A New Ilarvirus Found in French Hydrangea

Abstract

In this study, a new virus was identified in French hydrangea plants, exhibiting chlorotic vein banding and necrotic ring spots on older leaves. The virus was mechanically transmitted to herbaceous hosts, in which it induced local and systemic or only local symptoms. The genome of the new virus was characterized and consisted of three RNA sequences that were 3422 (RNA 1), 2905 (RNA 2) and 2299 (RNA 3) nucleotides long, with five predicted open reading frames; RNA2 was bicistronic and contained conserved domains and motifs typical of ilarviruses. The phylogenetic analysis of the predicted proteins—p1, p2a, p3a and p3b—revealed its close relationship to recognized members of subgroup 2 within the genus Ilarvirus. Homologous antiserum was effective in the detection of the virus in plant extracts and no cross reactions with two other distinct members of subgroup 2 were observed. Overall, the biological features, phylogenetic relationships and serological data suggest that this virus is a new member of the genus, for which we propose the name hydrangea vein banding virus (HdVBV).

The Virome of Babaco (Vasconcellea × heilbornii) Expands to Include New Members of the Rhabdoviridae and Bromoviridae

“…Some plant rhabdoviruses have been reported either as non-pathogenic or able to cause mild symptoms in single infections [ 12 , 32 , 33 ], whereas ilarviruses have long been associated with an array of leaf or fruit symptoms, including mosaic, vein banding, ringspot, and necrosis, among others [ 34 , 35 , 36 , 37 ]. A particular symptom, commonly known as ‘necrotic shock’, caused by the ilarviruses blueberry shock virus (BlShV) and strawberry necrotic shock virus (SNSV), consists of severe leaf necrosis followed by defoliation [ 36 , 38 ].…”

“…It remains to be determined whether the symptomatology observed in the co-infected plant could be attributed to either BabIV-1, BabRV-1, their interaction with each other, with BabVQ, or with additional viruses not detected in this study. Some plant rhabdoviruses have been reported either as non-pathogenic or able to cause mild symptoms in single infections [12,32,33], whereas ilarviruses have long been associated with an array of leaf or fruit symptoms, including mosaic, vein banding, ringspot, and necrosis, among others [34][35][36][37]. A particular symptom, commonly known as 'necrotic shock', caused by the ilarviruses blueberry shock virus (BlShV) and strawberry necrotic shock virus (SNSV), consists of severe leaf necrosis followed by defoliation [36,38].…”

Hydrangea Diseases in Japan

“…Approximately 20 of these causal agents can also be found in Shimane Prefecture (Nagashima unpublished). At least 17 viruses, 2 phytoplasmas, 8 bacteria, 14 oomycetes, and 167 fungi were found on hydrangeas throughout the world (Baysal-Gurel et al 2016, Chen et al 2022, Cottyn et al 2021, Gardan & Dorkar 1985, Hilton 2000, Machado Caballero et al 2009, Menzel et al 2016, NARO Genebank 2022a, Parrella & Troiano 2022, Uddin et al 1996, USDA ARS 2022, Veerakone et al 2012. Therefore, Japan has approximately one-third of the world's recorded hydrangea diseases, including the local causal agents.…”

Metagenomic analysis reveals the presence of prunus virus I in diseased Clematis vitalba: first record of this virus in Italy

“…Based on the nucleotide sequences that were obtained, specific primers (Supplementary Table 1) were redesigned to amplify fragments of the 5'-upstream and 3'-downstream regions, corresponding to each segmented genome by 5' and 3'-RACE (rapid amplification of cDNA ends), as described by Parrella and Troiano (2022). Amplicons of the expected sizes were directly sequenced in both directions at Microsynth Seqlab GmbH (Göttingen, Germany).…”