论文部分内容阅读
目的从药用植物秦艽Gentiana macrophylla中克隆了萜类成分合成途径的关键酶——5-磷酸脱氧木酮糖还原异构酶(1-deoxy-D-xylulose 5-phosphate reductoisomerase,DXR)基因,分析其序列特征及表达方式。方法克隆了秦艽DXR基因(GmDXR),分析了GmDXR编码蛋白序列的特征,并采用实时定量分析了GmDXR的表达模式。结果秦艽GmDXR基因包含1个完整的长1 428 bp的ORF框,编码475个氨基酸;GmDXR与萝芙木、番茄等植物DXR蛋白具有很高的同源性(≥85%),无跨膜结构域、信号肽等结构,主要定位于叶绿体中。定量PCR结果显示,GmDXR主要在秦艽的叶中进行表达,受到植物激素茉莉酸甲酯(methyl jasmonate,MeJA)的诱导。结论 GmDXR含有DXR蛋白的保守结构特征;在秦艽不同器官中GmDXR基因表达不同,且受到MeJA的诱导。该研究为今后研究秦艽环烯醚萜类化合物的生物合成机制提供了依据。
OBJECTIVE: To clone the gene of 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR), a key enzyme involved in the synthesis of terpenoids, from Gentiana macrophylla. Its sequence characteristics and expression. Methods GmDXR gene was cloned and analyzed. The characteristics of GmDXR coding protein sequence were analyzed and the expression pattern of GmDXR was analyzed by real-time quantitative analysis. Results The GmDXR gene of Gentiana macrophylla contains 1 complete ORF of 1 428 bp and encodes 475 amino acids. GmDXR has high homology (> 85%) with plant DXR of Rauwolfia and tomato, and has no transmembrane structure Domain, signal peptide and other structures, mainly located in the chloroplast. Quantitative PCR results showed that GmDXR was mainly expressed in the leaves of Gentiana macrophylla, and was induced by the plant hormone methyl jasmonate (MeJA). Conclusion GmDXR contains the conserved structural features of DXR protein. The expression of GmDXR gene is different in different organs of Gentiana macrophylla, and is induced by MeJA. This study provides the basis for the future study on the biosynthesis mechanism of iridoid compounds of Gentiana macrophylla.