Abstract
1-Methylcyclopropene (1-MCP) delays ethylene-meditated ripening of apple (Malus domestica Borkh.) fruit during controlled atmosphere (CA) storage. Here, we tested the hypothesis that 1-MCP and CA storage enhances the levels of polyamines (PAs) and 4-aminobutyrate (GABA) in apple fruit. A 46-week experiment was conducted with "Empire" apple using a split-plot design with four treatment replicates and 3°C, 2.5 kPa O2, and 0.03 or 2.5 kPa CO2 with or without 1 μL L(-1) 1-MCP. Total PA levels were not elevated by the 1-MCP treatment. Examination of the individual PAs revealed that: (i) total putrescine levels tended to be lower with 1-MCP regardless of the CO2 level, and while this was mostly at the expense of free putrescine, large transient increases in soluble conjugated putrescine were also evident; (ii) total spermidine levels tended to be lower with 1-MCP, particularly at 2.5 kPa CO2, and this was mostly at the expense of soluble conjugated spermidine; (iii) total spermine levels at 2.5 kPa CO2 tended to be lower with 1-MCP, and this was mostly at the expense of both soluble and insoluble conjugated spermine; and (iv) total spermidine and spermine levels at 0.03 kPa were relatively unaffected, compared to 2.5 kPa CO2, but transient increases in free spermidine and spermine were evident. These findings might be due to changes in the conversion of putrescine into higher PAs and the interconversion of free and conjugated forms in apple fruit, rather than altered S-adenosylmethionine availability. Regardless of 1-MCP and CO2 treatments, the availability of glutamate showed a transient peak initially, probably due to protein degradation, and this was followed by a steady decline over the remainder of the storage period which coincided with linear accumulation of GABA. This pattern has been attributed to the stimulation of glutamate decarboxylase activity and inhibition of GABA catabolism, rather than a contribution of PAs to GABA production.
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Claims 14
Claim · model-written summary
1-MCP did not elevate total polyamine levels in apple fruit.
- Taxon
- apple
Malus domesticae1 - Treatment
- 1-MCPe0
- Outcome
- Total PA levelse0
- Direction
- not elevatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Total PA levels were not elevated by the 1-MCP treatment.”
e1“apple (Malus domestica Borkh.) fruit”
Claim · model-written summary
Total putrescine tended to be lower with 1-MCP regardless of CO2 level.
- Taxon
- appleMalus domesticae1
- Treatment
- 1-MCPe0
- Outcome
- total putrescine levelse0
- Direction
- lowere0
- Qualifier
- regardless of the CO2 levele0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“total putrescine levels tended to be lower with 1-MCP regardless of the CO2 level”
e1“apple (Malus domestica Borkh.) fruit”
Claim · model-written summary
Free putrescine accounted for most of the reduction in total putrescine with 1-MCP.
- Taxon
- appleMalus domesticae2
- Treatment
- 1-MCPe1
- Outcome
- free putrescinee0
- Direction
- lowere1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“while this was mostly at the expense of free putrescine”
e1“total putrescine levels tended to be lower with 1-MCP”
e2“apple (Malus domestica Borkh.) fruit”
Claim · model-written summary
Soluble conjugated putrescine showed large transient increases under 1-MCP.
- Taxon
- appleMalus domesticae2
- Treatment
- 1-MCPe1
- Outcome
- soluble conjugated putrescinee0
- Direction
- increasese0
- Qualifier
- transiente0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“large transient increases in soluble conjugated putrescine were also evident”
e1“with 1-MCP regardless of the CO2 level”
e2“apple (Malus domestica Borkh.) fruit”
Claim · model-written summary
Total spermidine tended to be lower with 1-MCP, especially at 2.5 kPa CO2.
- Taxon
- appleMalus domesticae1
- Treatment
- 1-MCPe0
- Outcome
- total spermidine levelse0
- Direction
- lowere0
- Qualifier
- particularly at 2.5 kPa CO2e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“total spermidine levels tended to be lower with 1-MCP, particularly at 2.5 kPa CO2”
e1“apple (Malus domestica Borkh.) fruit”
Claim · model-written summary
Soluble conjugated spermidine accounted for most of the total spermidine reduction.
