Effects of Plant Bioregulators on the Production of Iridoid Derived Terpenoids in Valeriana wallichii and Fedia cornucopiae Cell Suspension Cultures

Abstract

D edicated to Professor Erich H ecker on the occasion o f his 60th birthdayPlant Bioregulators, V alepotriates, Suspension Cultures, Valeriana wallichii, Fedia cornucopiae Four plant bioregulators were tested for their effects on production o f valepotriates in Valeriana wallichii and Fedia cornucopiae cell suspension cultures. Concentrations o f more than 10 ppm reduced valepotriate yield. A t lower concentrations production was increased. For optimal activi ty, bioregulators had to be applied during early exponential growth, up to day 8 of the growth cycle. A t equimolar concentrations dim ethylm orpholinium bromide (4 ppm) and dimethylpiperidinium chloride (3 ppm) significantly im proved total valepotriates in V. wallichii (up to a n d i n F r n r n u r n n i n e (lin t o 5 0 % ) 4 -r l i r h l n r n n h p n n Y v ) -t r i > t h y l a m i n f ' ( 6 n n m ) a n r l 2-(3,5-diisopropylphenoxy)-triethylam ine (6.4 ppm ) increased valepotriate production in both cell cultures up to 40% . With dim ethylpiperidinium chloride and dimethylmorpholinium bromide the ratio o f m onoene to diene valepotriates in both cell systems was significantly shifted to the m onoene com pounds. A general use o f these bioregulators to increase production of terpenoid secondary m etabolites in plant tissue cultures is indicated.

Medicinal and Aromatic Plants VIII

“…The ratio of IV AL to VAL in the transformed roots was significantly shifted to VAL. Only with 10 ppm the valepotriate yield was slightly reduced (23%), thus confirming the results obtained previously by Förster and Becker (1987). In addition, there is a good correlation between the overall valepotriate content in the hairy roots and the diene/monoene ratio as shown in Fig.…”

“…The latter result was confirmed by a more detailed study on C. ruber, C. macrosiphon, and V officinalis (Violon et al 1984). Since the valepotriates have a terpenoid nature, Förster and Becker (1987) selected four PBRs [dimethylmorpholinium bromide (DMB), dimethylpiperidinium chloride (DPC), 2-(3,4-dichlorophenoxy)-triethylamine (DCPT A), and 2-(3,5-diisopropylphenoxy)-triethylamine (DIPTA)] and tested them for their effect on the production of valepotriates by colchicinetreated suspension cultures of V wallichii and Fedia cornucopiae Becker and Chavadej 1985). It was demonstrated that in vitro valepotriate production was closely re la ted to root differentiation and that light is not required for valepotriate biosynthesis.…”

“…5). The high accumulation of monoene derivatives could be explained by the fact that the conversion of diene from monoene, as postulated by Förster and Becker (1987), becomes the ratelimiting step in the biosynthesis ofthe diene valepotriates. The ratio of IV AL to VAL in the transformed roots was significantly shifted to VAL.…”

“…On the other hand, VAL was the major constituent of the hairy root eultures exeept in half-strength B5 medium supplemented with 2% sucrose. The effects offeeding DMI (Förster and Becker 1987) and TRIA (Ries et al 1977) as PBRs on growth and valepotriate yield were investigated for 40 days. A possible explanation for the high aceumulation ofV AL in hairy roots could be a partial inhibition ofthe enzymatic system involved in acetylation of position 7.…”