Characterization of a Novel Emaravirus Affecting Ash Species (Fraxinus spp.) in Europe

We identified a novel virus in diseased European ash (Fraxinus excelsior) and manna (F. ornus) trees exhibiting chlorotic ringspots, mottle leaf deformation such as curling shoestring symptoms. High-throughput sequencing (HTS, Illumina RNASeq) of total RNA isolated from material combination with RT-PCR-based amplification techniques Sanger determined five complete genome segments, each encoding single open reading frame. Sequence analyses RNA1–RNA5 revealed organization typical for emaraviruses, i.e., (i) conserved complementary terminal 5′ 3′ termini segment (ii) proteins showing significant homologies to the RNA-dependent polymerase (RdRP) encoded by RNA1, glycoprotein precursor (GPP) RNA2, viral nucleocapsid protein (N, RNA3), movement (MP, RNA4), 26 kDA (P26, RNA5) highly similar unknown function other emaraviruses. Furthermore, we spherical particles (double-membrane bodies, DMB) different sizes (70–80 nm diameter) which are emaraviruses exclusively virus-infected tissue deformation. comparison phylogenetic confirmed new member genus Emaravirus. established species-specific RT-PCR detection protocol could associate observed disease symptoms infection emaravirus F. excelsior ornus. Therefore, propose name shoestring-associated (ASaV). Investigation ASaV-infected sample originating locations Switzerland, Germany, Italy Sweden provided wide geographical distribution affected species. To our knowledge, this is first confirmation an affecting tree species leaves Europe.