What does virusoid mean?
Virusoid is a specialist term for a small infectious agent made of RNA without the protein coat, or capsid, normally associated with a conventional virus. Such agents are especially associated with diseases of plants. In older scientific writing, virusoid was often used broadly for infectious naked RNA, particularly the agents now called viroids. More precise contemporary usage distinguishes the two categories: a viroid is infectious naked RNA that does not encode proteins, while a virusoid may encode one or more proteins. This distinction places virusoids at the boundary between viruses and viroids, combining some virus-like characteristics with the absence of a complete viral coat. The word is mainly encountered in plant pathology, virology, and molecular biology. It is rarely appropriate in general prose unless a discussion concerns infectious nucleic acids or plant disease. Its historical formation from virus and the suffix -oid also reflects its original characterization as a virus-like form.
nounA small infectious agent consisting of naked RNA without a protein coat, typically associated with disease in plants. In modern specialized usage, virusoids are distinguished from viroids by encoding one or more proteins.
- A small infectious agent consisting of naked RNA without a protein coat, particularly one associated with plant disease.
- A subviral infectious agent that encodes proteins and is therefore distinguished from a viroid in more specialized usage.
"The plant showed the characteristic symptoms of a virusoid infection."
"The plant showed the characteristic symptoms of a virusoid infection."
"Researchers determined that the naked circular RNA behaved as a virusoid because it encoded a protein."
The regular plural used when referring to more than one virusoid or to a class of virusoids.
"Several virusoids have been identified in diseased plants."
A virusoid can infect without wearing the familiar protein coat of a conventional virus.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of virusoid
Virusoid was formed in English by combining virus with the suffix -oid, a form of the Greek suffix -eidēs, associated with form or resemblance. Its semantic background is the Latin virus, meaning poison or a slimy liquid, from which English also derives words such as viral, virology, and virulent. The closely related term viroid was developed later for infectious naked RNAs that do not encode proteins.
Related word forms
How virusoid is actually used
Virusoid is primarily a specialist botanical or virological term. Its use varies among older and newer sources: some treat it as broadly synonymous with viroid, while finer technical distinctions separate agents that encode proteins from those that do not.
Easily confused with virusoid
A viroid is infectious naked RNA that does not encode proteins, whereas a virusoid, in the narrower modern distinction, encodes at least one protein; older sources sometimes use the terms interchangeably.