Abstract
Cell wall isolation procedures were evaluated to determine their effect on the total pectin content and the degree of methylesterification of tomato (Lycopersicon esculentum L.) fruit cell walls. Water homogenates liberate substantial amounts of buffer soluble uronic acid, 5.2 milligrams uronic acid/100 milligrams wall. Solubilization appears to be a consequence of autohydrolysis mediated by polygalacturonase II, isoenzymes A and B, since the uronic acid release from the wall residue can be suppressed by homogenization in the presence of 50% ethanol followed by heating. The extent of methylesterification in heat-inactivated cell walls, 94 mole%, was significantly greater than with water homogenates, 56 mole%. The results suggest that autohydrolysis, mediated by cell wall-associated enzymes, accounts for the solubilization of tomato fruit pectin in vitro. Endogenous enzymes also account for a decrease in the methylesterification during the cell wall preparation. The heat-inactivated cell wall preparation was superior to the other methods studied since it reduces beta-elimination during heating and inactivates constitutive enzymes that may modify pectin structure. This heat-inactivated cell wall preparation was used in subsequent enzymatic analysis of the pectin structure. Purified tomato fruit polygalacturonase and partially purified pectinmethylesterase were used to assess changes in constitutive substrates during tomato fruit ripening. Polygalacturonase treatment of heat-inactivated cell walls from mature green and breaker stages released 14% of the uronic acid. The extent of the release of polyuronides by polygalacturonase was fruit development stage dependent. At the turning stage, 21% of the pectin fraction was released, a value which increased to a maximum of 28% of the uronides at the red ripe stage. Pretreatment of the walls with purified tomato pectinesterase rendered walls from all ripening stages equally susceptible to polygalacturonase. Quantitatively, the release of uronides by polygalacturonase from all pectinesterase treated cell walls was equivalent to polygalacturonase treatment of walls at the ripe stage. Uronide polymers released by polygalacturonase contain galacturonic acid, rhamnose, galactose, arabinose, xylose, and glucose. As a function of development, an increase in the release of galacturonic acid and rhamnose was observed (40 and 6% of these polymers at the mature green stage to 54 and 15% at the red ripe stage, respectively). The amount of galactose and arabinose released by exogenous polygalacturonase decreased during development (41 and 11% from walls of mature green fruit to 11 and 6% at the red ripe stage, respectively). Minor amounts of glucose and xylose released from the wall by exogenous polygalacturonase (4-7%) remained constant throughout fruit development.
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Claims 14
Claim · model-written summary
Water homogenates released 5.2 milligrams uronic acid per 100 milligrams wall.
- Taxon
- tomato
Solanum lycopersicumt1 - Outcome
- buffer soluble uronic acide0
- Value
- 5.2 milligrams uronic acid/100 milligrams walle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Water homogenates liberate substantial amounts of buffer soluble uronic acid, 5.2 milligrams uronic acid/100 milligrams wall”
t1“Tomato”
Claim · model-written summary
Ethanol homogenization followed by heating suppressed uronic acid release from wall residue.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- homogenization in the presence of 50% ethanol followed by heatinge0
- Outcome
- uronic acid release from the wall residuee0
- Direction
- suppressede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“uronic acid release from the wall residue can be suppressed by homogenization in the presence of 50% ethanol followed by heating”
t0“Tomato”
Claim · model-written summary
Heat-inactivated cell walls had significantly greater methylesterification than water homogenates, 94 versus 56 mole%.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- heat-inactivated cell wallse0
- Outcome
- extent of methylesterificatione0
- Direction
- greatere0
- Value
- 94 mole%e0
- Qualifier
- 56 mole%e0
- Comparator
- water homogenatese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The extent of methylesterification in heat-inactivated cell walls, 94 mole%, was significantly greater than with water homogenates, 56 mole%”
t0“Tomato”
Claim · model-written summary
Heat-inactivated wall preparation was superior because it reduces beta-elimination and inactivates constitutive enzymes.
- Taxon
- TomatoSolanum lycopersicumt0
- Outcome
- superior to the other methods studiede0
- Direction
- superiore0
- Comparator
- other methods studiede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The heat-inactivated cell wall preparation was superior to the other methods studied since it reduces beta-elimination during heating and inactivates constitutive enzymes that may modify pectin structure”
t0“Tomato”
Claim · model-written summary
Polygalacturonase treatment released 14% of uronic acid from mature green and breaker stage walls.
