Seed transmission of potyviruses: A threat to crop health

Abstract

Plant introductions, including the movement of seeds across international borders, significantly contribute to the emergence of viral pathogens, which account for approximately half of all emerging plant diseases. Among plant virus families, the Potyviridae stand out as the largest and most economically impactful. The potyvirus genus with 201 species widespread across various crops, causes substantial crop losses globally. These viruses are primarily transmitted by aphids in a nonpersistent manner, with some also capable of transmission through seeds. Global food security is significantly impacted by the crucial part that seed transmission plays in the epidemiology and spread of different plant viruses. With transmission rates varying greatly between viruses and host plants, over 231 viruses were discovered to be capable of spreading through seeds, including 20 seed-transmitted potyviruses. The seed transmission efficiency of potyviruses such as maize dwarf mosaic virus (MDMV), cowpea aphid-borne mosaic virus (CABMV), and bean common mosaic virus (BCMV) ranges from 3% to 95%. Other notable viruses include soybean mosaic virus (SMV) (58% transmission) and pea seed-borne mosaic virus (PSbMV) (100% transmission). The diversity in seed transmission efficiency among viruses demonstrates the important role that seeds play in the propagation and dissemination of viral pathogens. In addition, seed transmission permits viruses to survive in unfavorable environments, promotes long-distance spread via international seed exchange, and acts as the main point of infection for viruses that have vertical transmission. The complex dynamics of seed transmission and the complex relationship between viruses and their host plants highlight the significance of strict phytosanitary measures in protecting global agriculture from the destructive effects of viruses transmitted through seeds. This review focuses on potyvirus seed transmission, with an emphasis on determining the significance of this mode and understanding the potential role of seed transmission in potyviruses.