Abstract
Tobacco (Nicotiana tabacum) mutants with 40 to 50% more catalase activity than wild type show O(2)-resistant photosynthesis under conditions of high photorespiration. More than 90% of the population of mutant plants of an M(7) and M(8) generation had enhanced catalase activity, and nearly 40% had activities >3 standard deviations above the mean of wild type. Superoxide dismutase activity was the same in mutant and wild-type leaves. The greater photosynthetic rate of mutant leaves previously observed in the laboratory was confirmed with field-grown plants that showed significantly higher rates (8%) than wild type during 8 days of measurements during a 19-day period of active growth. The tip region of expanding mutant leaves had higher catalase activity than the base of the lamina, and photosynthesis was O(2) resistant in 42% O(2) in the tip compared with the base, thus further supporting the hypothesis that there is a biochemical linkage between these traits. Plants grown in high light (270 micromole photons per square meter per second) had greater catalase activity and an activity ratio of mutant to wild type of 1.45 compared with 1.22 for those grown in low light (130 micromole photons per square meter per second). After acclimation for 3 weeks, plants transferred from low to high light showed increasing activities, and after 5 days the activity ratio of mutant to wild type was the same as in plants acclimated in higher light. The role of enhanced catalase activity in reducing photorespiratory CO(2) is discussed.
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Claims 12
Claim · model-written summary
The tobacco catalase mutant shows O2-resistant photosynthesis under high photorespiration, unlike wild type.
- Taxon
- Tobacco (Nicotiana tabacum)
Nicotiana tabacume1 - Material
- mutantse1
- Treatment
- high photorespiratione1
- Outcome
- O(2)-resistant photosynthesise1
- Comparator
- wild typee1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Tobacco (Nicotiana tabacum) mutants with 40 to 50% more catalase activity than wild type show O(2)-resistant photosynthesis under conditions of high photorespiration”
Claim · model-written summary
Tobacco mutants have 40 to 50% more catalase activity than wild type.
- Taxon
- Tobacco (Nicotiana tabacum)Nicotiana tabacume1
- Outcome
- catalase activitye1
- Direction
- moree1
- Value
- 40 to 50%e1
- Comparator
- wild typee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Tobacco (Nicotiana tabacum) mutants with 40 to 50% more catalase activity than wild type show O(2)-resistant photosynthesis under conditions of high photorespiration”
Claim · model-written summary
More than 90% of mutant plants in the M7 and M8 generations had enhanced catalase activity.
- Taxon
- Tobacco (Nicotiana tabacum)Nicotiana tabacume1
- Outcome
- enhanced catalase activitye2
- Value
- More than 90%e2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Tobacco (Nicotiana tabacum) mutants with 40 to 50% more catalase activity than wild type show O(2)-resistant photosynthesis under conditions of high photorespiration”
e2“More than 90% of the population of mutant plants of an M(7) and M(8) generation had enhanced catalase activity”
Claim · model-written summary
Nearly 40% of mutant plants had catalase activities more than 3 standard deviations above the wild-type mean.
- Taxon
- Tobacco (Nicotiana tabacum)Nicotiana tabacume1
- Outcome
- activitiese3
- Value
- nearly 40%e3
- Qualifier
- >3 standard deviations above the mean of wild typee3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Tobacco (Nicotiana tabacum) mutants with 40 to 50% more catalase activity than wild type show O(2)-resistant photosynthesis under conditions of high photorespiration”
e3“nearly 40% had activities >3 standard deviations above the mean of wild type”
Claim · model-written summary
Superoxide dismutase activity was the same in the mutant and wild type.
- Taxon
- Tobacco (Nicotiana tabacum)Nicotiana tabacume1
- Treatment
- mutante4
- Outcome
- Superoxide dismutase activitye4
- Direction
- the samee4
- Comparator
- wild-type leavese4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Tobacco (Nicotiana tabacum) mutants with 40 to 50% more catalase activity than wild type show O(2)-resistant photosynthesis under conditions of high photorespiration”
e4“Superoxide dismutase activity was the same in mutant and wild-type leaves”
Claim · model-written summary
Field-grown mutant plants had a significantly higher photosynthetic rate than wild type.
- Taxon
- Tobacco (Nicotiana tabacum)Nicotiana tabacume1
- Treatment
- field-grown plantse5
- Outcome
- photosynthetic ratee5
- Direction
- significantly highere5
- Value
- 8%e5
- Comparator
- wild typee5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Tobacco (Nicotiana tabacum) mutants with 40 to 50% more catalase activity than wild type show O(2)-resistant photosynthesis under conditions of high photorespiration”
e5“The greater photosynthetic rate of mutant leaves previously observed in the laboratory was confirmed with field-grown plants that showed significantly higher rates (8%) than wild type during 8 days of measurements”
Claim · model-written summary
The tip region of expanding mutant leaves had higher catalase activity than the base of the lamina.
