Biostimulants as modulators of nutrient transporter activity in crops

Global demand for food production continues to rise, necessitating sustainable agricultural practices to enhance crop yield and nutritional quality. In these circumstances, fertilizers play a major role; however, excessive application of fertilizers leads to water pollution, soil degradation, and nutrient leaching, and also contributes to the emission of greenhouse gases. Overdependence on chemical fertilizers influences the soil microbiome, leads to soil acidification and long-term soil fertility, and ultimately reduces nutrient transporter activity. In contrast, biostimulants enhance nutrient use efficiency by upregulating transporters and improving soil structure through organic compounds such as alginates or humic acids. It also enhances the soil microbial activity and promotes sustainable nutrient cycling. This review provides an overview of different biostimulants and their influence on soil nutrient availability, crop nutrient transporters of nitrogen, phosphorus, sulfate, and iron.