Root exudation and rhizosphere biology involve the secretion of compounds by plant roots into the soil, which play critical roles in regulating microbial communities, defending against pests, and influencing plant interactions. Root exudates, including low- and high-molecular-weight compounds, are essential for soil microbial interactions, plant competition, and nutrient cycling. These exudates can act as chemical signals for symbiotic or pathogenic organisms, influencing the rhizosphere environment. Root exudation is a significant carbon cost for plants, yet the mechanisms controlling this process are still being studied. Root exudates include amino acids, organic acids, sugars, and secondary metabolites, which can promote beneficial symbioses, deter pathogens, and alter soil properties. The rhizosphere is a dynamic zone where roots interact with other roots, microbes, and insects, and these interactions are crucial for plant survival. Root-root communication can be positive or negative, with allelochemicals playing a role in plant competition. Root-microbe communication is vital for symbiotic relationships, such as mycorrhizal associations, and for defense against pathogens through the secretion of phytoalexins. Root-insect communication involves chemical signals that can deter herbivores, as seen in the case of oca roots secreting phototoxic alkaloids. Root exudates also influence soil structure and water retention, contributing to root-soil contact and soil stability. The cellular mechanisms of root exudation involve subcellular trafficking of metabolites, including the use of vesicles and ABC transporters for secretion. The spatial localization of root exudation varies along the root axis, with different sections exhibiting distinct metabolic activities. Understanding root exudation is crucial for improving plant fitness and discovering novel compounds in the rhizosphere.Root exudation and rhizosphere biology involve the secretion of compounds by plant roots into the soil, which play critical roles in regulating microbial communities, defending against pests, and influencing plant interactions. Root exudates, including low- and high-molecular-weight compounds, are essential for soil microbial interactions, plant competition, and nutrient cycling. These exudates can act as chemical signals for symbiotic or pathogenic organisms, influencing the rhizosphere environment. Root exudation is a significant carbon cost for plants, yet the mechanisms controlling this process are still being studied. Root exudates include amino acids, organic acids, sugars, and secondary metabolites, which can promote beneficial symbioses, deter pathogens, and alter soil properties. The rhizosphere is a dynamic zone where roots interact with other roots, microbes, and insects, and these interactions are crucial for plant survival. Root-root communication can be positive or negative, with allelochemicals playing a role in plant competition. Root-microbe communication is vital for symbiotic relationships, such as mycorrhizal associations, and for defense against pathogens through the secretion of phytoalexins. Root-insect communication involves chemical signals that can deter herbivores, as seen in the case of oca roots secreting phototoxic alkaloids. Root exudates also influence soil structure and water retention, contributing to root-soil contact and soil stability. The cellular mechanisms of root exudation involve subcellular trafficking of metabolites, including the use of vesicles and ABC transporters for secretion. The spatial localization of root exudation varies along the root axis, with different sections exhibiting distinct metabolic activities. Understanding root exudation is crucial for improving plant fitness and discovering novel compounds in the rhizosphere.