Cloning and expression analysis of 1-deoxy-D-xylulose-5-phosphate reductoisomerase gene (CcDXR1)in Cinnamomum camphora (L.) Presl / 药学学报

ABSTRACT

1-Deoxy-D-xylulose-5-phosphate reductoisomerase (DXR) is the second rate-limiting enzyme of terpenoid biosynthesis in the methylerythritol-4-phosphate pathway. According to the transcriptome database of Cinnamomum camphora, the DXR cDNA was cloned by rapid amplification of cDNA ends (RACE) from C. camphora, and was named CcDXR1 (GenBank numberKU886266). The ORF of CcDXR1 is composed of 1 413 bp, and it encodes 470 amino acids. The bioinformatics analysis suggests that the molecular weight of the encoded protein is 51.1 kD and the theoretically isoelectric point is 6.62, and there is no signal peptide and transmembrane structure in putative protein. The analysis of sequence alignment and phylogenetic tree showed that the CcDXR1 belonged to the DXR family. The results of the realtime PCR indicated that expression level of CcDXR1 in mature leaves was higher than tender leaves, which in roots was similar to leaves and the lowest in branches. The camphor is divided into five chemotypes, according to the main chemical compounds in C. camphora. It also showed that the expression level of CcDXR1 in borneol C. camphora was highest than that in cineol, iso-nerolidol, camphor and linalool. Our results revealed that the expression level of CcDXR1 exhibits diversity among plant tissues, growth periods and five chemical types, and the research provides foundation for further study of the terpenoids biosynthetic pathway in C. camphora.