plant viruses

[ROOSSINCK,MARILYN]

In article <3fcqj1$4efq at usenetp1.news.prodigy.com>, YAYV60A at prodigy.com (Ana-rene Bolton) writes...
>onenight at rain.org  wrote:
>>
>>Please excuse a layman's question, but is there an incedence in 
>virology
>>where a plant virus can be transmitted to an animal?
>>
>>I appreciate your patience and any reply would be appreciated.
>>
>>one night in the rain
>>onenight at rain.com
> 
>I'm a layman too, but I remember reading that animal viruses can have the 
>ability to cross-infect other species.  I don't know if that would hold 
>for plant viruses, but I can see no reason why not if the virus utilizes 
>a substance common to both plants and animals.  That does NOT mean 
>however, that the virus will be able to cause DISEASE in the cross-
>infected species, but it may also be possible for the virus to develop 
>the ability to cause disease in its new host.
> 
>Hope this helps.

Plant viruses are often transmitted by insects, and in a few cases they are
also replicated (ie they infect) their insect vector as well as the plant. 
There has not been any documented case of a plant virus infecting other
animals, but it is not impossible.  As for viruses developing the ability to
cause disease, that is somewhat unlikely--in general disease does not confer a
selective advantage to a virus, so it causes disease only as an accidental
perturbation of the normal functions of its host.  There are, of course, a few 
exceptions, such as the sneezing induced by rhinoviruses, that allows them to 
spread to new hosts very efficiently.  More often however disease is a
disadvantage to the virus, especially when it results in death of the host.

M. Roossinck
The S.R. Noble Foundation