Lectin-centered signaling networks orchestrate plant immunity, stress adaptation, and development

Plant lectins are structurally diverse non-catalytic carbohydrate-binding proteins, some of which contribute directly to defense against herbivores and pathogens. However, emerging evidence suggests that lectins function far beyond passive defense factors and instead constitute a multilayered signaling system coordinating environmental perception, immunity, stress adaptation and development throughout the plant life cycle. Recent studies reveal that lectins perceive diverse endogenous and exogenous cues, including glycoconjugates, peptides and damage-associated molecules, and integrate these signals into conserved downstream signaling networks. In parallel, intracellular lectins contribute to pathogen restriction, physiological homeostasis and developmental regulation through direct modulation of cellular signaling pathways. Together, these findings position lectins as central components of a broader plant glyco-signaling framework linking extracellular information with adaptive physiological outputs. In this Review, we synthesize recent advances in lectin-mediated signaling across plant immunity, abiotic stress adaptation and developmental regulation, discuss how post-translational modifications expand lectin signaling plasticity, and highlight emerging translational opportunities in sustainable agriculture, including immune engineering, programmable receptor design and targeted biomolecule delivery. Finally, we propose that lectin-mediated signaling represents an underappreciated regulatory layer underlying plant environmental adaptation and outline key challenges for harnessing lectins in next-generation crop improvement.