Cloning and Expression Analysis of 3-Hydroxy-3-Methylglutaryl-CoA Reductase Gene from Matricaria chamomilla

Abstract

Chamomile (Matricaria chamomilla L.) is renowned for its production of essential oils, which major components are sesquiterpenoids. As the important enzyme in the sesquiterpenoid biosynthesis pathway, the enzyme 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) catelyzes the first committed step of isoprenoids biosynthesis in MVA pathway. In this study, a full-length cDNA encoding HMGR (designated as McHMGR, GenBank Accession No. KX925561) was successfully isolated from leaves of M. chamomilla by PCR. The full-length cDNA of McHMGR was 2276 bp long and contained a 1743 bp open reading frame (ORF) encoding a 580-amino-acid protein. The sequence of the McHMGR protein was highly homologous to those of HMGR proteins from other plant species. Phylogenetic tree analysis indicated that McHMGR shared the same ancestor in evolution with HMGRs and had a further relationship with other Dicotyledoneae species. qRT-PCR analysis revealed that the expression level of McHMGR is highest in the flowers and lowest in the stems. The isolation and characterization of McHMGR gene will be helpful to further study the role of McHMGR gene in the biosynthesis of sesquiterpenoids on M. chamomilla.