Abstract
In previous studies with tomato ( Lycopersicon esculentum L.) exposed to a low level (3.7 kJ m –2) of UV-C (λ: 254 nm) radiation, which is defined as a beneficial level, we report a delay in fruit ripening by at least 1 week for treated fruit. In the present study, we investigate the changes in the activities of different enzymes involved in defense mechanisms, such as guaiacol peroxidase, ascorbate peroxidase, catalase, superoxide dismutase, ascorbate oxidase, lipoxygenase and phenylalanine ammonia lyase in tomato fruit in response to a beneficial level of UV-C. The irradiation leads to an increase in the guaiacol peroxidase and ascorbate peroxidase activities, whereas catalase activity remains similar to the control. The activities of superoxide dismutase and ascorbate oxidase were significantly reduced after UV-C exposure. In UV-C-treated fruit, an increase of lipoxygenase and phenylalanine ammonia lyase activities occurred within the first 5 d, followed by a second period in which these activities were below those of the control. Our study suggests that the level of UV-C used induced a rapid but moderate accumulation of photooxidation products, to which plants react by stimulating their defence mechanisms against oxidation. This activation may explain the delay observed in ripening and senescence of irradiated tomato fruit.
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Claims 8
Claim · model-written summary
Low UV-C delayed tomato fruit ripening by at least one week.
- Taxon
- tomato
Solanum lycopersicumt0 - Treatment
- UV-Ce1
- Outcome
- fruit ripeninge1
- Direction
- delaye1
- Value
- at least 1 weeke1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“tomato ( Lycopersicon esculentum )”
e1“UV-C (λ: 254 nm) radiation, which is defined as a beneficial level, we report a delay in fruit ripening by at least 1 week for treated fruit”
Claim · model-written summary
UV-C increased guaiacol peroxidase and ascorbate peroxidase activities in tomato fruit.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- irradiatione2
- Outcome
- guaiacol peroxidase and ascorbate peroxidase activitiese2
- Direction
- increasee2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“tomato ( Lycopersicon esculentum )”
e2“The irradiation leads to an increase in the guaiacol peroxidase and ascorbate peroxidase activities”
Claim · model-written summary
Catalase activity remained similar to the control after irradiation.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- irradiatione2
- Outcome
- catalase activitye3
- Direction
- remains similare3
- Comparator
- controle3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“tomato ( Lycopersicon esculentum )”
e3“catalase activity remains similar to the control”
e2“The irradiation leads to an increase in the guaiacol peroxidase and ascorbate peroxidase activities”
Claim · model-written summary
UV-C significantly reduced superoxide dismutase and ascorbate oxidase activities.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- UV-C exposuree4
- Outcome
- activities of superoxide dismutase and ascorbate oxidasee4
- Direction
- reducede4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“tomato ( Lycopersicon esculentum )”
e4“The activities of superoxide dismutase and ascorbate oxidase were significantly reduced after UV-C exposure”
Claim · model-written summary
UV-C increased lipoxygenase and phenylalanine ammonia lyase activities during the first five days.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- UV-C-treatede5
- Outcome
- lipoxygenase and phenylalanine ammonia lyase activitiese5
- Direction
- increasee5
- Qualifier
- within the first 5 de5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“tomato ( Lycopersicon esculentum )”
e5“In UV-C-treated fruit, an increase of lipoxygenase and phenylalanine ammonia lyase activities occurred within the first 5 d”
Claim · model-written summary
Later, those enzyme activities fell below control levels.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- UV-C-treatede5
- Outcome
- these activitiese6
- Direction
- belowe6
- Comparator
- controle6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“tomato ( Lycopersicon esculentum )”
e6“followed by a second period in which these activities were below those of the control”
e5“In UV-C-treated fruit, an increase of lipoxygenase and phenylalanine ammonia lyase activities occurred within the first 5 d”
Claim · model-written summary
The authors infer that this UV-C level induced rapid, moderate accumulation of photooxidation products.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- UV-Ce7
- Outcome
- accumulation of photooxidation productse7
- Qualifier
- rapid but moderatee7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“tomato ( Lycopersicon esculentum )”
e7“the level of UV-C used induced a rapid but moderate accumulation of photooxidation products”
Claim · model-written summary
The authors propose that UV-C stimulated defenses against oxidation, potentially explaining delayed fruit ripening and senescence.
- Taxon
- tomatoSolanum lycopersicumt0
- Outcome
- delay observed in ripening and senescencee0
- Qualifier
- This activatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“tomato ( Lycopersicon esculentum )”
e0“This activation may explain the delay observed in ripening and senescence of irradiated tomato fruit”
The same questions in other papers
radiation · physiology: antioxidant enzymes · Solanum lycopersicum (tomato)Results agree
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- positive
- positive
- positive
1 paper more in this group
See all 5 papers →uv · physiology: antioxidant enzymes · Solanum lycopersicum (tomato)Results agree
5 papers in the same direction as this paper
- positive
- positive
- positive
2 papers more in this group
See all 6 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.