First report of barley virus G infecting corn in Greece

Authors: GAVRILI, VASSILIA - Aristotle University Of Thessaloniki; LOTOS, LEONIDAS - Aristotle University Of Thessaloniki; Mollov, Dimitre; Grinstead, Sam; TSIALTAS, IOANNIS - Aristotle University Of Thessaloniki; KATIS, NIKOLAOS - Aristotle University Of Thessaloniki; MALIOGKA, VARVARA - Aristotle University Of Thessaloniki

Submitted to: Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/5/2021
Publication Date: 7/19/2021
Citation: Gavrili, V., Lotos, L., Mollov, D.S., Grinstead, S.C., Tsialtas, I., Katis, N., Maliogka, V. 2021. First report of barley virus G infecting corn in Greece. Plant Disease. https://doi.org/10.1007/s42161-021-00903-4.
DOI: https://doi.org/10.1007/s42161-021-00903-4

Interpretive Summary: Corn is an important crop used for food and feed worldwide. In this report, we investigated five corn samples in Greece that exhibited virus like symptoms using high-throughput sequencing. All five samples were infected with sugarcane mosaic virus, and one sample was infected with barley virus G (BVG). BVG, which was first reported from South Korea, has not previously been reported in Greece or southeastern Europe. The complete genome of this BVG isolate was determined and primers for PCR detection were designed. This work expands the reported distribution range of BVG and provides information that will be useful for virus detection.

Technical Abstract: Corn (Zea mays) is one of the most important spring cash crops in Greece, where it is grown for silage. In June 2019, corn plants exhibiting foliar virus-like symptoms of mosaic, interveinal yellowing and yellow streak were observed in a field trial (40o32’22’’N, 23o00’45’’E, 30 m) in Thermi, Greece. To identify the causal agent(s) of the disease, five samples were subjected to high-throughput sequencing (HTS). The HTS cDNA libraries generated between 18.7 and 25.7 million reads. The de novo contigs were assembled with SPAdes (Nurk et al., 2013) and subjected to a local BLASTn similarity search. Sugarcane mosaic virus (SCMV, genus Potyvirus) was detected in all samples, maize dwarf mosaic virus (MDMV, genus Potyvirus) in one sample, and barley virus G (BVG, a tentative member of family Luteoviridae, genus Polerovirus) in one different sample. SCMV and MDMV have been previously reported in Greece (Panayotou, 1980, Ivanovic, D., et al., 1995). The BVG contigs were assembled into a 5,530 nt long scaffold, covering almost the complete genome, which was ~98% identical to BVG isolates Gimje and Uiseong (accession numbers KT962089.1 and LC259081.1, respectively). To confirm the BVG infection, a primer pair was designed based on the de novo contig sequence. Primers BVG3646up (5'-AAC ACT TCA GGA GGA TCT GGA-3') and BVG4247down (5'-AAC TCG GAA TTC TTG CGT GA-3'), which amplify a coat protein/movement protein/P5 segment of 602 nt, were used in a one-step RT-PCR assay. Sanger sequencing (GenBank accession number MT672307), confirmed the BVG infection, as the nucleotide identity between the amplicon and the de novo contig was 100%, and the BLASTn search of NCBI indicated the isolate from Greece was almost identical (99.47%) to the South Korean BVG isolate Uiseong. This is, to our knowledge, the first report of BVG in Greece. BVG was initially reported in Gimje, South Korea in 2016 (Zhao, et.al., 2016). Outside Korea, BVG has only been confirmed in Australia, Hungary and The Netherlands (Kumar et al., 2018, Nancarrow et al., 2019, Pasztor et al., 2020). Further studies are needed to determine the epidemiology of the virus and its association with cereal crop diseases in Greece.