Luteoviruses are economically important plant viruses, infecting almost all cereals throughout the world. Idiosyncrasies related to this virus group may be a strategic consequence of viral genome compression. However, many fundamental questions have yet to be resolved. This review summarizes selected findings covering molecular aspects of pathogenesis relating to plant-infecting RNA viruses in general, and luteoviruses in specific. These studies enhance our understanding of the replication structures and the virus infection pathways.