Abstract
Soybean mosaic virus (SMV), a member of the Potyviridae family, is one of the most economically significant viruses affecting soybean (Glycine max (L.) Merr.) crops globally. This review comprehensively examines the virological and genetic characteristics of SMV, its transmission mechanisms, host specificity, genomic structure, and the functional roles of its proteins, as well as the immune response of the host plant. The roles of viral proteins such as HC-Pro and CP, along with the DAG, KLSC, and PTK motifs, are critically analyzed for their contribution to aphid- and seed-mediated transmission. Genetic diversity and inter-strain differences in SMV isolates from the USA, China, Korea, and other regions, including evidence of recombination and mutation-driven evolution, are presented. Host resistance genes such as Rsv1, Rsv3, and Rsv4 mediate hypersensitive and extreme resistance, with molecular determinants including P3, HC-Pro, and CI proteins. This paper also analyzes the plant's defensive mechanisms, including salicylic acid, jasmonate, and ethylene signalling pathways, reactive oxygen species (ROS) generation, and the expression of pathogenesis-related (PR) genes. These findings provide crucial insights for breeding SMV-resistant soybean cultivars and developing integrated control strategies. The study insights form a foundation for the development of SMV-resistant soybean cultivars, the implementation of marker-assisted selection (MAS) strategies, and the design of integrated disease management programs tailored to the molecular biology of the virus and its interaction with the soybean host.