- Taxon
- Tobacco (Nicotiana tabacum)Nicotiana tabacume1
- Organ / stage
- tip regione6
- Treatment
- expanding mutant leavese6
- Outcome
- catalase activitye6
- Direction
- highere6
- Comparator
- the base of the laminae6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Tobacco (Nicotiana tabacum) mutants with 40 to 50% more catalase activity than wild type show O(2)-resistant photosynthesis under conditions of high photorespiration”
e6“The tip region of expanding mutant leaves had higher catalase activity than the base of the lamina”
Claim · model-written summary
Photosynthesis in the tip of mutant leaves was O2 resistant at 42% O2, compared with the base.
- Taxon
- Tobacco (Nicotiana tabacum)Nicotiana tabacume1
- Organ / stage
- tipe7
- Treatment
- 42% O(2)e7
- Outcome
- photosynthesise7
- Comparator
- basee7
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Tobacco (Nicotiana tabacum) mutants with 40 to 50% more catalase activity than wild type show O(2)-resistant photosynthesis under conditions of high photorespiration”
e7“photosynthesis was O(2) resistant in 42% O(2) in the tip compared with the base”
Claim · model-written summary
Plants grown in high light had greater catalase activity than plants grown in low light.
- Taxon
- Tobacco (Nicotiana tabacum)Nicotiana tabacume1
- Treatment
- high light (270 micromole photons per square meter per second)e2
- Outcome
- catalase activitye2
- Direction
- greatere2
- Comparator
- low lighte2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Tobacco (Nicotiana tabacum) mutants with 40 to 50% more catalase activity than wild type show O(2)-resistant photosynthesis under conditions of high photorespiration”
e2“Plants grown in high light (270 micromole photons per square meter per second) had greater catalase activity and an activity ratio of mutant to wild type of 1.45 compared with 1.22 for those grown in low light”
Claim · model-written summary
The mutant-to-wild-type catalase activity ratio was 1.45 in high light compared with 1.22 in low light.
- Taxon
- Tobacco (Nicotiana tabacum)Nicotiana tabacume1
- Treatment
- high lighte2
- Outcome
- activity ratio of mutant to wild typee2
- Direction
- higherinferrede2
- Value
- 1.45 compared with 1.22e2
- Comparator
- low lighte2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Tobacco (Nicotiana tabacum) mutants with 40 to 50% more catalase activity than wild type show O(2)-resistant photosynthesis under conditions of high photorespiration”
e2“Plants grown in high light (270 micromole photons per square meter per second) had greater catalase activity and an activity ratio of mutant to wild type of 1.45 compared with 1.22 for those grown in low light”
Claim · model-written summary
After transfer from low to high light, the mutant-to-wild-type activity ratio became the same as in plants acclimated in higher light after 5 days.
- Taxon
- Tobacco (Nicotiana tabacum)Nicotiana tabacume1
- Treatment
- plants transferred from low to high lighte2
- Outcome
- activity ratio of mutant to wild typee2
- Direction
- the samee2
- Comparator
- plants acclimated in higher lighte2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Tobacco (Nicotiana tabacum) mutants with 40 to 50% more catalase activity than wild type show O(2)-resistant photosynthesis under conditions of high photorespiration”
e2“After acclimation for 3 weeks, plants transferred from low to high light showed increasing activities, and after 5 days the activity ratio of mutant to wild type was the same as in plants acclimated in higher light”
Claim · model-written summary
Plants transferred from low to high light showed increasing catalase activities after acclimation.
- Taxon
- Tobacco (Nicotiana tabacum)Nicotiana tabacume1
- Treatment
- plants transferred from low to high lighte2
- Outcome
- activitiese2
- Direction
- increasinge2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Tobacco (Nicotiana tabacum) mutants with 40 to 50% more catalase activity than wild type show O(2)-resistant photosynthesis under conditions of high photorespiration”
e2“After acclimation for 3 weeks, plants transferred from low to high light showed increasing activities, and after 5 days the activity ratio of mutant to wild type was the same as in plants acclimated in higher light”
The same questions in other papers
light · physiology: antioxidant enzymes · Nicotiana tabacum (tobacco)Positive and negative results
4 papers in the same direction as this paper · 1 reporting no difference from an alternative
- no effect
- 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.