Molecular characterization of a novel mycovirus in Alternaria alternata manifesting two-sided effects: Down-regulation of host growth and up-regulation of host plant pathogenicity.
Virology
; 519: 23-32, 2018 06.
Article
de En
| MEDLINE
| ID: mdl-29631173
ABSTRACT
A double-stranded RNA (dsRNA) mycovirus was detected in a strain of Alternaria alternata showing impaired growth phenotypes. The A. alternata strain is the Japanese pear pathotype, which produces a host-specific AK-toxin. Sequence analysis of the viral genome dsRNAs revealed that this mycovirus consists of five dsRNAs and is evolutionarily related to members of the family Chrysoviridae; the virus was named Alternaria alternata chrysovirus 1 (AaCV1). AaCV1-ORF2 protein accumulated in dsRNA-high-titer sub-isolates with severely impaired phenotypes; heterologous AaCV1-ORF2 overexpression in Saccharomyces cerevisiae caused growth inhibition. In contrast to this yeast growth inhibition phenomenon, the dsRNA-high-titer isolates displayed enhanced pathogenicity against Japanese pear plants, in accordance with a 13-fold increase in AK-toxin level in one such isolate. These findings indicated that AaCV1 is a novel mycovirus that exhibits two contrasting effects, impairing growth of the host fungus while rendering the host 'hypervirulent' to the plant.
Mots clés
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Pyrus
/
Alternaria
/
Virus fongiques
Langue:
En
Journal:
Virology
Année:
2018
Type de document:
Article
Pays d'affiliation:
Japon