Novel Viroid‐Like RNAs Naturally Infect a Filamentous Fungus (Adv. Sci. 3/2023)

Viroid-Like RNAs In article number 2204308, Wenxing Xu, Kaili Dong, and co-workers characterize a novel class of viroid-like RNAs naturally infecting a filamentous fungus Botryosphaeria dothidea isolated from apple and termed as mycoviroids. These mycoviroids replicate autonomously in the nucleus via a rolling-circle mechanism following a symmetric pathway, can apparently modulate specific biological traits of the host fungus, and represent a new class of acellular entities endowed with regulatory functions, and novel epigenomic carriers of biological information. This is the first report of infectious viroid-like RNAs (or exogenous small circular RNAs) in a life kingdom (fungi) other than plants.