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

Hydrogen peroxide (HO) 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 HO frequently occur globally, few studies have evaluated its toxicity and risk to soil ecosystems. Herein, accidental exposure to HO 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 HO exposure, distance from HO source, and duration post exposure. Plants exposed to high concentrations and large amounts of HO at a close distance were most damaged; their photosynthetic activities and polyphenolic compound levels significantly decreased compared to the controls. HO 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 HO 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 HO exposure in V. radiata. Our results highlight the risk of HO and serve as a reference for chemical accidents.