中都有表达,但表达水平具有组织特异性,在茎中表达量较高,且受低温诱导表达最显著,而在叶中表达量相对较低。

Gibberellin（GA）20 oxidase, a rate-limiting enzyme in GA biosynthesis, determines the amount of active GA forms, GA1 and GA4. Based on our previous transcriptome data of chilling-hardened Jatropha curcas, a new gene encoding gibberellin 20 oxidase（named Jc GA20ox）was cloned by RT-PCR from the root of J. curcas seedlings（Gen Bank accession number ：KJ670150.1）. The full-length c DNA of Jc GA20 ox was 1 307 bp, containing an entire open reading frame（ORF）of 1 131 bp. This ORF encoded a polypeptide of 376 amino acids with the molecular weight of 43 k D and the p I value of 6.7. Bioinformatics analysis showed that the Jc GA20 ox protein contained a Fe2＋and 2-oxoglutarate dioxygenase domain（Fe2OG_OXY）, belonging to the 2-ODD family. Semi-quantitative RT-PCR analysis revealed that Jc GA20 ox expressed differently in different tissues, with abundant and remarkably cold-induced expression in stem, but scarcely in leaves.