Effects of feeding Clostera anachoreta on hydrogen peroxide accumulation and activities of peroxidase, catalase, and ascorbate peroxidase in Populus simonii × P. pyramidalis ‘Opera 8277’ leaves

Abstract

In response to Clostera anachoreta larvae attack, poplar (Populus simonii × P. pyramidalis ‘Opera 8277’) leaves produced a high level of hydrogen peroxide (H2O2). Histochemical localization revealed that H2O2 was mainly localized in herbivore-wounded zones and might spread through the veins. The activities of three H2O2-scavenging enzymes, i.e., peroxidase (POD), ascorbate peroxidase (APX), and catalase (CAT), were also enhanced in herbivore-wounded leaves, and exhibited an opposite pattern to the accumulation of H2O2. It was found that diphenylene iodonium chloride (DPI, a special inhibitor of NADPH oxidase) treatment significantly inhibited the accumulation of H2O2 induced by herbivory damage. Moreover, DPI treatment led to an obvious decrease in the activities of POD, APX, and CAT. The results indicated that NADPH oxidase contributed to the accumulation of H2O2 and the increase in activities of H2O2-scavenging enzymes in poplar leaves induced by herbivory damage. The balance between H2O2-production pathway and H2O2-scavenging enzymes led to the tolerable level of H2O2 acting in P. simonii × P. pyramidalis ‘Opera 8277’ cuttings in response to herbivory damage.