INDUCTION OF 6-METHOXYMELLEIN AND 6-HYDROXYMELLEIN PRODUCTION IN CARROT CELLS

6-Methoxymellein, a phytoalexin of carrot, and 6-hydroxymellein, its presumed biosynthetic precursor, were isolated from carrot root slices infected with Sclerotium rolfsii and Fusarium solani. Elicitation of both 6-methoxymellein and 6-hydroxymellein synthesis was achieved also in carrot cell suspension cultures by direct addition of pectinolytic enzymes such as Aspergillus niger pectinase highly purified Fusarium moniliforme endo-polygalacturonase (EC. 3.2.1.15). 6-Hydroxymellein was preferentially detected inside the cells while 6-methoxymellein was always found in the culture medium. Changes in pH values at the moment of elicitation of carrot cell suspension cultures influenced the amounts of both phytoalexins synthesized. © 1990.