Mitigating Cadmium Toxicity in Maize Through Silicon Nanoparticles: Effects on Growth, Antioxidant Activity and Metal Accumulation

Cadmium (Cd) contamination in agricultural soils poses a serious threat to crop productivity and food security, necessitating effective mitigation strategies. This study investigates the role of silicon nanoparticles (SiNPs) in alleviating Cd-induced stress in maize (Zea mays L.) under controlled greenhouse conditions. Sterilized maize seeds were sown in sand-filled pots and treated with varying SiNP concentrations (0%, 0.75%, 1.5%, 3%, and 6%) with or without Cd (30 ppm). Physiological, biochemical, and antioxidant parameters were analyzed to assess plant responses. Results demonstrated that SiNPs significantly enhanced photosynthetic pigment concentrations, with chlorophyll-a, chlorophyll-b, and carotenoids increasing by 45%, 35%, and 50%, respectively, in the 6% SiNP + 30 ppm Cd treatment. Biochemical analyses revealed improved osmotic adjustment, as indicated by higher soluble protein (6.52 mg/g FW) and proline (314.43 µmol/g FW) levels. Antioxidant enzyme activities, including superoxide dismutase, catalase, and ascorbate peroxidase, were markedly higher in SiNP-treated plants, mitigating oxidative damage. Additionally, SiNPs reduced Cd accumulation in plant tissues, suggesting a protective role in limiting metal toxicity. These findings highlight SiNPs as a promising approach for enhancing maize resilience against Cd stress, with potential applications in sustainable agriculture for improving crop health in contaminated soils.