The Complex World of Emaraviruses—Challenges, Insights, and Prospects

• Published in: Forests Vol. 13; no. 11; p. 1868
• Main Authors: Rehanek, Marius, Karlin, David G., Bandte, Martina, Al Kubrusli, Rim, Nourinejhad Zarghani, Shaheen, Candresse, Thierry, Büttner, Carmen, von Bargen, Susanne
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.11.2022; MDPI
• Subjects: Blackberries; diagnosis; Disease; distribution; DNA-directed RNA polymerase; Economic impact; emaraviruses; Environmental aspects; Fimoviridae; Food quality; Forecasts and trends; forest trees; genome organization; Genomes; Glycoproteins; Homology; Host plants; Hygiene; Impact analysis; Infections; Life Sciences; Mechanical transmissions; Mites; Movement protein; Nucleocapsids; Pathogenicity; Pathogens; Phylogeny; Phytopathology and phytopharmacy; Plant breeding; Plant viruses; Prepolymers; Proteins; RNA polymerase; RNA viruses; RNA-directed RNA polymerase; Segments; Vectors; Vegetal Biology; Virology; Virus diseases of plants; Viruses; Woody plants; Germany; forest trees; transmission; phylogenetic relations; genome organization; Fimoviridae; diagnosis; symptomatology; distribution; emaraviruses; protein domains
• ISSN: 1999-4907; 1999-4907
• DOI: 10.3390/f13111868

Emaravirus (Order Bunyavirales; Family Fimoviridae) is a genus comprising over 20 emerging plant viruses with a worldwide distribution and economic impact. Emaraviruses infect a variety of host plants and have especially become prevalent in important long-living woody plants. These viruses are enveloped, with a segmented, single-stranded, negative-sense RNA genome and are transmitted by eriophyid mites or mechanical transmission. Emaraviruses have four core genome segments encoding an RNA-dependent RNA polymerase, a glycoprotein precursor, a nucleocapsid protein, and a movement protein. They also have additional genome segments, whose number varies widely. We report here that the proteins encoded by these segments form three main homology groups: a homolog of the sadwavirus Glu2 Pro glutamic protease; a protein involved in pathogenicity, which we named “ABC”; and a protein of unknown function, which we named “P55”. The distribution of these proteins parallels the emaravirus phylogeny and suggests, with other analyses, that emaraviruses should be split into at least two genera. Reliable diagnosis systems are urgently needed to detect emaraviruses, assess their economic and ecological importance, and take appropriate measures to prevent their spread (such as routine testing, hygiene measures, and control of mite vectors). Additional research needs include understanding the function of emaravirus proteins, breeding resistant plants, and clarifying transmission modes.