Abstract
Rapid pollen tube growth requires uptake of Suc or its hydrolytic products, hexoses, from the apoplast of surrounding tissues in the style. Due to species-specific sugar requirements, reliance of pollen germination and tube growth on cell wall invertase and Suc or hexose transporters varies between species, but it is not known if plants have a sugar transporter that mediates the uptake of both hexose and Suc for pollen tube growth. Here, we show that a sugar transporter protein in apple (Malus domestica), MdSTP13a, takes up both hexose and Suc when expressed in yeast, and is essential for pollen tube growth on Glc and Suc but not on maltose. MdSTP13a-mediated direct uptake of Suc is primarily responsible for apple pollen tube growth on Suc medium. Sorbitol, a major photosynthate and transport carbohydrate in apple, modulates pollen tube growth via the MYB transcription factor MdMYB39L, which binds to the promoter of MdSTP13a to activate its expression. Antisense repression of MdSTP13a blocks sorbitol-modulated pollen tube growth. These findings demonstrate that MdSTP13a takes up both hexose and Suc for sorbitol-modulated pollen tube growth in apple, revealing a situation where acquisition of sugars for pollen tube growth is regulated by a sugar alcohol.
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Claims 6
Claim · model-written summary
MdSTP13a is essential for apple pollen tube growth on Glc and Suc but not on maltose.
- Taxon
- apple
Malus domesticae0 - Gene
- MdSTP13ae0
- Outcome
- pollen tube growthe0
- Qualifier
- on Glc and Suc but not on maltosee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a sugar transporter protein in apple (Malus domestica), MdSTP13a, takes up both hexose and Suc when expressed in yeast, and is essential for pollen tube growth on Glc and Suc but not on maltose”
Claim · model-written summary
MdSTP13a takes up both hexose and sucrose when expressed in yeast.
- Taxon
- appleMalus domesticae0
- Gene
- MdSTP13ae0
- Outcome
- takes up both hexose and Suce0
- Qualifier
- when expressed in yeaste0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a sugar transporter protein in apple (Malus domestica), MdSTP13a, takes up both hexose and Suc when expressed in yeast, and is essential for pollen tube growth on Glc and Suc but not on maltose”
Claim · model-written summary
MdSTP13a-mediated direct uptake of sucrose is primarily responsible for apple pollen tube growth on sucrose medium.
- Taxon
- appleMalus domesticae1
- Gene
- MdSTP13ae1
- Compound
- Suce1
- Outcome
- pollen tube growth on Suc mediume1
- Qualifier
- primarily responsiblee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“MdSTP13a-mediated direct uptake of Suc is primarily responsible for apple pollen tube growth on Suc medium”
Claim · model-written summary
Sorbitol modulates apple pollen tube growth via the MYB transcription factor MdMYB39L.
- Taxon
- appleMalus domesticae2
- Gene
- MdMYB39Le2
- Compound
- Sorbitole2
- Outcome
- pollen tube growthe2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“Sorbitol, a major photosynthate and transport carbohydrate in apple, modulates pollen tube growth via the MYB transcription factor MdMYB39L, which binds to the promoter of MdSTP13a to activate its expression”
Claim · model-written summary
MdMYB39L binds the promoter of MdSTP13a and activates its expression.
- Taxon
- appleMalus domesticae2
- Gene
- MdMYB39Le2
- Outcome
- activate its expressione2
- Qualifier
- binds to the promoter of MdSTP13ae2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“Sorbitol, a major photosynthate and transport carbohydrate in apple, modulates pollen tube growth via the MYB transcription factor MdMYB39L, which binds to the promoter of MdSTP13a to activate its expression”
Claim · model-written summary
Antisense repression of MdSTP13a blocked sorbitol-modulated apple pollen tube growth.
- Taxon
- appleMalus domesticae0
- Treatment
- Antisense repressione3
- Gene
- MdSTP13ae3
- Outcome
- sorbitol-modulated pollen tube growthe3
- Direction
- blockse3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a sugar transporter protein in apple (Malus domestica), MdSTP13a, takes up both hexose and Suc when expressed in yeast, and is essential for pollen tube growth on Glc and Suc but not on maltose”
e3“Antisense repression of MdSTP13a blocks sorbitol-modulated pollen tube growth”
The same questions in other papers
loss of function · growth · Malus domestica (apple)Positive and negative results
3 papers in the same direction as this paper · 5 in the opposite direction
- negative
- positive
- positive
5 papers more in this group
See all 9 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.