Expression Analysis of CoHMGS in and Subcellular Localization of the Enzyme It Encodes.

is a perennial deciduous tree or shrub. Its mature fruits are extracted and used in Traditional Chinese Medicine, called Shanzhuyu. The characteristic active components of include loganin and morroniside, which belong to iridoid glycosides. 3-Hydroxy-3-methylglutaryl-CoA synthase (HMGS) is a key enzyme in the cytoplasmic mevalonate pathway providing the precursor molecules isopentenyl pyrophosphate and dimethylallyl pyrophosphate for isoprenoid biosynthesis such as sterols, triterpenes, and their derivatives such as iridoid glycosides. Different concentrations of methyl jasmonate (MeJA) and ethephon (ETH) solutions were sprayed on seedlings, and the effect of hormones on gene expression was detected by real-time fluorescence quantitative PCR. The quantitative real-time PCR results showed that 750 mg/L ETH treatment had the most significant induction effect on gene expression. The HPLC analysis of extracts revealed that the treatment could also significantly increase the content of morroniside and loganin in the leaves of . By use of a CoHMGS-green fluorescent protein (GFP) fusion construct for heterologous expression in tobacco, laser scanning confocal microscopy revealed a cytoplasmic localization. This preliminary study of the gene could prepare the ground for more precisely elucidating the synthesis of secondary metabolite in .