Jasmonates induce over-accumulation of methylputrescine and conjugated polyamines in Hyoscyamus muticus L. root cultures

Jasmonic acid (JA) and its methyl ester (MeJA) at concentrations ranging fr om 0.001 to 10 mu M provoked large increases in methylputrescine levels in normal and hairy roots of Hyoscyamus muticus L.; generally, levels of free putrescine and perchloric acid-soluble conjugated putrescine, spermidine an d spermine also increased dramatically. More C-14-putrescine was formed whe n hairy roots were incubated with labelled ornithine than with arginine; co njugated C-14- putrescine was also rapidly formed. In accord with these res ults, ornithine decarboxylase (EC 4.1.1.17) activity was higher than that o f arginine decarboxylase (EC 4.1.1.19), and MeJA enhanced these activities about two- and fourfold, respectively. Although treatment of root cultures with jasmonates enhanced precursor (putrescine, methylputrescine) levels an d accumulation of secondary metabolites such as acid-soluble conjugated di- /polyamines, it provoked only modest increases in tropane alkaloid tissue l evels.