Phytoalexin production in cultured carrot cells treated with pectinolytic enzymes

Abstract

6-Methoxymellein, a phytoalexin of carrot, was produced in cultured cells upon addition of partial hydrolysates of carrot cells obtained by treatment with purified endo-polygalacturonase or endo-pectin lyase. Direct addition of these enzymes to the cell culture also stimulated the accumulation of this 6-methoxymellein. When the hydrolysates obtained by these enzymes were subsequently treated within pectin esterase, the activity for the elicitation of 6-methoxymellein production decreased appreciably. These results suggest that pectinolytic enzymes release elicitor-active cell wall fragments from carrot cells and that a certain degree of esterification of the galacturonosyl moiety in these pectic polysaccharides is required for elicitor activity.