A plant virus evolved by acquiring multiple nonconserved genes to extend its host range

• DOI: 10.1073/pnas.1113227108
• Publication Date: 2011-10-11T05:31:58Z
• Authors: Satyanarayana Tat...; Cecile J. Robertson; Stephen M. Garnsey; William O. Dawson
• Keywords: Citrus tristeza virus; Closterovirus; ORFS

Viruses have evolved as combinations of genes whose products interact with cellular components to produce progeny virus throughout the plants. Some viral genes, particularly those that are involved in replication and assembly, tend be relatively conserved, whereas other for interactions specific host movement counter host–defense systems less conserved. Closteroviridae encode 1–5 nonconserved ORFs. Citrus tristeza (CTV), a Closterovirus , possesses p33, p18, p13 expendable systemic infection two laboratory hosts, macrophylla Mexican lime. In this study, we show extended range CTV requires these genes. The p33 gene was required systemically infect sour orange lemon trees, either or p18 sufficient grapefruit trees calamondin Thus, three full CTV, but different were hosts. Remarkably, some citrus hybrids. These findings suggest acquired multiple (p33, p13) and, result, gained ability thus extending its during course evolution. results greatly extend complexity known virus–plant interactions.