Involvement of reactive oxygen species in the induction of (S)-N-p-coumaroyloctopamine accumulation by beta-1,3-glucooligosaccharide elicitors in potato tuber tissues.

Treatment of potato tuber tissues with beta-1,3-glucooligosaccharide induces accumulation of (S)-N-p-coumaroyloctopamine (p-CO). We examined the role of reactive oxygen species (ROS) and nitric oxide (NO) in the signal transduction leading to p-CO accumulation. Induction was suppressed by an NADPH-oxidase inhibitor, diphenyleneiodonium chloride, and oxygen radical scavengers. H2O2 was generated in the tuber tissue within a few minutes of treatment with beta-1,3-glucooligosaccharide. On the other hand, treatment with NO specific scavenger, nitric oxide synthase inhibitor, and serine protease inhibitor did not inhibit p-CO induction. Our findings suggest that ROS generated by the action of NADPH-oxidase play an important role in this system, while NO and serine protease are unlikely to be involved in this process.