VIEW ARTICLE

Etiology

Physicochemical Properties of Bean Rugose Mosaic Virus. Pilar Ramírez, Centro de Investigación en Biología Celular y Molecular, Universidad de Costa Rica, Ciudad Universitaria 2060, Costa Rica; Ana Mercedes Espinoza(2), Ana Lucía Fuentes(3), and Pedro León(4). (2)(3)Centro de Investigación en Biología Celular y Molecular, Universidad de Costa Rica, Ciudad Universitaria 2060, Costa Rica; (4)Research scientist for Consejo de Investigaciones Científicas y Tecnológicas de Costa Rica (CONICIT). Phytopathology 77:1317-1321. Accepted for publication 25 February 1987. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/Phyto-77-1317.

Susceptible bean cultivars infected with bean rugose mosaic virus (BRMV) yield three sedimentation components in isopycnic and zonal gradients. The top component contains empty shells; the middle and bottom components, both required for infection, contain distinct RNA molecules of 1.4 and 2.1 × 10⁶, respectively. One large (41 K) and two small polypeptides (21 and 23 K) are found in all components. The 21 K polypeptide appears to be derived by proteolytic cleavage from the 23 K polypeptide. In addition, each RNA contains a genome-bound peptide (VPg) on the 5’ end and a poly-A tail on the 3’ end of the molecule. All of these properties clearly support the inclusion of BRMV in the comovirus group, as previously proposed on the basis of immunoreactivity.