Biological and Molecular Characterization of Two Closely Related Arepaviruses and Their Antagonistic Interaction in .

Previously, our group characterized two closely related viruses from , areca palm necrotic ringspot virus (ANRSV) and areca palm necrotic spindle-spot virus (ANSSV). These two viruses share a distinct genomic organization of leader proteases and represent the only two species of the newly established genus of the family . The biological features of the two viruses are largely unknown. In this study, we investigated the pathological properties, functional compatibility of viral elements, and interspecies interactions in the model plant, . Using a newly obtained infectious clone of ANRSV, we showed that this virus induces more severe symptoms compared with ANSSV and that this is related to a rapid virus multiplication . A series of hybrid viruses were constructed the substitution of multiple elements in the ANRSV infectious clone with the counterparts of ANSSV. The replacement of either 5'-UTR-HCPro1-HCPro2 or CI effectively supported replication and systemic infection of ANRSV, whereas individual substitution of P3-7K, 9K-NIa, and NIb-CP-3'-UTR abolished viral infectivity. Finally, we demonstrated that ANRSV confers effective exclusion of ANSSV both in coinfection and super-infection assays. These results advance our understanding of fundamental aspects of these two distinct but closely related arepaviruses.