Elicitor-induced Phenylalanine-Ammonia Lyase, Cinnamic Acid 4-Hydroxylase and $rho-Coumaroyl$ transferase Activity in Ephedra Distachya Cultures

Ephedra olistachya cultures have been known to accumulate $rho-coumaroylamino$ acids by elicitor treatment. Based on their chemical structures, the biosynthetic pathway of$rho-coumaroylamino$acids was postulated and phenylalanine ammonia-lyase (PAL), cinnamic acid 4-hydroxylase (4-CH) and p-coumaroyl CoA: D-Ala p-coumaroyltransferase ($rho-CT$) were supposed to be involved in the pathway. The time course inductions of these enzymes were investigated after treatment of yeast extract, yeast-derived mannan glycopeptide and D-Ala. They were detectable at only 4 hours and reached to their maximum level at 9 hours after onset of elicitor treatment. The activities of PAL and 4-CH were almost disappeared within 24 hours, however, that of $rho-CT$was remained up to 48 hours irrespective of the kind of elicitors. $rho-CT$ showed substrate specificity to D-Ala at crude enzyme extract level.