I. Zabalgogeazcoa et al., DOUBLE-STRANDED-RNA AND VIRUS-LIKE PARTICLES IN THE GRASS ENDOPHYTE EPICHLOE-FESTUCAE, Mycological research, 102, 1998, pp. 914-918
Two double-stranded ribonucleic acid (dsRNA) elements were detected in
an isolate of the clavicipitaceous grass endophyte Epichloe festucae
obtained from an asymptomatic Festuca rubra plant. No dsRNA was detect
ed in three other isolates of E. festucae. The size of the two dsRNA e
lements isolated from mycelium was of 5.2 and 3.2 kbp. Hybridization e
xperiments with a cDNA probe complementary to the 5.2 kbp dsRNA showed
that there was no sequence similarity between the dsRNA elements. Iso
metric viruslike particles of about 50 nm in diameter were observed by
electron microscopy in sucrose-gradient purified virus preparations f
rom the isolate containing dsRNA. The 5.2 kbp dsRNA element was presen
t in the partially purified virus preparations, suggesting that this e
lement is encapsidated. There was no difference with respect to growth
rate or colony morphology between the dsRNA containing and dsRNA-free
isolates. The presence of dsRNA and virus-like particles suggests the
presence of a mycovirus in the Vit5 strain of E. festucae.