Drought mitigation in plants through root exudate-mediated rhizosphere interactions: Opportunities for future research

Abstract

Drought is among the most significant environmental factors that frequently limits the growth and productivity of terrestrial plants, making them susceptible to various diseases and resulting in the death of many species each year. Because the plants could not relocate to avoid environmental stresses (i.e., drought, cold temperatures, and high salinity), they developed specific adaptive mechanisms at the root-soil interface to cope with these stresses, especially drought. For instance, under drought conditions, plants change the composition of root exudates by increasing the concentrations of abscisic acid (ABA). This hormone is transported through the xylem transport system to plant leaves, signalling the leaf stomata to regulate stomatal activity. It reduces water loss in plants and enhances their resistance to drought conditions. This review examines the role of soil-root-microbe interactions under drought stress and highlights how this interaction influences nutrient cycling, osmotic pressure adjustment, signalling pathways, and microbial recruitment to enhance plant resilience under drought stress. Furthermore, the mechanisms by which root exudates enhance plant resilience through nitrogen and phosphorus cycling, detoxification of aluminium toxicity, and regulation of stomatal activity are discussed. Understanding these processes and mechanisms provides new insights into developing sustainable forest and agricultural management practices that enhance plant productivity under drought conditions by increasing their resilience in a changing environment.