First report of grapevine hammerhead viroid - like RNA (GHVd) in grapevine in Greece

摘要

In September 2017, leafroll disease-like symptoms were observed in a commercial vineyard cv. Syrah in the island of Crete. A symptomatic vine (Syr1) was selected and transferred to the Institute of Olive Tree, Subtropical Crops and Viticulture for virus analysis. Total RNAwas extracted from phloem scrapings of the affected vine using Plant RNA/DNA Purification Kit (Norgen Biotek Corporation, Canada) and subjected to high-throughput sequencing (HTS) on an Illumina HiSeq2500 platform yielding ~40 million 100 bp paired-end reads. After a first read subtraction against the Vitis vinifera genome the de novo assembly of the remaining unmapped reads produced 1333 contigs. Ten of the generated sequences were of viral/viroid origin and revealed co-infection by grapevine leafroll-associated virus 3 (GLRaV-3), grapevine rupestris stem pitting-associated virus (GRSPaV), grapevine yellow speckle viroid - 1 (GYSVd-1) and hop stunt viroid (HSVd). Moreover, a partial 281 nt sequence of grapevine hammerhead viroid-like RNA (GHVd) was retrieved from the data. GHVd is a recently identified single-stranded circular RNA molecule that is poorly characterized.