Overlapping but distinct viromes observed in a population of cultivated and wild grapevines

Authors: HU, RONGBIN - University Of Tennessee; PINTO, NAYMA - University Of Tennessee; SOLTANI, NOUROLAH - University Of Tennessee; HENSLEY, DARRELL - University Of Tennessee; PERRY, KEITH - Cornell University; Domier, Leslie; HAJIMORAD, M - University Of Tennessee

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/5/2021
Publication Date: N/A
Citation: N/A

Interpretive Summary: Grape production has been expending rapidly in the central United States. As grapevines are planted in new geographic regions, they are exposed to new pathogens and pests. Wild and volunteer grapevines endemic in central US have the potential to serve as reservoirs for grapevine-infecting viruses and viroids. To understand the potential of viruses and viroids to move between cultivated and wild grapevines, the viruses infecting 42 wild and 85 cultivated grapevines in Tennessee were compared. Eighteen viruses and two viroids were detected among the two populations, 10 of which were common to the two populations. Analysis of the genetic structure of the common viruses showed that viruses present in the two grapevine populations were distinct suggesting that there was limited virus movement between the two populations. Consequently, most virus infections in cultivated grapevine likely are spread through management practices rather than from wild reservoirs. These results will be of interest to scientists studying the epidemiology of grapevine-infecting viruses and grape producers interested in managing virus infections in vineyards.

Technical Abstract: Viromes of a population of 42 wild grapevines (Vitis spp.) were compared to a population of 85 cultivated grapevines collected in Tennessee, USA by high throughput sequencing of transcriptomes. Analyses of the sequence data from the populations revealed the sequences from 18 viruses and two viroids. Of these, sequences of two viruses, alfalfa mosaic virus and a novel enamovirus, were identified only among transcriptomes derived from wild grapevines. On the other hand, sequences from four viruses, grapevine associated tymo-like virus, grapevine leafroll-associated virus 3, grapevine red blotch virus and grapevine virus H were identified only from cultivated grapevines. The sequences of 10 viruses (grapevine-associated caulimovirus, grapevine-associated nanovirus 1, grapevine fleck virus, grapevine leafroll-associated virus 2, grapevine rupestris stem pitting-associated virus, grapevine Syrah virus 1, grapevine vein-clearing virus, grapevine virus B, grapevine virus E, tobacco ringspot virus, and tomato ringspot virus) were detected in both grapevine populations. Additionally, full-length genomes of hop stunt viroids and grapevine yellow speckle viroid 1 were present in both populations of grapevines. The presence of the sequences from most of the above viruses and both viroids were verified independently in the original samples by reverse-transcriptase polymerase chain reaction. Collectively, this study represents the first non-biased survey of viruses and viroids in cultivated and wild grapevines within a defined geographic region. The observation that many of the viruses in the two grapevine populations were distinct suggests that there was limited virus movement between the two populations.