Abstract
Pectin methylesterase (PME, EC 3.1.11) demethoxylates pectins and is believed to be involved in degradation of pectic cell wall components by polygalacturonase in ripening tomato fruit. We have introduced antisense and sense chimeric PME genes into tomato to elucidate the role of PME in fruit development and ripening. Fruits from transgenic plants expressing high levels of antisense PME RNA showed <10% of wild-type PME enzyme activity and undetectable levels of PME protein and mRNA. Lower PME enzyme activity in fruits from transgenic plants was associated with an increased molecular weight and methylesterification of pectins and decreased levels of total and chelator soluble polyuronides in cell walls. The fruits of transgenic plants also contained higher levels of soluble solids than wild-type fruits. This trait was maintained in subsequent generations and segregated in normal Mendelian fashion with the antisense PME gene. These results indicate that reduction in PME enzyme activity in ripening tomato fruits had a marked influence on fruit pectin metabolism and increased the soluble solids content of fruits, but did not interfere with the ripening process.
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Claims 7
Claim · model-written summary
Antisense PME fruit had less than 10% of wild-type PME enzyme activity.
- Taxon
- Tomato
Solanum lycopersicumt0 - Treatment
- antisense PME RNAe0
- Outcome
- PME enzyme activitye0
- Direction
- <10%e0
- Value
- <10%e0
- Comparator
- wild-typee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato Fruit”
e0“Fruits from transgenic plants expressing high levels of antisense PME RNA showed <10% of wild-type PME enzyme activity”
Claim · model-written summary
Antisense PME fruit had undetectable PME protein and mRNA.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- antisense PME RNAe0
- Outcome
- PME protein and mRNAe0
- Direction
- undetectablee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato Fruit”
e0“Fruits from transgenic plants expressing high levels of antisense PME RNA showed <10% of wild-type PME enzyme activity and undetectable levels of PME protein and mRNA”
Claim · model-written summary
Lower PME activity was associated with increased pectin molecular weight and methylesterification.
- Taxon
- TomatoSolanum lycopersicumt0
- Gene
- PMEe0
- Outcome
- molecular weight and methylesterification of pectinse0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato Fruit”
e0“Lower PME enzyme activity in fruits from transgenic plants was associated with an increased molecular weight and methylesterification of pectins”
Claim · model-written summary
Lower PME activity was associated with decreased total and chelator soluble polyuronides.
- Taxon
- TomatoSolanum lycopersicumt0
- Gene
- PMEe0
- Outcome
- total and chelator soluble polyuronidese0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato Fruit”
e0“Lower PME enzyme activity in fruits from transgenic plants was associated with an increased molecular weight and methylesterification of pectins and decreased levels of total and chelator soluble polyuronides in cell walls”
Claim · model-written summary
Transgenic fruit contained higher soluble solids than wild-type fruit.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- transgenic plantse0
- Outcome
- soluble solidse0
- Direction
- highere0
- Comparator
- wild-type fruitse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato Fruit”
e0“The fruits of transgenic plants also contained higher levels of soluble solids than wild-type fruits”
Claim · model-written summary
The elevated soluble-solids trait persisted in later generations and segregated with the antisense PME gene.
- Taxon
- TomatoSolanum lycopersicumt0
- Gene
- antisense PME genee0
- Outcome
- maintained in subsequent generations and segregated in normal Mendelian fashione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato Fruit”
e0“This trait was maintained in subsequent generations and segregated in normal Mendelian fashion with the antisense PME gene”
Claim · model-written summary
Reduced PME enzyme activity did not interfere with tomato fruit ripening.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- reduction in PME enzyme activitye0
- Outcome
- ripening processe0
- Direction
- did not interferee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato Fruit”
e0“reduction in PME enzyme activity in ripening tomato fruits had a marked influence on fruit pectin metabolism and increased the soluble solids content of fruits, but did not interfere with the ripening process”
The same questions in other papers
loss of function · molecular: expression · Solanum lycopersicum (tomato)Positive and negative results
59 papers in the same direction as this paper · 20 in the opposite direction
- positive
- positive
- no effect
76 papers more in this group
See all 80 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.