- Taxon
- appleMalus domesticae2
- Treatment
- 1-MCPe1
- Outcome
- soluble conjugated spermidinee0
- Direction
- lowere1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“this was mostly at the expense of soluble conjugated spermidine”
e1“total spermidine levels tended to be lower with 1-MCP”
e2“apple (Malus domestica Borkh.) fruit”
Claim · model-written summary
Total spermine at 2.5 kPa CO2 tended to be lower with 1-MCP.
- Taxon
- appleMalus domesticae1
- Treatment
- 1-MCPe0
- Outcome
- total spermine levelse0
- Direction
- lowere0
- Qualifier
- at 2.5 kPa CO2e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“total spermine levels at 2.5 kPa CO2 tended to be lower with 1-MCP”
e1“apple (Malus domestica Borkh.) fruit”
Claim · model-written summary
Soluble and insoluble conjugated spermine accounted for the lower total spermine.
- Taxon
- appleMalus domesticae2
- Treatment
- 1-MCPe1
- Outcome
- soluble and insoluble conjugated sperminee0
- Direction
- lowere1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“this was mostly at the expense of both soluble and insoluble conjugated spermine”
e1“total spermine levels at 2.5 kPa CO2 tended to be lower with 1-MCP”
e2“apple (Malus domestica Borkh.) fruit”
Claim · model-written summary
Total spermidine and spermine at 0.03 kPa were relatively unaffected compared with 2.5 kPa CO2.
- Taxon
- appleMalus domesticae1
- Treatment
- 0.03 kPae0
- Outcome
- total spermidine and spermine levelse0
- Direction
- relatively unaffectede0
- Comparator
- 2.5 kPa CO2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“total spermidine and spermine levels at 0.03 kPa were relatively unaffected, compared to 2.5 kPa CO2”
e1“apple (Malus domestica Borkh.) fruit”
Claim · model-written summary
Free spermidine and spermine showed transient increases at 0.03 kPa CO2.
- Taxon
- appleMalus domesticae2
- Outcome
- free spermidine and sperminee0
- Direction
- increasese0
- Qualifier
- at 0.03 kPae1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“transient increases in free spermidine and spermine were evident”
e1“total spermidine and spermine levels at 0.03 kPa”
e2“apple (Malus domestica Borkh.) fruit”
Claim · model-written summary
Glutamate availability peaked transiently early in storage and then declined steadily.
- Taxon
- appleMalus domesticae1
- Outcome
- availability of glutamatee0
- Direction
- steady declinee0
- Qualifier
- transient peak initiallye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the availability of glutamate showed a transient peak initially, probably due to protein degradation, and this was followed by a steady decline over the remainder of the storage period”
e1“ripening of apple (Malus domestica Borkh.) fruit”
Claim · model-written summary
GABA accumulated linearly during the storage period.
- Taxon
- appleMalus domesticae2
- Outcome
- GABAe0
- Direction
- accumulatione0
- Qualifier
- over the remainder of the storage periode1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“linear accumulation of GABA”
e1“over the remainder of the storage period”
e2“ripening of apple (Malus domestica Borkh.) fruit”
Claim · model-written summary
Changes in putrescine conversion and free versus conjugated polyamine interconversion may explain the observed polyamine findings.
- Taxon
- appleMalus domesticae0
- Outcome
- higher PAse0
- Qualifier
- changes in the conversion of putrescine into higher PAs and the interconversion of free and conjugated formse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“These findings might be due to changes in the conversion of putrescine into higher PAs and the interconversion of free and conjugated forms in apple fruit”
Claim · model-written summary
The glutamate decline and GABA accumulation pattern was attributed to stimulated glutamate decarboxylase and inhibited GABA catabolism.
- Taxon
- appleMalus domesticae1
- Gene
- glutamate decarboxylasee0
- Outcome
- GABA catabolisme0
- Qualifier
- stimulation of glutamate decarboxylase activity and inhibition of GABA catabolisme0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This pattern has been attributed to the stimulation of glutamate decarboxylase activity and inhibition of GABA catabolism”
e1“ripening of apple (Malus domestica Borkh.) fruit”
The same questions in other papers
1-methylcyclopropene · molecular: metabolites · Malus domestica (apple)Results differ
36 papers in the same direction as this paper · 15 in the opposite direction
- no effect
- no effect
- no effect
48 papers more in this group
See all 52 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.