23 - Biostimulants in the alleviation of metal toxicity: conclusion and future perspective

Abstract

Heavy metals are toxic for the growth and development of plants and can accumulate in the soil, leading to soil and water contamination. Biostimulants have been shown to alleviate heavy metal stress in plants through a variety of mechanisms, including enhancing plant nutrient uptake, improving antioxidant defense mechanisms, and increasing the activity of plant growth-promoting microorganisms in the soil. Seaweed extract is rich in bioactive compounds such as polysaccharides, amino acids, and plant growth hormones that can enhance plant growth and stress tolerance. Research has revealed that seaweed extract can reduce heavy metal toxicity in plants by increasing plant nutrient uptake, improving photosynthesis, and enhancing antioxidant defense mechanisms. In addition to humic acid and seaweed extract, other biostimulants such as plant growth-promoting bacteria and fungi, mycorrhizal fungi, and silicon have also been investigated for their potential to alleviate heavy metal stress in plants. However, the use of biostimulants in agriculture is still in its early stages, the research findings suggest that biostimulants could be a promising solution for improving plant growth and resilience to heavy metal stress in a sustainable manner.