Abstract：Cytochrome P450 reductase (CPR) is a kind of electron donor in the oxidation system, which is a rate-limiting enzyme in the cytochrome P450-mediated redox reactions. CPR is the key enzyme in oxidation reaction in vivo. In this study, two degenerate primers were designed according to the sequence of CPR gene from other species, and partial sequence of CPR gene from Matricaria recutita was obtained. By RACE technologies, the 2 272 bp full-length cDNA sequence of CPR gene from Matricaria recutita was isolated, and GenBank accession was KJ004519. The full length CDs of CPR contained 2 106 bp nucleotides, which encoded a protein of 701 amino acids. The CPR protein was closely clustered with Artemisia annua in a phylogenetic tree, and they had 94% similarity of the amino acid sequence. The transcriptional expression of CPR was analysed with quantitative Real-time PCR. The results showed that the chamomile CPR mRNA expression was the highest in disc flower. Bioinformatics analysis showed that they had the most intimate relationship between Matricaria recutita and Artemisia annua, for 94% similarity of CPR amino acid sequence. The structure of CPR included P450, flavin mononucleotide(FMN), flavin adenine dinucleotide(FAD) and nicotinamide adenine dinucleotide phosphate(NADP) binding domains; The expressions of CPR were detected from radial flower, disk flower, stem and leave by qRT-PCR in Matricaria recutita, and the results showed that the expression of CPR in disk flower was the highest, which was 20 times higher than leaves, while radial corolla and stems had little expression of CPR. In this study, we had cloned the CPR gene from chamomile the first time, as we know, CPR was a key enzyme in the oxidative modification process of plant terpenes. So our results of the study may provide a molecular basis for the further research of the functions of cytochrome P450 oxidoreductase system in terpenes biosynthetic pathway in chamomile.
