Abstract:

A new method was developed to determine the acting paths of elicitors based on the analysis of intermediate response mode in suspension cultures. It was found that the acting path of an elicitor, defined as the biosynthesis step whose rate was significantly enhanced upon the addition of the elicitor, was located between two adjacent intermediates whose concentrations changed in opposite directions. The validity of this method was verified in the biosynthesis of taxol from suspension cultures of Taxus chinensis (Pilg.) Rehd. var. mairei (Lemee et Levl.) Cheng et L. K. Fu. The acting paths of methyl jasmonate, silver nitrate and ammonium citrate were determined to be located at the step from baccatin Ⅲ to 10-deacyl taxol. There are three possibilities for salicylic acid and arachidonic acid: (1) improving the biosynthesis of 10-deactyl baccatin Ⅲ (10-DAB), (2) inhibiting the degradation of taxol and (3) inhibiting the degradation of cephalomannine. But it is difficult to elucidate the exact acting paths of these two elicitors based on the present method.

Key words: acting path, elicitor, intermediate response mode, suspension culture, taxol, Taxus chinensis var. mairei