Phytotoxicity of graphene oxide on rice plants is concentration-dependent

Abstract

Graphene significantly affects seeds germination and seedling growth of food plants. Phytotoxicity tests by seeds germination and seedling growth are important means to detect toxicity of graphene oxide. We in this study assessed the effect of graphene oxide on rice plants at low concentration. Graphene oxide significantly inhibited water absorption during 3–6 h soaking, postponed seeds germination, but significantly decreased seeds germination rate under 10 μg/mL treatment. Graphene oxide showed most destructive effect on root than upper ground part, and severely restrained root development and increased chlorophyll content. Moreover, graphene oxide enhanced superoxide dismutase, catalase and peroxidase activities, and the change could alleviate oxygen damage. All these results indicate graphene oxide has some concentration-dependent phytotoxicity on seeds germination and seedling development, but also decreases damage by improving activities of antioxidant enzymes.