RRC ID 30980
Author Ikeda Y, Shimura H, Kitahara R, Masuta C, Ezawa T.
Title A novel virus-like double-stranded RNA in an obligate biotroph arbuscular mycorrhizal fungus: a hidden player in mycorrhizal symbiosis.
Journal Mol Plant Microbe Interact
Abstract Arbuscular mycorrhizal (AM) fungi form mutualistic associations with most land plants and enhance phosphorus uptake of the host plants. Fungal viruses (mycoviruses) that possess a double-stranded RNA (dsRNA) genome often affect plant-fungal interactions via altering phenotypic expression of their host fungi. The present study demonstrates, for the first time, the presence of dsRNAs, which are highly likely to be mycoviruses, in AM fungi. dsRNA was extracted from mycelia of Glomus sp. strain RF1, purified, and subjected to electrophoresis. The fungus was found to harbor various dsRNA segments that differed in size. Among them, a 4.5-kbp segment was termed Glomus sp. strain RF1 virus-like medium dsRNA (GRF1V-M) and characterized in detail. The GRF1V-M genome segment was 4,557 nucleotides in length and encoded RNA-dependent RNA polymerase and a structural protein. GRF1V-M was phylogenetically distinct and could not be assigned to known genera of mycovirus. The GRF1V-M-free culture line of Glomus sp. strain RF1, which was raised by single-spore isolation, produced twofold greater number of spores and promoted plant growth more efficiently than the GRF1V-M-positive lines. These observations suggest that mycoviruses in AM fungi, at least some of them, have evolved under unique selection pressures and are a biologically active component in the symbiosis.
Volume 25(7)
Pages 1005-12
Published 2012-7-1
DOI 10.1094/MPMI-11-11-0288
PMID 22414436
MeSH Amino Acid Motifs Amino Acid Sequence Base Sequence Genome, Viral / genetics* Glomeromycota / physiology Glomeromycota / virology* Molecular Sequence Data Mycorrhizae / physiology Mycorrhizae / virology* Phenotype Phylogeny Plant Roots / growth & development Plant Roots / microbiology Plant Roots / virology Plant Shoots / growth & development Poaceae / growth & development Poaceae / microbiology Poaceae / virology RNA Viruses / classification* RNA Viruses / genetics RNA Viruses / isolation & purification RNA, Double-Stranded / chemistry RNA, Double-Stranded / genetics RNA, Double-Stranded / isolation & purification* RNA, Viral / chemistry RNA, Viral / genetics RNA, Viral / isolation & purification RNA-Dependent RNA Polymerase / genetics Reverse Transcriptase Polymerase Chain Reaction Sequence Alignment Sequence Analysis, RNA Symbiosis* Viral Proteins / genetics
IF 3.696
Times Cited 23
Lotus / Glycine Miyakojima MG-20