Multifunctional roles of the rice mannose-binding lectin OsMBL1 in biotic and abiotic stress responses

Abiotic and biotic stresses severely impair crop growth and productivity, posing substantial threats to global agricultural production. To cope with complex environmental challenges, plants have evolved sophisticated stress-adaptive mechanisms, including the inducible expression of multifunctional regulatory proteins and dynamic functional reprogramming. The rice mannose-binding lectin OsMBL1 has emerged as a critical regulator of both abiotic and biotic stress responses, serving as a valuable model for understanding the multifaceted biological functions of a single protein. Transcript expression analyses have demonstrated that OsMBL1 is significantly induced by salt, drought, cold, heat, phytohormones, and rice blast infection. Its dynamic subcellular localization patterns further provide a structural foundation for its versatile roles in diverse stress responses. Reverse genetic assays have verified that OsMBL1 positively modulates rice tolerance to salt, drought, and rice blast, while negatively regulating cold tolerance, making it a candidate molecular indicator for salt and drought stress research in rice. This review systematically summarizes the research advances and nomenclature evolution of OsMBL1 since 1990, highlighting its biological functions and underlying molecular regulatory mechanisms, particularly ubiquitination-dependent protein modulation. Collectively, this work reveals that OsMBL1 serves as a valuable paradigm for dissecting the multifunctional adaptive mechanisms of plant lectins in response to varied environmental stresses.