Molecular analysis of a type III polyketide synthase gene in Fallopia multiflora

Abstract

A type III polyketide synthase (PKS) cDNA and the corresponding gene (FmPKS) were isolated from the rhizomes of Fallopia multiflora (Thunb.) (Polygonaceae). The full-length FmPKS cDNA was 1,228 bp, containing an open reading frame of 1,137 bp encoding a 378 amino acid residues long protein. The coding sequence of the gene was interrupted by three introns, a different gene structure from most of the type III PKS genes studied so far containing only one intron at a conserved site, except for the recently cloned gene PcPKS2 from Polygonum cuspidatum. Phylogenetic analysis revealed that it shares a close relationship with Rheum tataricum stilbene synthase and formes a group with functionally diverse chalcone synthase-like enzymes. Southern blotting showed that there are three to four copies of the FmPKS gene in the genome. The expression pattern of the FmPKS transcript was determined by Northern blotting and high expression levels were detected in rhizomes and old stems, while the lowest levels were found in old leaves, a pattern that strongly correlates with the accumulation of the major bioactive principles called 2,3,5,4'-tetra-hydroxy-stilbene-2-O-β-D-glucoside, suggesting that FmPKS might play an important role in its biosynthesis.

Overexpression of a stilbene synthase gene from Fallopia multiflora causes trans-piceid accumulation in transgenic Arabidopsis

“…To our knowledge, this is the first report that an STS gene from F. multiflora transferred to other plants leads to stilbene accumulation. Considering the relevance of the FmSTS1 expression pattern with the distribution of THSG reported in our previous research (Sheng et al 2010), FmSTS1 may play a crucial role in stilbenes biosynthesis in F. multiflora and may directly affect THSG biosynthesis. Further research will focus on its transformation into F. multiflora cell line or hair root to confirm whether it can improve THSG production.…”

“…Our team has performed considerable research aimed at characterizing the THSG biosynthesis mechanism (Xia et al 2017). We previously showed that the expression pattern of FmSTS1 analyzed by Northern blot corresponded well with the THSG distribution in different tissues of F. multiflora, implying that FmSTS1 may play a crucial role in THSG biosynthesis (Sheng et al 2010). In the current study, the anticipated THSG was not detected in the transgenic Arabidopsis.…”

“…In our previous study, a presumed STS gene FmSTS1 was isolated from F. multiflora (Sheng et al 2010). To further confirm its function on the stilbene biosynthesis in F. multiflora, we inserted this gene into Arabidopsis thaliana L. genome for heterologous expression.…”

Relevant Enzymes, Genes and Regulation Mechanisms in Biosynthesis Pathway of Stilbenes

“…Firstly, the possible relevant genes or enzymes should be identified from Polygonum multiflorum. The clone of a type Ш polyketide synthase gene (FmPKS) using oligonucleotide primers designed for regions conserved amongst STS (with special attention given to the closely-related species of the Polygonaceae family) in Fallopia multiflora have be conducted by Shujing Sheng [51]. The FmPKS has been identified strongly correlates with the accumulation of stilbene glucoside by using Northern blotting, RNA inference and over expression, suggesting that FmPKS might play an important role in its biosynthesis.…”

Isolation of biosynthesis related transcripts of 2,3,5,4'-tetrahydroxy stilbene-2-O-β-D-glucoside from Fallopia multiflora by suppression subtractive hybridization

“…Up to now, no enzyme was found to catalyze the biosynthesis of THSG. Sheng et al THSG was still not detectable in transgenic Arabidopsis thaliana in which FmPKS was inserted and expressed [11]. Shao et al showed precursor feeding of methyl jasmonate and salicylic acid in suspension cultures of F. multiflora that could increase THSG production [12].…”