Abstract
Polyols are important metabolites that often function as carbon and energy sources and/or osmoprotective solutes in some plants. In grapevine, and in the grape berry in particular, the molecular aspects of polyol transport and metabolism and their physiological relevance are virtually unknown to date. Here, the biochemical function of a grapevine fruit mesocarp polyol transporter (VvPLT1) was characterized after its heterologous expression in yeast. This H(+)-dependent plasma membrane carrier transports mannitol (K m=5.4mM) and sorbitol (K m=9.5mM) over a broad range of polyols and monosaccharides. Water-deficit stress triggered an increase in the expression of VvPLT1 at the fully mature stage, allowing increased polyol uptake into pulp cells. Plant polyol dehydrogenases are oxireductases that reversibly oxidize polyols into monosaccharides. Mannitol catabolism in grape cells (K m=30.1mM mannitol) and mature berry mesocarps (K m=79mM) was, like sorbitol dehydrogenase activity, strongly inhibited (50-75%) by water-deficit stress. Simultaneously, fructose reduction into polyols via mannitol and sorbitol dehydrogenases was stimulated, contributing to their higher intracellular concentrations in water-deficit stress. Accordingly, the concentrations of mannitol, sorbitol, galactinol, myo-inositol, and dulcitol were significantly higher in berry mesocarps from water-deficit-stressed Tempranillo grapevines. Metabolomic profiling of the berry pulp by GC-TOF-MS also revealed many other changes in its composition induced by water deficit. The impact of polyols on grape berry composition and plant response to water deficit stress, via modifications in polyol transport and metabolism, was analysed by integrating metabolomics with transcriptional analysis and biochemical approaches.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 10
Claim · model-written summary
VvPLT1 transported mannitol with a K m of 5.4mM.
VitisOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“grapevine fruit mesocarp polyol transporter (VvPLT1)”
e1“This H(+)-dependent plasma membrane carrier transports mannitol (K m=5.4mM) and sorbitol (K m=9.5mM)”
Claim · model-written summary
VvPLT1 transported sorbitol with a K m of 9.5mM.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“grapevine fruit mesocarp polyol transporter (VvPLT1)”
e1“This H(+)-dependent plasma membrane carrier transports mannitol (K m=5.4mM) and sorbitol (K m=9.5mM)”
Claim · model-written summary
Water deficit increased VvPLT1 expression at full maturity.
- Organ / stage
- fully mature stagee0
- Treatment
- Water-deficit stresse0
- Gene
- VvPLT1e0
- Outcome
- expression of VvPLT1e0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“grapevine”
e0“Water-deficit stress triggered an increase in the expression of VvPLT1 at the fully mature stage”
Claim · model-written summary
Water deficit increased polyol uptake into pulp cells.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“grapevine”
e0“allowing increased polyol uptake into pulp cells”
e1“Water-deficit stress triggered an increase in the expression of VvPLT1 at the fully mature stage”
Claim · model-written summary
Water deficit inhibited mannitol catabolism by 50-75%.
- Organ / stage
- mature berry mesocarpse0
- Treatment
- water-deficit stresse0
- Outcome
- Mannitol catabolisme0
- Direction
- inhibitede0
- Value
- 50-75%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“water-deficit stress tolerance in grapevine”
e0“Mannitol catabolism in grape cells (K m=30.1mM mannitol) and mature berry mesocarps (K m=79mM) was, like sorbitol dehydrogenase activity, strongly inhibited (50-75%) by water-deficit stress”
Claim · model-written summary
Water deficit inhibited sorbitol dehydrogenase activity by 50-75%.
- Treatment
- water-deficit stresse0
- Outcome
- sorbitol dehydrogenase activitye0
- Direction
- inhibitede0
- Value
- 50-75%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“grapevine”
e0“sorbitol dehydrogenase activity, strongly inhibited (50-75%) by water-deficit stress”
Claim · model-written summary
Water deficit stimulated fructose reduction into polyols.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“grapevine”
e0“fructose reduction into polyols via mannitol and sorbitol dehydrogenases was stimulated”
e1“Water-deficit stress triggered an increase in the expression of VvPLT1 at the fully mature stage”
Claim · model-written summary
Water deficit raised mesocarp mannitol, sorbitol and galactinol concentrations.
- Material
- Tempranilloe0
- Organ / stage
- berry mesocarpse0
- Treatment
- water-deficit-stressede0
- Outcome
- concentrations of mannitol, sorbitol, galactinole0
- Direction
- highere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“concentrations of mannitol, sorbitol, galactinol, myo-inositol, and dulcitol were significantly higher in berry mesocarps from water-deficit-stressed Tempranillo grapevines”
Claim · model-written summary
Water deficit raised mesocarp myo-inositol and dulcitol concentrations.
- Material
- Tempranilloe0
- Organ / stage
- berry mesocarpse0
- Treatment
- water-deficit-stressede0
- Outcome
- myo-inositol, and dulcitole0
- Direction
- highere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“concentrations of mannitol, sorbitol, galactinol, myo-inositol, and dulcitol were significantly higher in berry mesocarps from water-deficit-stressed Tempranillo grapevines”
Claim · model-written summary
Water deficit caused additional changes in berry pulp composition.
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“grapevine”
e0“Metabolomic profiling of the berry pulp by GC-TOF-MS also revealed many other changes in its composition induced by water deficit”
The same questions in other papers
drought · nutrient: content · VitisPositive and negative results
1 paper in the same direction as this paper · 2 in the opposite direction
- negative
- negative
- positive
drought · molecular: expression · VitisPositive and negative results
11 papers in the same direction as this paper · 6 in the opposite direction
- negative
- positive
- no effect
14 papers more in this group
See all 18 papers →drought · molecular: metabolites · VitisPositive and negative results
13 papers in the same direction as this paper · 7 in the opposite direction
- no effect
- no effect
- no effect
17 papers more in this group
See all 21 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.