Abstract
Summary: Of seven plant viruses tested, all except tobacco mosaic showed the phenomenon of photoreactivation, i.e. plants exposed to visible light after inoculation with preparations partially inactivated by ultraviolet radiation produced more local lesions than plants kept in darkness. Five strains of tobacco mosaic virus, which differed widely in their pathogenicity and other properties, were tested, but none showed the phenomenon. Of the six viruses that did, potato showed it much the most strongly, tomato bushy stunt and a tobacco necrosis virus the least; cabbage black ringspot, cucumber mosaic and tobacco ringspot were intermediate. Photoreactivation does not occur immediately after plants are inoculated. With irradiated preparations of potato virus X, most particles need about 30 min. to reach the state in which their ability to infect is affected by light; once in this state, exposure to daylight for 15 min. gives almost complete photoreactivation. Some irradiated particles respond to light of 80 f.c., but others need brighter light; no additional response occurs when light intensity is increased above 600 f.c. The sensitive state of potato virus X persists for about 1 hr. in plants kept in darkness, after which the particles seem to be permanently inactivated. With antibodies and enzymes, a constant amount of absorbed energy decreases the activity of a unit weight by a given fraction. This rule does not apply to plant viruses, which lose infectivity with less absorbed energy than the rule predicts. If viruses are more sensitive because they contain nucleic acid, their sensitivity is not a direct function of their content of nucleic acid. Potato virus X has the same nucleic acid content as strains of tobacco mosaic virus, but is inactivated by less absorbed energy and individual strains of tobacco mosaic virus also differ by factors of two in the amount of radiation needed to decrease their infectivity by a given fraction.
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Claims 13
Claim · model-written summary
For six of seven plant viruses tested (all except tobacco mosaic), plants exposed to visible light after inoculation with UV-partially-inactivated preparations produced more local lesions than plants kept in darkness (photoreactivation).
Verbatim
e0“Of seven plant viruses tested, all except tobacco mosaic showed the phenomenon of photoreactivation, i.e. plants exposed to visible light after inoculation with preparations partially inactivated by ultraviolet radiation produced more local lesions than plants kept in darkness”
Claim · model-written summary
Five strains of tobacco mosaic virus, differing widely in pathogenicity and other properties, none showed photoreactivation.
- Interactor
- tobacco mosaic virus
Tobacco mosaic viruse0pathogen - Outcome
- none showed the phenomenone0
Not reportedTaxon
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Five strains of tobacco mosaic virus, which differed widely in their pathogenicity and other properties, were tested, but none showed the phenomenon”
Claim · model-written summary
Among the six viruses showing photoreactivation, potato virus showed it most strongly, tomato bushy stunt and a tobacco necrosis virus the least, and cabbage black ringspot, cucumber mosaic and tobacco ringspot were intermediate.
- Outcome
- showed it much the most stronglye0
Not reportedTaxon
Verbatim
e0“Of the six viruses that did, potato showed it much the most strongly, tomato bushy stunt and a tobacco necrosis virus the least; cabbage black ringspot, cucumber mosaic and tobacco ringspot were intermediate”
Claim · model-written summary
Photoreactivation does not occur immediately after plants are inoculated.
- Taxon
- plantsViridiplantaee0
- Outcome
- Photoreactivation does not occur immediatelye0
Verbatim
e0“Photoreactivation does not occur immediately after plants are inoculated”
Claim · model-written summary
For irradiated potato virus X preparations, most particles need about 30 min to reach the state in which their infectivity is affected by light.
- Taxon
- potato virus XPotato virus Xe0
- Interactor
- potato virus XPotato virus Xe0pathogen
- Outcome
- most particles need about 30 min. to reach the statee0
- Value
- about 30 min.e0
Verbatim
e0“With irradiated preparations of potato virus X, most particles need about 30 min. to reach the state in which their ability to infect is affected by light”
Claim · model-written summary
Once in the light-sensitive state, exposure to daylight for 15 min gives almost complete photoreactivation of potato virus X.
- Taxon
- potato virus XPotato virus Xe1
- Treatment
- exposure to daylight for 15 min.e0
- Outcome
- photoreactivatione0
- Direction
- almost completee0
Not reportedComparator
Verbatim
e0“once in this state, exposure to daylight for 15 min. gives almost complete photoreactivation”
e1“With irradiated preparations of potato virus X, most particles need about 30 min. to reach the state in which their ability to infect is affected by light”
Claim · model-written summary
Some irradiated potato virus X particles respond to light of 80 f.c., while others need brighter light.
Not reportedTaxon
Verbatim
e0“Some irradiated particles respond to light of 80 f.c., but others need brighter light”
Claim · model-written summary
No additional photoreactivation response occurs when light intensity is increased above 600 f.c.
Not reportedTaxon
Verbatim
e0“no additional response occurs when light intensity is increased above 600 f.c.”
Claim · model-written summary
The light-sensitive state of potato virus X persists for about 1 hour in plants kept in darkness, after which particles appear permanently inactivated.
- Taxon
- potato virus XPotato virus Xe0
- Outcome
- The sensitive statee0
- Value
- about 1 hr.e0
- Setting
- plants kept in darknesse0
Verbatim
e0“The sensitive state of potato virus X persists for about 1 hr. in plants kept in darkness”
Claim · model-written summary
Plant viruses lose infectivity with less absorbed energy than the antibody/enzyme rule predicts.
Verbatim
e0“This rule does not apply to plant viruses, which lose infectivity with less absorbed energy than the rule predicts”
Claim · model-written summary
Virus sensitivity to inactivation is not a direct function of nucleic acid content.
Not reportedDirection
Verbatim
e0“If viruses are more sensitive because they contain nucleic acid, their sensitivity is not a direct function of their content of nucleic acid”
Claim · model-written summary
Potato virus X has the same nucleic acid content as tobacco mosaic virus strains but is inactivated by less absorbed energy.
- Taxon
- Potato virus XPotato virus Xe0
- Interactor
- tobacco mosaic virusTobacco mosaic viruse0pathogen
- Outcome
- inactivated by less absorbed energye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Potato virus X has the same nucleic acid content as strains of tobacco mosaic virus, but is inactivated by less absorbed energy”
Claim · model-written summary
Individual tobacco mosaic virus strains differ by factors of two in the radiation needed to decrease infectivity by a given fraction.
- Taxon
- tobacco mosaic virusTobacco mosaic viruse0
- Outcome
- the amount of radiation needed to decrease their infectivitye0
- Value
- factors of twoe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“individual strains of tobacco mosaic virus also differ by factors of two in the amount of radiation needed to decrease their infectivity by a given fraction”