Novel mitoviruses in Rhizoctonia solani AG-3PT infecting potato

Subha Das; Richard E Falloon; Alison Stewart; Andrew R Pitman

doi:10.1016/j.funbio.2015.11.002

Novel mitoviruses in Rhizoctonia solani AG-3PT infecting potato

Fungal Biol. 2016 Mar;120(3):338-50. doi: 10.1016/j.funbio.2015.11.002. Epub 2015 Dec 1.

Authors

Subha Das¹, Richard E Falloon², Alison Stewart³, Andrew R Pitman⁴

Affiliations

¹ Bio-Protection Research Centre, PO Box 85084, Lincoln University 7647, New Zealand; The New Zealand Institute for Plant & Food Research Limited, PB 4704, Christchurch, New Zealand. Electronic address: subhadas1981@gmail.com.
² Bio-Protection Research Centre, PO Box 85084, Lincoln University 7647, New Zealand; The New Zealand Institute for Plant & Food Research Limited, PB 4704, Christchurch, New Zealand. Electronic address: richard.falloon@plantandfood.co.nz.
³ Bio-Protection Research Centre, PO Box 85084, Lincoln University 7647, New Zealand; Scion, Te Papa Tipu Innovation Park, 49 Sala Street, Private Bag 3020, Rotorua 3046, New Zealand. Electronic address: alison.stewart@scionresearch.com.
⁴ Bio-Protection Research Centre, PO Box 85084, Lincoln University 7647, New Zealand; The New Zealand Institute for Plant & Food Research Limited, PB 4704, Christchurch, New Zealand. Electronic address: andrew.pitman@plantandfood.co.nz.

PMID: 26895862
DOI: 10.1016/j.funbio.2015.11.002

Abstract

Double-stranded RNA (dsRNA) elements are ubiquitous in Rhizoctonia solani. Total dsRNA was randomly amplified from a R. solani isolate (RS002) belonging to anastomosis group-3PT (AG-3PT), associated with black scurf in potato. Assembly of resulting cDNA sequences identified a nearly complete genome of a novel virus related to the genus Mitovirus (family Narnaviridae), herein named Rhizoctonia mitovirus 1 RS002 (RMV-1-RS002). The 2797 nucleotide partial genome of RMV-1-RS002 is A-U rich (59.06 %), and can be folded into stable stem-loop structures at 5' and 3' ends. Universal and mold mitochondrial codon usages revealed a large open reading frame in the genome, putatively encoding an 826 amino acid polypeptide, which has conserved motifs for mitoviral RNA-dependent RNA polymerase. The full length putative polypeptide shared 25.6 % sequence identity with the corresponding region of Tuber excavatum mitovirus (TeMV). The partial genome of a second mitovirus (proposed name Rhizoctonia mitovirus 2 RS002 (RMV-2-RS002)) was also amplified from RS002. A nearly identical copy of RMV-1-RS002 was detected in two additional AG-3PT isolates. These data indicate that multiple mitoviruses can exist in a single isolate of R. solani AG-3PT, and that mitoviruses such as RMV-1-RS002 are probably widespread in this pathogen. The roles of mitoviruses in the biology of R. solani AG-3PT remain unknown.

Keywords: Double-stranded RNA (dsRNA); Hypovirulence; Mycovirus; Narnaviridae; RNA-dependent RNA polymerase (RdRp).

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Genome, Viral
Molecular Sequence Data
Nucleic Acid Conformation
Open Reading Frames
Phylogeny
Plant Diseases / microbiology*
RNA Viruses / classification
RNA Viruses / genetics
RNA Viruses / isolation & purification*
RNA, Viral / chemistry
RNA, Viral / genetics
RNA-Dependent RNA Polymerase / genetics
Rhizoctonia / isolation & purification*
Rhizoctonia / virology*
Sequence Analysis, DNA
Sequence Homology, Amino Acid
Solanum tuberosum / microbiology*

Substances

RNA, Viral
RNA-Dependent RNA Polymerase