Seed priming with graphene oxide improves cadmium stress tolerance in maize

Cadmium (Cd) is a highly toxic heavy metal that impairs seed germination and early plant development, posing a major constraint to agricultural productivity and environmental quality. Although several approaches aimed to reduce metal-induced stress in crops, limited information is available on whether carbon-based nanomaterials, such as graphene oxide (GO), might mitigate Cd-initiated toxicity during the earliest stages of plant growth. The aim of this study was to investigate the potential of GO to diminish the harmful effects attributed to Cd exposure on maize seed germination and seedling establishment. Maize seeds were exposed for 7 days to Cd and GO, applied either individually or in combination, under controlled germination conditions (25°C, 12 hr photoperiod). Germination percentage (G%), seedling length, and dry biomass were subsequently measured. Cd exposure markedly reduced germination and inhibited early growth, whereas GO alone exhibited no phytotoxicity and even stimulated increases in seedling length and dry mass. When applied together, GO alleviated the detrimental effects attributed to Cd, treatment particularly at concentrations of 125 mg/L and higher for germination, and 250 mg/L for growth parameters. These findings indicate that GO may mitigate Cd-induced stress and support early maize development, suggesting GO as a potential mitigating agent in metal-contaminated environments and as a promising tool for sustainable agricultural management.