methyl-jasmonate and rhodioloside

Sesame (Sesamum indicum L.) plants contain large amounts of acteoside, a typical phenylethanoid glycoside (PhG) that exhibits various pharmacological activities. Although there is increasing interest in the biosynthesis of PhGs for improved production, the pathway remains to be clarified. In this study, we established sesame-cultured cells and performed transcriptome analysis of methyl jasmonate (MeJA)-treated cultured cells to identify enzyme genes responsible for glucosylation and acylation in acteoside biosynthesis. Among the genes annotated as UDP-sugar-dependent glycosyltransferase (UGT) and acyltransferase (AT), 34 genes and one gene, respectively, were upregulated by MeJA in accordance with acteoside accumulation. Based on a phylogenetic analysis, five UGT genes (SiUGT1-5) and one AT gene (SiAT1) were selected as candidate genes involved in acteoside biosynthesis. Additionally, two AT genes (SiAT2-3) were selected based on sequence identity. Enzyme assays using recombinant SiUGT proteins revealed that SiUGT1, namely, UGT85AF10, had the highest glucosyltransferase activity among the five candidates against hydroxytyrosol to produce hydroxytyrosol 1-O-glucoside. SiUGT1 also exhibited glucosyltransferase activity against tyrosol to produce salidroside (tyrosol 1-O-glucoside). SiUGT2, namely, UGT85AF11, had similar activity against hydroxytyrosol and tyrosol. Enzyme assay using the recombinant SiATs indicated that SiAT1 and SiAT2 had activity transferring the caffeoyl group to hydroxytyrosol 1-O-glucoside and salidroside (tyrosol 1-O-glucoside) but not to decaffeoyl-acteoside. The caffeoyl group was attached mainly at the 4-position of glucose of hydroxytyrosol 1-O-glucoside, followed by attachment at the 6-position and the 3-position of glucose. Based on our results, we propose an acteoside biosynthetic pathway induced by MeJA treatment in sesame.

Topics: Glucose; Glucosides; Glucosyltransferases; Glycosides; Glycosyltransferases; Phylogeny; Recombinant Proteins; Sesamum; Sugars; Uridine Diphosphate

To provide a new material for producing the Rhodiolasachalinensis products, the effect of methyl jasmonate (MeJA) on callus biomass and effective compound accumulation of Rhodiolasachalinensis was studied.. The calluses-cultured in 3 L-air lift balloon type bioreactor were treated with MeJA after 20 d of bioreactor culture and the effect of MeJA concentration and treatment days on callus biomass, salidroside or polysaccharide accumulation and superoxide dismutase (SOD) and peroxidase (POD) activities were investigated.. The callus biomass was not significantly different after MeJA treatment (125) for 0-6 d but obviously decreased after 6 d treatment. The maximum salidroside or polysaccharide contents and SOD or POD activities were found after 4 d treatment of MeJA. MeJA concentration significantly affected callus biomass and effective compound accumulation, biomass decreased at MeJA concentrations higher than 125 μmol x L(-1). However, the effective compound contents were determined at higher MeJA concentration, and the highest salidroside and polysaccharide accumulation was found at 225 and 275 μmol x L(-1) MeJA, respectively and the maximum SOD and POD activities was found at 225 μmol x L(-1) MeJA. The effective compound contents in callus were compared with field-grown plants. Salidroside contents in calluses were 1.1-fold and 2. 4-fold more than in plant roots and stem or leave, respectively. Polysaccharide content in calluses were 3. 6-fold and 8.0-fold more than in plant roots and stem or leave, respectively.. Salidorside and polysaccharide in Rhodiolasachalinensiscalluses improved by MeJA treatment, 225 μmol x L(-1) MeJA and 4 d treatment were optimal. The effective compound contents in callus were obviously higher than in field-grown plants. Therefore, bioreactor culture is efficient for obtaining mass effective compounds of Rhodiolasachalinensis by culturing calluses. This method could provide an alternative material source for production of Rhodiolasachalinensis products.

Topics: Acetates; Biomass; Bioreactors; Cyclopentanes; Glucosides; Oxylipins; Peroxidase; Phenols; Polysaccharides; Rhodiola; Superoxide Dismutase

Salidroside, the 8-O-β-D-glucoside of tyrosol, is a novel adaptogenic drug extracted from the medicinal plant Rhodiola sachalinensis A. Bor. Due to the scarcity of R. sachalinensis and its low yield of salidroside, there is great interest in enhancing production of salidroside by biotechnological manipulations. In this study, two putative UDP-glycosyltransferase (UGT) cDNAs, UGT72B14 and UGT74R1, were isolated from roots and cultured cells of methyl jasmonate (MeJA)-treated R. sachalinensis, respectively. The level of sequence identity between their deduced amino acid sequences was ca. 20%. RNA gel-blot analysis established that UGT72B14 transcripts were more abundant in roots, and UGT74R1 was highly expressed in the calli, but not in roots. Functional analysis indicated that recombinant UGT72B14 had the highest level of activity for salidroside production, and that the catalytic efficiency (Vmax/Km) of UGT72B14 was 620% higher than that of UGT74R1. The salidroside contents of the UGT72B14 and UGT74R1 transgenic hairy root lines of R. sachalinensis were also ∼420% and ∼50% higher than the controls, respectively. UGT72B14 transcripts were mainly detected in roots, and UGT72B14 had the highest level of activity for salidroside production in vitro and in vivo.

Topics: Acetates; Cyclopentanes; Glucosides; Glycosyltransferases; Oxylipins; Phenols; Phylogeny; Plant Roots; Plants, Genetically Modified; Recombinant Proteins; Rhodiola