Accumulation of phenolic acid conjugates and betacyanins, and changes in the activities of enzymes involved in feruloylglucose metabolism in cell-suspension cultures of Chenopodium rubrum L.

Abstract

Cell-suspension cultures of Chenopodium rubrum accumulate various soluble secondary phenolic metabolites such as the hydroxybenzoic acid glycosides 4-hydroxybenzoic acid-β-glucoside, vanillic acid-β-glucoside, the hydroxycinnamic acid acylglycosides 1-O-(4-coumaroyl)-β-glucose, 1-O-feruloyl-β-glucose, 1-O-sinapoyl-β-glucose and 1-O-feruloyl-(β-1,2-glucuronosyl)-β-glucose, the hydroxycinnamic acid amide N-feruloylaspartate, and the betacyanins betanin, amaranthin and celosianin II. In addition, accumulation of the insoluble cell wall-bound hydroxycinnamic acids with ferulic acid as the major component occurs parallel to culture growth. The changes of three pivotal enzymatic activities, all O-transferases which are involved in the formation of the dominant ferulic acid conjugates, were determined. These are (i) uridine 5'-diphosphate(UDP)glucose-hydroxycinnamic acid O-glucosyltransferase (EC 2.4.1), (ii) UDP-glucuronic acid:1-O-hydroxycin-namoyl-β-glucose O-glucuronosyltransferase (EC 2.4.1) and (iii) 1-O-hydroxycinnamoyl-β-glucose:amaranthin O-hydroxycinnamoyltransferase (EC 2.3.1). The patterns of metabolite accumulation associated with these enzyme activities show that the hydroxycinnamic acid-glucose esters play a central role as metabolically active intermediates in the secondary metabolism of Ch. rubrum. Two cell lines of this culture (CH, CHN), differing in their betacyanin content, were compared with respect to this metabolism. A markedly higher total betacyanin content in the CHN line might possibly be the consequence of an increased supply of the key precursor for betalain biosynthesis, i.e. 3,4-dihydroxyphenylalanine (DOPA). In addition, the enhanced accumulation of celosianin II in the CHN line correlates well with a higher activity of the enzyme catalyzing the transfer of ferulic acid from 1-O-feruloyl-β-glucose to amaranthin.

Tyrosinase involved in betalain biosynthesis of higher plants

“…f.) N.E.Br. (Heuer et al 1996), Chenopodium rubrum L. (Bokern et al 1991) and Phytolacca americana L. were cultivated as described earlier .…”

Hydroxycinnamoyltransferases in plant metabolism

“…Other glucosyltransferases with wide substrate acceptances have been identified from other plants, e.g. from tobacco accepting hydroxycinnamic acids as well as coumarins (Fraissinet-Tachet et al 1998), tomato or Chenopodium rubrum (Bokern et al 1991). The tomato enzyme (E.C.…”

Physiological and biochemical responses of in vitro Fusarium oxysporum f.sp. niveum to benzoic acid

“…Vol. 54 BoA is one of the phytotoxic allelochemicals produced in plant root exudates, secondary metabolites inside the plant (Bolwell et al 1986;Wu et al 2001), and has been suggested to be involved in the cell wall extensibility that plays key roles in cell defense (Wallace and Fry 1999;Bokern 1991;Locher et al 1994). The BoA effect on Saccharomyces cerevisiae, Pichia anomala, Issatchenkia occidentalis, Candida diddensiae, Mollisia sp., Penicillium commune, Mortierella sp., Trichoderma koningii, Trichoderma sp., Phoma herbarum and Lactobacillus plantarum has been investigated (Arroyo-Lopez et al 2008;Rodriguez et al 2008;Hughes et al 2007).…”