Abstract
The effects of reduced SBPase activity on growth and development were examined in a set of transgenic tobacco plants produced using an antisense construct driven by the ribulose bisphosphate carboxylase, small subunit promoter. Photosynthetic carbon assimilation rates and carbohydrate levels in source leaves were decreased in the antisense plants. Growth rate and total shoot biomass were reduced in the SBPase antisense plants, even in plants where SBPase activity was reduced by only 25%. Floral biomass also decreased in response to reductions in SBPase activity and the onset of flowering was delayed by 5-10 d. This is the first demonstration of a link between reproductive biomass and reductions in Calvin cycle enzyme activity using antisense plants. Furthermore, unexpected changes in the growth and development of the antisense plants were evident. Small reductions in SBPase activity (above 50% wild type) resulted in shorter plants with only a small decrease in stem biomass and specific leaf area. In contrast, plants with larger reductions in SBPase activity had an increase in specific leaf area and attained heights similar to that of the wild-type plants but with a much reduced stem biomass, largely due to a decrease in xylem tissue. This bi-modal response of growth to reductions in SBPase activity has similarities to changes in leaf and stem anatomy and morphology that accompany light acclimation.
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Claims 13
Claim · model-written summary
Photosynthetic carbon assimilation rates were decreased in the antisense plants
- Taxon
- tobacco
Nicotiana tabacumt0 - Treatment
- antisense plantse1
- Outcome
- Photosynthetic carbon assimilation ratese1
- Direction
- decreasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“transgenic tobacco plants”
e1“Photosynthetic carbon assimilation rates and carbohydrate levels in source leaves were decreased in the antisense plants”
Claim · model-written summary
Carbohydrate levels in source leaves were decreased in the antisense plants
- Taxon
- tobaccoNicotiana tabacumt0
- Organ / stage
- source leavese1
- Treatment
- antisense plantse1
- Outcome
- carbohydrate levelse1
- Direction
- decreasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“transgenic tobacco plants”
e1“Photosynthetic carbon assimilation rates and carbohydrate levels in source leaves were decreased in the antisense plants”
Claim · model-written summary
Growth rate and total shoot biomass were reduced in SBPase antisense plants even when SBPase activity was reduced by only 25%
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- SBPase antisense plantse2
- Outcome
- Growth rate and total shoot biomasse2
- Direction
- reducede2
- Qualifier
- even in plants where SBPase activity was reduced by only 25%e2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“transgenic tobacco plants”
e2“Growth rate and total shoot biomass were reduced in the SBPase antisense plants, even in plants where SBPase activity was reduced by only 25%”
Claim · model-written summary
Floral biomass decreased in response to reduced SBPase activity
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- reductions in SBPase activitye3
- Outcome
- Floral biomasse3
- Direction
- decreasede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“transgenic tobacco plants”
e3“Floral biomass also decreased in response to reductions in SBPase activity”
Claim · model-written summary
Onset of flowering was delayed by 5-10 d in plants with reduced SBPase activity
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- reductions in SBPase activitye3
- Outcome
- onset of floweringe4
- Direction
- delayede4
- Value
- 5-10 de4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“transgenic tobacco plants”
e3“Floral biomass also decreased in response to reductions in SBPase activity”
e4“the onset of flowering was delayed by 5-10 d”
Claim · model-written summary
Reproductive biomass is linked to reductions in Calvin cycle enzyme activity in antisense plants
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- reductions in Calvin cycle enzyme activitye5
- Outcome
- reproductive biomasse5
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“transgenic tobacco plants”
e5“This is the first demonstration of a link between reproductive biomass and reductions in Calvin cycle enzyme activity using antisense plants”
Claim · model-written summary
Plants with small reductions in SBPase activity (above 50% of wild type) were shorter
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- Small reductions in SBPase activity (above 50% wild type)e6
- Outcome
- shorter plantse6
- Direction
- shortere6
- Comparator
- wild typee6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“transgenic tobacco plants”
e6“Small reductions in SBPase activity (above 50% wild type) resulted in shorter plants with only a small decrease in stem biomass and specific leaf area”
Claim · model-written summary
Small reductions in SBPase activity caused only a small decrease in stem biomass and specific leaf area
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- Small reductions in SBPase activity (above 50% wild type)e6
- Outcome
- stem biomass and specific leaf areae6
- Direction
- small decreasee6
- Comparator
- wild typee6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“transgenic tobacco plants”
e6“Small reductions in SBPase activity (above 50% wild type) resulted in shorter plants with only a small decrease in stem biomass and specific leaf area”
Claim · model-written summary
Larger reductions in SBPase activity increased specific leaf area
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- larger reductions in SBPase activitye7
- Outcome
- specific leaf areae7
- Direction
- an increasee7
- Comparator
- wild-type plantse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“transgenic tobacco plants”
e7“In contrast, plants with larger reductions in SBPase activity had an increase in specific leaf area and attained heights similar to that of the wild-type plants but with a much reduced stem biomass, largely due to a decrease in xylem tissue”
Claim · model-written summary
Larger reductions in SBPase activity gave plant heights similar to wild type
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- larger reductions in SBPase activitye7
- Outcome
- heightse7
- Direction
- similare7
- Comparator
- wild-type plantse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“transgenic tobacco plants”
e7“In contrast, plants with larger reductions in SBPase activity had an increase in specific leaf area and attained heights similar to that of the wild-type plants but with a much reduced stem biomass, largely due to a decrease in xylem tissue”
Claim · model-written summary
Larger reductions in SBPase activity gave much reduced stem biomass
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- larger reductions in SBPase activitye7
- Outcome
- stem biomasse7
- Direction
- much reducede7
- Comparator
- wild-type plantse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“transgenic tobacco plants”
e7“In contrast, plants with larger reductions in SBPase activity had an increase in specific leaf area and attained heights similar to that of the wild-type plants but with a much reduced stem biomass, largely due to a decrease in xylem tissue”
Claim · model-written summary
Reduced stem biomass in plants with larger reductions in SBPase activity is largely due to decreased xylem tissue
- Taxon
- tobaccoNicotiana tabacumt0
- Outcome
- stem biomasse7
- Qualifier
- a decrease in xylem tissuee7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“transgenic tobacco plants”
e7“In contrast, plants with larger reductions in SBPase activity had an increase in specific leaf area and attained heights similar to that of the wild-type plants but with a much reduced stem biomass, largely due to a decrease in xylem tissue”
Claim · model-written summary
Antisense plants showed unexpected changes in growth and development
- Taxon
- tobaccoNicotiana tabacumt0
- Outcome
- changes in the growth and developmente2
- Qualifier
- unexpectede2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“transgenic tobacco plants”
e2“Furthermore, unexpected changes in the growth and development of the antisense plants were evident”
The same questions in other papers
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See all 10 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.