Root exudates are critical signaling molecules in belowground plant–plant interactions, regulating physiological and ecological responses in adjacent plants through kinship recognition and self-/non-self-discrimination systems. This review systematically synthesizes the compositional diversity of root exudates, with particular emphasis on elucidating the ecological foundations of plant recognition modalities (kin recognition, allelopathy, plant self-/non-self-identification, and growth regulation). The analyses demonstrate that exudate composition is dynamically modulated by plant species identity, rhizosphere microbial communities, and environmental stressors, with signaling functions mediated through both physical signal transduction and chemical signal decoding. This chemical communication system not only drives species-specific interaction strategies but redefines the theoretical frameworks of plant community assembly by establishing causal linkages between molecular signaling events and ecological outcomes.
Meng et al. (Sat,) studied this question.