Grapevine red blotch-associated virus is Present in Free-Living Vitis spp. Proximal to Cultivated Grapevines

Abstract

Red blotch is an emerging disease of grapevine associated with grapevine red blotch-associated virus (GRBaV). The virus spreads with infected planting stocks but no vector of epidemiological significance has been conclusively identified. A vineyard block of red-blotch-affected Vitis vinifera 'Cabernet franc' clone 214 was observed in California, with a clustering of infected, symptomatic vines focused along one edge of the field proximal to a riparian habitat with free-living Vitis spp. No genetic heterogeneity was observed in a 587-nucleotide region of the GRBaV genome in a population of 44 Cabernet franc clone 214 isolates. By contrast, genetic differences were observed in isolates from other cultivars and clones growing in adjacent blocks. GRBaV was confirmed infecting four free-living vines, two of which were shown to be V. californica × V. vinifera hybrids. The genomes of three free-living GRBaV vine isolates and seven from V. vinifera cultivars were compared; free-living vine isolates were shown to be more similar to each other and a 'Merlot' isolate than to the other cultivated vine isolates. The finding that GRBaV is present in free-living Vitis spp. indicates the virus can be spread by natural (nonhuman-mediated) means, and we hypothesize that in-field spread of GRBaV is occurring.

High-Throughput Sequencing and the Viromic Study of Grapevine Leaves: From the Detection of Grapevine-Infecting Viruses to the Description of a New Environmental Tymovirales Member

“…While most plant viruses have probably co-existed with their hosts before domestication, others likely represent novel pathogen-host interactions. Many grapevine-infecting viruses or viroids have been detected in all grapevine-growing region within the last decade (Al Rwahnih et al, 2009, 2012, 2016; Navarro et al, 2009; Coetzee et al, 2010; Zhang et al, 2011, 2014; Giampetruzzi et al, 2012; Poojari et al, 2013; Beuve et al, 2015; Jo et al, 2017a,b; Silva et al, 2017; Blouin et al, 2018a,b; Candresse et al, 2018; Diaz-Lara et al, 2018), which is probably due to a combination of many factors such as: (i) the vegetative multiplication and international trade, (ii) newer and wider areas of cultivation associated with additional and different viral reservoir pool leading to potential spill-over (Perry et al, 2016), (iii) climate change with latent virus being awaken (Jones, 2015), (iv) a greater number of research being completed on such a high-profit/valuable crop, and (v) the use of the newest deep-sequencing technology (HTS, high-throughput sequencing) serving as a very sensitive diagnostic tool (Adams et al, 2009; Candresse et al, 2014). …”

Grapevine red blotch virus: Absence in Swiss Vineyards and Analysis of Potential Detrimental Effect on Viticultural Performance

“…Furthermore, GRBV is observed on native and wild Vitis spp. collected around infected vineyards, indicating that this virus is not only spread by viticultural practices (i.e., vegetative propagation) but also naturally (Bahder et al 2016b;Perry et al 2016). Although significant advances have been made in understanding GRBV since its discovery in 2012, the epidemiology is poorly understood.…”

Fangorn Forest (F2): a machine learning approach to classify genes and genera in the family Geminiviridae

“…The number of scientific studies on the family Geminiviridae has significantly increased in the last ten years ( geminivirus.org :8080/geminivirusdw/statistics.jsp). The broad diversity of species, the large number of complete sequences, and the discovery of new geminiviruses have increased the complexity in determining the nomenclature and providing the taxonomic classification of geminiviruses [ 3 , 30 – 32 , 61 – 63 ]. Another issue in the family Geminiviridae concerns some particular genes in some species of the genus Mastrevirus , post-transcriptional changes may occur in primary gene transcripts, such as for MSV, whose genome holds gene C1:C2 [ 49 ].…”