Induction of N-p-Coumaroyloctopamine in Potato Tuber Disks by β-1,3-Glucooligosaccharide

Abstract

N-p-Coumaroyloctopamine (PCO) was identified as an induced phenolic substance in potato (Solanum tuberosum) tuber disks which had been treated with a hyphal wall component from a blight fungus, Phytophthora infestans. The induction was also caused by treating the disks with laminarin, an algal β,3-glucooligosaccharide, in a dose-dependent manner. Maximum level of induction was about 150 µg (500 nmol)/g tissue. A purified β-1,3-glucosaccharide with a degree of polymerization of 7 was significantly active at 1.2 mM, although the amount of induced amide was smaller than that induced by laminarin itself. The fatty acid elicitor, arachidonic acid, was not as effective for inducing PCO. This response of potato tuber disks may serve for elucidating the action mechanism of oligosaccharides that can modify plant secondary metabolism. © 1998, Pesticide Science Society of Japan. All rights reserved.