Cadmium (Cd) toxicity severely impairs rice growth and poses risks to food safety due to its high bioaccumulation potential. This study investigates the mechanisms by which graphitic carbon nitride (g-C₃N₄) mitigates Cd-induced phytotoxicity in rice seedlings under hydroponic conditions. g-C₃N₄ was synthesized via thermal decomposition of urea at 550 °C for 4 hours under argon, resulting in a layered, crystalline material confirmed by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. SEM images revealed irregular, sheet-like structures with lateral dimensions in the nanometer range. XRD patterns displayed two distinct peaks at ~13° and 27°, corresponding to the (100) and (002) crystal planes of g-C₃N₄, confirming its graphitic structure. FTIR spectra exhibited characteristic absorption bands at 810 cm⁻¹ and 1200–1600 cm⁻¹, attributed to triazine ring vibrations and CN heterocycle stretching, respectively.
Rice seedlings were exposed to 20 mg/L CdCl₂ alone or combined with g-C₃N₄ at concentrations of 20 and 200 mg/L for 20 days. Results showed that 200 mg/L g-C₃N₄ significantly enhanced root and shoot biomass, increasing fresh weight by 21% and 12%, respectively, compared to the control. In Cd-stressed plants, g-C₃N₄ reduced growth inhibition, improving shoot and root length by 14% and 42%, respectively. Crucially, g-C₃N₄ decreased Cd accumulation in roots by 14% and in shoots by 23%, suggesting effective adsorption or restriction of Cd uptake.
The study further examined physiological and biochemical responses.58-05-9 medchemexpress Cd stress led to elevated reactive oxygen species (ROS) levels and oxidative damage, but g-C₃N₄ supplementation attenuated this effect.1818885-28-7 Molecular Weight Additionally, g-C₃N₄ restored nitrogen metabolism disrupted by Cd: it increased nitrogen content in shoots and lowered the C/N ratio, counteracting Cd-induced nitrogen deficiency.PMID:30968963 Nitrogen is essential for chlorophyll synthesis, enzyme activity, and protein production—processes impaired under Cd stress. By enhancing nitrogen assimilation, g-C₃N₄ supports photosynthetic efficiency and metabolic stability.
Moreover, g-C₃N₄ may influence root cell wall integrity and ion transport pathways, reducing Cd translocation from roots to shoots. Its surface functional groups likely bind Cd²⁺ ions, preventing their entry into plant tissues. The material’s photocatalytic properties might also contribute to ROS scavenging, although this requires further investigation.
These findings demonstrate that g-C₃N₄ alleviates Cd toxicity through multiple mechanisms: physical adsorption of Cd, regulation of nutrient homeostasis, and protection against oxidative stress. Its low cost, environmental compatibility, and effectiveness at 200 mg/L make it a promising candidate for sustainable agricultural applications. This work establishes a strong foundation for using g-C₃N₄ as a green nanoremediation agent in contaminated soils, offering a viable strategy to safeguard crop productivity and food quality.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
