ABSTRACT
Objective: To clone the gene sequence of the key enzyme in synthesis pathway of terpenoids, 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) from Gentiana macrophylla (GmDXR) and to analyze its characteristic and expression. Methods: GmDXR gene was cloned and the sequence characterization was analyzed with bioinformatics methods, then the expression patterns of GmDXR were studied by real-time PCR. Results: GmDXR gene contained a completed open reading frame of 1 428 bp encoding 475 amino acids, GmDXR has high homology (≥85%) with DXR proteins from Rauvolfia verticillata, Lycopersicon esculentum, and other plants. Further analysis showed that GmDXR had non-transmembrane domain structure and signal peptide, which mainly located in the chloroplast. Quantitative PCR results showed that GmDXR mainly expressed in the leaves of G. macrophylla and could be induced by plant hormone such as methyl jasmonate (MeJA). Conclusion: GmDXR contains conserved structures of DXR protein. GmDXR expresses variously in different organs of G. macrophylla and could be induced by MeJA. It is very helpful for the future research on biosynthetic mechanism of iridoid compounds in G. macrophylla.