Isolation and characterization of a gene encoding farnesyl diphosphate synthase from \(\textit{Panax vietnamensis}\) Ha et Grushv

Panax vietnamensis Ha et Grushv. is a species of the genus Panax native to Central Vietnam, containing a family of triterpene saponins named ginsenosides. This group of biomolecules possesses valuable therapeutic properties against cancer, hepatitis, diabetes, inflammation as well as stress and anxiety. Farnesyl diphosphate synthase (FPS) is a key enzyme participating in the ginsenoside biosynthesis pathway. In this study, a FPS gene from P. vietnamensis (PvFPS) was isolated and characterized. The PvFPS cDNA contained an open reading frame of 1032 bp, encoding a polypeptide chain of 342 amino acid residues. Nucleotide sequence comparison showed that FPS was highly conserved among most species, with two Aspartate-rich motifs responsible for product chain length determination strongly sustained. PvFPS was closely related to those of the same genera and order and differed from those from other kingdoms. PvFPS expression was detected at a greater level in root tissues than in leaves in all ages. Our findings provided information concerning the properties of a crucial gene in the ginsenoside biosynthesis, thus enhancing our understanding of this important pathway.

High-Level Patchoulol Biosynthesis in Artemisia annua L.

Terpenes constitute the largest class of secondary metabolites in plants. Some terpenes are essential for plant growth and development, membrane components, and photosynthesis. Terpenes are also economically useful for industry, agriculture, and pharmaceuticals. However, there is very low content of most terpenes in microbes and plants. Chemical or microbial synthesis of terpenes are often costly. Plants have the elaborate and economic biosynthetic way of producing high-value terpenes through photosynthesis. Here we engineered the heterogenous sesquiterpenoid patchoulol production in A. annua. When using a strong promoter such as 35S to over express the avian farnesyl diphosphate synthase gene and patchoulol synthase gene, the highest content of patchoulol was 52.58 μg/g DW in transgenic plants. When altering the subcellular location of the introduced sesquiterpene synthetase via a signal peptide, the accumulation of patchoulol was observably increased to 273 μg/g DW. This case demonstrates that A. annua plant with glandular trichomes is a useful platform for synthetic biology studies.