The predominant lengths of tubular particles produced by the CAM isolate of tobacco rattle virus (520 and 1950 Å long) and of the PRN isolate (650 to 800 and 1900 Å long) were separated by density gradient centrifugation. On their own, short particles of each isolate neither caused lesions in leaves nor multiplied detectably. Long particles of either isolate caused lesions which contained virus nucleic acid, but virus particles were not found in extracts of the lesions; when the lesions were thawed after 3 days storage at -15°, the extracts had little or no infectivity. When short particles were mixed with long particles of the same isolate, the number of lesions produced by the long particles was not affected, but a proportion of these lesions then contained tubular virus particles of both lengths, and also infective material resistant to freezing and thawing. This proportion increased from zero to unity with increasing concentration of short particles in the inoculum; it also increased with increasing susceptibility to infection of the plants used as the of the lesions, but seemed unaffected by the concentration of long particles in the inoculum. With isolate CAM, the lesions containing stable virus particles could be distinguished by their smaller necrotic centres. When short particles were ultraviolet-irradiated, their ability to interact with long ones was abolished, but the interaction was not prevented by removing virus protein from both long and short particles by phenol treatment. No interaction was detected between particles of the two different isolates, which are distantly related serologically, or between their nucleic acids. Each isolate of tobacco rattle virus seems to be a system of two or more pieces of infective nucleic acid interacting specifically in a symbiotic manner.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error