Effects on photosynthesis and polyphenolic compounds in crop plant mung bean (Vigna radiata) following simulated accidental exposure to hydrogen peroxide.

Abstract

Hydrogen peroxide (H2O2) is a strong oxidizer and bleaching agent included in the list of substances requiring accident preparedness by the National Chemical Information System, Korea. Although chemical accidents related to H2O2 frequently occur globally, few studies have evaluated its toxicity and risk to soil ecosystems. Herein, accidental exposure to H2O2 was simulated in a microcosm including crop plant mung bean (Vigna radiata), and its long-term effects on photosynthetic activities and polyphenolic compounds were measured. Plants were evaluated based on the concentration and amount of H2O2 exposure, distance from H2O2 source, and duration post exposure. Plants exposed to high concentrations and large amounts of H2O2 at a close distance were most damaged; their photosynthetic activities and polyphenolic compound levels significantly decreased compared to the controls. H2O2 consistently damaged plants and affected their activities, but plants with minor damage recovered their photosynthetic activities and polyphenolic compound levels. Additionally, moderate oxidative stress from H2O2 exposure induced the synthesis of polyphenolic antioxidants including flavonol and anthocyanin. Thus, we suggest that flavonol and anthocyanin levels are the most sensitive indicators of adverse effects of H2O2 exposure in V. radiata. Our results highlight the risk of H2O2 and serve as a reference for chemical accidents.