Authors: Arvind Varsani Philippe Roumagnac Marc Fuchs Jesús NavasCastillo Enrique Moriones Ali Idris Rob W Briddon Rafael RiveraBustamante F Murilo Zerbini Darren P Martin
Publish Date: 2017/02/17
Volume: 162, Issue: 6, Pages: 1819-1831
Abstract
Geminiviruses are plantinfecting singlestranded DNA viruses that occur in most parts of the world Currently there are seven genera within the family Geminiviridae Becurtovirus Begomovirus Curtovirus Eragrovirus Mastrevirus Topocuvirus and Turncurtovirus The rate of discovery of new geminiviruses has increased significantly over the last decade as a result of new molecular tools and approaches rollingcircle amplification and deep sequencing that allow for highthroughput workflows Here we report the establishment of two new genera Capulavirus with four new species Alfalfa leaf curl virus Euphorbia caputmedusae latent virus French bean severe leaf curl virus and Plantago lanceolata latent virus and Grablovirus with one new species Grapevine red blotch virus The aphid species Aphis craccivora has been shown to be a vector for Alfalfa leaf curl virus and the treehopper species Spissistilus festinus is the likely vector of Grapevine red blotch virus In addition two highly divergent groups of viruses found infecting citrus and mulberry plants have been assigned to the new species Citrus chlorotic dwarf associated virus and Mulberry mosaic dwarf associated virus respectively These species have been left unassigned to a genus by the ICTV because their particle morphology and insect vectors are unknownThe family Geminiviridae includes plantinfecting viruses with circular ssDNA genomes that are encapsidated in virions comprised of 22 pentameric capsomeres arranged in a ~18 to 30nm twinned icosahedral or geminate configuration 7 41 Geminiviruses have a nearglobal distribution and infect both monocotyledonous and dicotyledonous plants Geminiviruses are often responsible for serious yield losses in economically important crops including tomato maize cotton chickpea and cassava 25 Symptoms of geminivirus infections can include foliar crinkling curling yellowing stunting mosaic and/or striationsThe Geminiviridae Study Group of the International Committee on Taxonomy of Viruses ICTV has provided a series of guidelines for the classification of viruses within the seven currently recognised genera of the family Becurtovirus Begomovirus Curtovirus Eragrovirus Mastrevirus Topocuvirus and Turncurtovirus The criteria include host range insect vector genome organisation and genomewide pairwise sequence identities 1 11 12 26 38 39Furthermore recently a single virus isolated from an apple tree in China tentatively referred to as apple geminivirus AGmV 20 and 13 virus isolates from grapevine in Hungary Israel Japan and South Korea tentatively referred to as grapevine geminivirus A GGVA sharing 97 pairwise identity have been discovered 2 These have distinctly geminiviruslike genome organisations and are more closely related to members of some established geminivirus species than they are to citrus chlorotic dwarf associated virus CCDaV and mulberry mosaic dwarf associated virus MMCaV The taxonomic assignment of AGmV and GGVA still needs to be discussed by the ICTV
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