- Taxon
- TomatoSolanum lycopersicumt0
- Organ / stage
- mature green and breaker stagese0
- Treatment
- Polygalacturonase treatmente0
- Outcome
- uronic acide0
- Direction
- releasede0
- Value
- 14%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Polygalacturonase treatment of heat-inactivated cell walls from mature green and breaker stages released 14% of the uronic acid”
t0“Tomato”
Claim · model-written summary
At the turning stage, polygalacturonase released 21% of the pectin fraction.
- Taxon
- TomatoSolanum lycopersicumt0
- Organ / stage
- turning stagee0
- Treatment
- polygalacturonaset1
- Outcome
- pectin fractione0
- Direction
- releasede0
- Value
- 21%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At the turning stage, 21% of the pectin fraction was released”
t0“Tomato”
t1“Polygalacturonase treatment”
Claim · model-written summary
At red ripe stage, polygalacturonase released a maximum 28% of uronides.
- Taxon
- TomatoSolanum lycopersicumt0
- Organ / stage
- red ripe stagee0
- Treatment
- polygalacturonaset1
- Outcome
- uronidese0
- Direction
- increasede0
- Value
- 28%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a value which increased to a maximum of 28% of the uronides at the red ripe stage”
t0“Tomato”
t1“Polygalacturonase treatment”
Claim · model-written summary
Pectinesterase pretreatment made walls from all ripening stages equally susceptible to polygalacturonase.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- Pretreatment of the walls with purified tomato pectinesterasee0
- Outcome
- susceptible to polygalacturonasee0
- Direction
- equallye0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pretreatment of the walls with purified tomato pectinesterase rendered walls from all ripening stages equally susceptible to polygalacturonase”
Claim · model-written summary
Polygalacturonase-released uronide polymers contained six named sugars.
- Taxon
- TomatoSolanum lycopersicumt0
- Outcome
- galacturonic acid, rhamnose, galactose, arabinose, xylose, and glucosee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Uronide polymers released by polygalacturonase contain galacturonic acid, rhamnose, galactose, arabinose, xylose, and glucose”
t0“Tomato”
Claim · model-written summary
Galacturonic acid release increased from 40% at mature green to 54% at red ripe stage.
- Taxon
- TomatoSolanum lycopersicumt0
- Organ / stage
- mature green stagee0
- Outcome
- release of galacturonic acide0
- Direction
- increasee0
- Value
- 40e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“an increase in the release of galacturonic acid and rhamnose was observed (40 and 6% of these polymers at the mature green stage to 54 and 15% at the red ripe stage, respectively)”
t0“Tomato”
Claim · model-written summary
Rhamnose release increased from 6% at mature green to 15% at red ripe stage.
- Taxon
- TomatoSolanum lycopersicumt0
- Organ / stage
- red ripe stagee0
- Outcome
- rhamnosee0
- Direction
- increasee0
- Value
- 15%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“an increase in the release of galacturonic acid and rhamnose was observed (40 and 6% of these polymers at the mature green stage to 54 and 15% at the red ripe stage, respectively)”
t0“Tomato”
Claim · model-written summary
Galactose release decreased during development from 41% to 11%.
- Taxon
- TomatoSolanum lycopersicumt0
- Organ / stage
- mature green fruite0
- Outcome
- galactosee0
- Direction
- decreasede0
- Value
- 41e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The amount of galactose and arabinose released by exogenous polygalacturonase decreased during development (41 and 11% from walls of mature green fruit to 11 and 6% at the red ripe stage, respectively)”
t0“Tomato”
Claim · model-written summary
Arabinose release decreased during development from 11% to 6%.
- Taxon
- TomatoSolanum lycopersicumt0
- Organ / stage
- red ripe stagee0
- Outcome
- arabinosee0
- Direction
- decreasede0
- Value
- 6%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The amount of galactose and arabinose released by exogenous polygalacturonase decreased during development (41 and 11% from walls of mature green fruit to 11 and 6% at the red ripe stage, respectively)”
t0“Tomato”
Claim · model-written summary
Glucose and xylose release remained constant at 4–7% throughout fruit development.
- Taxon
- TomatoSolanum lycopersicumt0
- Organ / stage
- fruit developmente0
- Outcome
- glucose and xylose released from the walle0
- Direction
- remained constante0
- Value
- 4-7%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Minor amounts of glucose and xylose released from the wall by exogenous polygalacturonase (4-7%) remained constant throughout fruit development”
t0“Tomato”
The same questions in other papers
ethanol · molecular: metabolites · Solanum lycopersicum (tomato)Positive and negative results
2 in the opposite direction
- negative
- no effect
heat · molecular: metabolites · Solanum lycopersicum (tomato)Positive and negative results
13 papers in the same direction as this paper · 15 in the opposite direction · 1 reporting no difference from an alternative
- negative
- negative
- negative
26 papers more in this group
See all 30 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.