Antiviral activity in plants of a mycoviral double-strained RNA from Trichothecium roseum.

Hexagonal virus-like particles (VLPs) measuring 45 nm across were detected in mycelial extracts from Trichothecium roseum Himachal strain, the source fungus for the production of T-poly (Trichothecium polysaccharide), a known inhibitor of plant viruses. VLPs were found to contain double-stranded RNA (ds RNA) and the purified ds RNA was capable of inhibiting tobacco mosaic virus infection in Nicotiana glutinosa plants. Active preparations of T-poly were found to contain traces of ds RNA, probably of mycoviral origin.