Abstract
Potato (Solanum tuberosum L.) plants transformed with sense and antisense constructs of a cDNA encoding the potato hexokinase 1 (StHK1) exhibited altered enzyme activities and expression of StHK1 mRNA. Measurements of the maximum catalytic activity of hexokinase revealed a 22-fold variation in leaves (from 22% of the wild-type activity in antisense transformants to 485% activity in sense transformants) and a 7-fold variation in developing tubers (from 32% of the wild-type activity in antisense transformants to 222% activity in sense transformants). Despite the wide range of hexokinase activities, no change was found in the fresh weight yield, starch, sugar, or metabolite levels of transgenic tubers. However, there was a 3-fold increase in the starch content of leaves from the antisense transformants after the dark period. Starch accumulation at the end of the night period was correlated with a 2-fold increase of glucose and a decrease of sucrose content. These results provide strong support for the hypothesis that glucose is a primary product of transitory starch degradation and is the sugar that is exported to the cytosol at night to support sucrose biosynthesis.
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Claims 9
Claim · model-written summary
Sense and antisense StHK1 transformants changed enzyme activity and transcript expression.
- Taxon
- Potato (Solanum tuberosum L.)
Solanum tuberosume0 - Treatment
- sense and antisense constructse0
- Gene
- StHK1e0
- Outcome
- enzyme activities and expression of StHK1 mRNAe0
- Direction
- alterede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Potato (Solanum tuberosum L.) plants transformed with sense and antisense constructs of a cDNA encoding the potato hexokinase 1 (StHK1) exhibited altered enzyme activities and expression of StHK1 mRNA.”
Claim · model-written summary
Leaf hexokinase activity ranged from 22% in antisense plants to 485% in sense plants relative to wild type.
- Taxon
- PotatoSolanum tuberosumt0
- Organ / stage
- leavese0
- Gene
- hexokinasee1
- Outcome
- maximum catalytic activity of hexokinasee1
- Direction
- variatione0
- Value
- 22-folde0
- Qualifier
- from 22% of the wild-type activity in antisense transformants to 485% activity in sense transformantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a 22-fold variation in leaves (from 22% of the wild-type activity in antisense transformants to 485% activity in sense transformants)”
t0“Potato”
e1“maximum catalytic activity of hexokinase”
Claim · model-written summary
Developing tuber hexokinase activity ranged from 32% in antisense plants to 222% in sense plants.
- Taxon
- PotatoSolanum tuberosumt0
- Organ / stage
- developing tuberse0
- Outcome
- hexokinase activitiese1
- Direction
- variatione0
- Value
- 7-folde0
- Qualifier
- from 32% of the wild-type activity in antisense transformants to 222% activity in sense transformantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a 7-fold variation in developing tubers (from 32% of the wild-type activity in antisense transformants to 222% activity in sense transformants)”
t0“Potato”
e1“Despite the wide range of hexokinase activities”
Claim · model-written summary
Transgenic tubers had no change in fresh weight yield.
- Taxon
- PotatoSolanum tuberosumt0
- Material
- transgenic tuberse0
- Outcome
- fresh weight yielde0
- Direction
- no changee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Potato”
e0“no change was found in the fresh weight yield, starch, sugar, or metabolite levels of transgenic tubers”
Claim · model-written summary
Transgenic tubers had no change in starch, sugar, or metabolite levels.
- Taxon
- PotatoSolanum tuberosumt0
- Material
- transgenic tuberse0
- Outcome
- starch, sugar, or metabolite levelse0
- Direction
- no changee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Potato”
e0“no change was found in the fresh weight yield, starch, sugar, or metabolite levels of transgenic tubers”
Claim · model-written summary
Antisense leaves had threefold higher starch content after darkness.
- Taxon
- PotatoSolanum tuberosumt0
- Organ / stage
- leavese0
- Treatment
- antisense transformantse0
- Outcome
- starch contente0
- Direction
- increasee0
- Value
- 3-folde0
- Qualifier
- after the dark periode0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Potato”
e0“a 3-fold increase in the starch content of leaves from the antisense transformants after the dark period”
Claim · model-written summary
Night starch accumulation correlated with a twofold glucose increase.
- Taxon
- PotatoSolanum tuberosumt0
- Compound
- glucosee0
- Outcome
- Starch accumulatione0
- Direction
- increasee0
- Value
- 2-folde0
- Qualifier
- at the end of the night periode0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Potato”
e0“Starch accumulation at the end of the night period was correlated with a 2-fold increase of glucose”
Claim · model-written summary
Night starch accumulation correlated with reduced sucrose content.
- Taxon
- PotatoSolanum tuberosumt0
- Compound
- sucrosee0
- Outcome
- Starch accumulatione0
- Direction
- decreasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Potato”
e0“Starch accumulation at the end of the night period was correlated with a 2-fold increase of glucose and a decrease of sucrose content”
Claim · model-written summary
The authors support glucose as the primary product of transient starch breakdown and night export sugar.
- Taxon
- PotatoSolanum tuberosumt0
- Compound
- glucosee0
- Outcome
- primary product of transitory starch degradatione0
- Qualifier
- exported to the cytosol at night to support sucrose biosynthesise0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Potato”
e0“glucose is a primary product of transitory starch degradation and is the sugar that is exported to the cytosol at night to support sucrose biosynthesis”
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See all 14 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.