Physiological response of rice to graphene oxide under cadmium chloride stress

Cadmium (Cd) is a highly toxic heavy metal commonly introduced into agricultural soils through phosphate fertilizers. Cadmium accumulation poses serious risks to human health, crop productivity, and environmental sustainability. Although the toxic effects of Cd on plant development are well documented, effective and sustainable strategies to mitigate its impact on seed germination and early plant growth remain limited. Nanomaterials such as graphene oxide (GO) demonstrated potential in alleviating abiotic stress, but application in Cd-contaminated agricultural systems requires further investigation. Therefore, the aim of this study was to examine the potential of GO as a possible mitigator of adverse Cd-initiated effects on seed germination and initial growth of rice (<i>Oryza sativa</i> L.) seedlings. Rice seeds were treated with varying concentrations of GO (0 to 500 mg/L), Cd chloride (0 to 0.4 mM), and combination of GO + Cd chloride simultaneously. The experiment was conducted on a germitest paper, where the rolls were kept for 7 days in a germination chamber (25 ± 2 °C and 12 hr light). The germination and seedling growth were subsequently assessed. Cadmium exposure inhibited seed germination and early seedling development, particularly at concentrations from 0.1 mM. Graphene oxide, on the other hand, proved to be a suitable alternative to mitigate Cd-induced stress, showing a significant enhanced germination at concentrations of up to 250 mg/L. Graphene oxide demonstrated potential as a protective agent against Cd-induced toxicity in rice seeds, suggesting its promising application in improving crop resilience in metal-contaminated environments.