Molecular characterization of a novel ssRNA ourmia-like virus from the rice blast fungus Magnaporthe oryzae
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In this study we characterize a novel positive and single stranded RNA (ssRNA) mycovirus isolated from the rice field isolate of Magnaporthe oryzae Guy11. The ssRNA contains a single open reading frame (ORF) of 2,373 nucleotides in length and encodes an RNA-dependent RNA polymerase (RdRp) closely related to ourmiaviruses (plant viruses) and ourmia-like mycoviruses. Accordingly, we name this virus Magnaporthe oryzae ourmia-like virus 1 (MOLV1). Although phylogenetic analysis suggests that MOLV1 is closely related to ourmia and ourmia-like viruses, it has some features never reported before within the Ourmiavirus genus. 3’ RLM-RACE (RNA ligase-mediated rapid amplification of cDNA ends) and extension poly(A) tests (ePAT) suggest that the MOLV1 genome contains a poly(A) tail whereas the three cytosine and the three guanine residues present in 5’ and 3’ untranslated regions (UTRs) of ourmia viruses are not observed in the MOLV1 sequence. The discovery of this novel viral genome supports the hypothesis that plant pathogenic fungi may have acquired this type of viruses from their host plants.
KeywordsPlant Virus Rice Blast Fungus Guanine Residue Fungal Host ssRNA Virus
A.S. is funded by the Spanish Research council (grant ref. BIO2014-53211-R), the EC (REA grant agreement n. 304039) and the Community of Madrid (grant ref. S2013/ABI-2734).
Compliance with ethical standards and conflict of interest
This paper is in compliance with ethical standards for research. The authors declare no conflicts of interest.
- 2.Andrew King EL, Michael J. Adams and Eric B. Carstens (2012) Virus taxonomy, 1st edn. Ninth report of the International Committee on Taxonomy of Viruses. Elsevier, p 1344Google Scholar
- 11.Hillman BI, Cai G (2013) The family Narnaviridae: simplest of RNA viruses, chapter 6. In: Said AG (ed) Advances in virus research. Academic Press, pp 149–176Google Scholar
- 23.Marzano S-YL, Nelson BD, Ajayi-Oyetunde O, Bradley CA, Hughes TJ, Hartman GL, Eastburn DM, Domier LL (2016) Identification of diverse mycoviruses through metatranscriptomics characterization of the viromes of five major fungal plant pathogens. J Virol 90:6846–6863. doi: 10.1128/JVI.00357-16 CrossRefPubMedPubMedCentralGoogle Scholar
- 27.Rastgou M, Habibi MK, Izadpanah K, Masenga V, Milne RG, Wolf YI, Koonin EV, Turina M (2009) Molecular characterization of the plant virus genus Ourmiavirus and evidence of inter-kingdom reassortment of viral genome segments as its possible route of origin. J Gen Virol 90:2525–2535CrossRefPubMedPubMedCentralGoogle Scholar