Advances in Genetic Transformation of Lotus corniculatus: Methodological Determinants, Applications and Future Priorities

Lotus corniculatus is a superior leguminous forage with multiple values including forage, ecological, ornamental and medicinal uses. It is also an ideal material for plant bioreactors. As a core technical approach, genetic transformation overcomes the constraints of traditional breeding and facilitates the targeted improvement in stress resistance and agronomic traits in this species. This review summarizes the research progress of the Agrobacterium-mediated genetic transformation of L. corniculatus, focusing on key procedures such as explant selection, strain selection, infection and co-cultivation regimes, basal medium composition, phytohormone regulation, as well as bacteria elimination and transformant screening strategies. We further elaborate on the applications of this transformation system in enhancing tolerance to abiotic stresses (salt, drought and heat), regulating quality-related traits, and developing plant-based vaccine bioreactors. Additionally, this paper critically discusses the major bottlenecks and challenges constraining existing genetic transformation systems in L. corniculatus, and evaluates the prospects for establishing high-efficiency and genetically stable transformation platforms. This review aims to provide theoretical foundations and technical references for germplasm innovation, molecular breeding and comprehensive utilization of L. corniculatus.