Efficacy of 24-epibrassinolide and melatonin to enhance phytoremediation potential of Trigonella foenum-graecum L

The study examined the effects of industrial solid waste (ISW) and the potential of 24-epibrassinolide, melatonin, and their combination to enhance the phytoremediation of the fenugreek plant. Trigonella foenum-graecum L. plants were grown in soils amended with varying concentrations of ISW (0, 5, 10, and 15%) and treated with 24-epibrassinolide, melatonin, and their combination for 60-days. The physicochemical properties of the ISW were analyzed before and after plant harvesting. The results showed that exposure to ISW toxicity significantly reduced the growth parameters and altered the characteristics of the fenugreek plants. Melatonin and epibrassinolide boosted antioxidant activity and mitigated metal-induced stress. Metal analysis showed a substantial reduction in concentrations across all solid waste treatments, suggesting successful metal remediation. The lowest metal uptake was observed at 5% solid waste concentration, while the highest was at 10% concentration. Fenugreek accumulates lead highly compared with nickel and cadmium (Pb > Ni > Cd). Melatonin applied at a 10% concentration of industrial solid waste proved to be a highly effective stimulant in mitigating metal stress in fenugreek plants grown in metal-contaminated soil, by significantly reducing metal uptake and translocation to various parts of the plant, thereby promoting plant growth and development in polluted soil. Combining phytoremediation with biochar technology offers a potent solution for effectively cleaning heavy metal-contaminated soils. Biochar enhances phytoremediation by immobilizing heavy metals after using 24-Epibrassinolide, promoting microbial diversity, and improving soil health, creating an optimal environment for plant growth and effective cleanup. Biochar’s popularity as a soil amendment has grown due to enhanced soil fertility, water retention, pH balance, nutrient availability, carbon sequestration, microbial activity, and pollution remediation. 24-Epibrassinolide has not been tried before and hence proved to be a potential growth regulator to enhance phytoremediation.