Abstract
Wounds and injuries incurred during preparation of fresh-cut lettuce ( Lactuca sativa L.) stimulate phenolic metabolism, which leads to tissue browning. Phenylalanine ammonia-lyase (PAL, EC 4.3.1.5.) is the first committed enzyme in the phenylpropanoid pathway and regulates its overall activity. Maximum activity of wound-induced PAL occurred sooner as the storage temperature increased from 0 to 25 °C, but the maximums were lower. A heat shock at 50 °C for 90 seconds protected fresh-cut lettuce tissue against browning, helped retain greenness, and decreased subsequent production of phenolics when applied either after or before wounding. Browning was reduced when the heat shock was applied up to 36 hours after wounding, while the maximum effect occurs around 6 hours before cutting. Like the heat-shock treatment, the protein synthesis inhibitor cycloheximide reduced wound-induced PAL activity, but it did not prevent tissue browning. When cycloheximide was applied in combination with heat-shock treatments, browning did not occur. Heat shocks may control tissue browning by more than just interfering with protein synthesis.
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Claims 11
Claim · model-written summary
A heat shock at 50 °C for 90 seconds protected fresh-cut lettuce tissue against browning.
- Taxon
- lettuce
Lactuca sativae1 - Treatment
- A heat shock at 50 °C for 90 secondse1
- Outcome
- browninge1
- Direction
- protectede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“A heat shock at 50 °C for 90 seconds protected fresh-cut lettuce tissue against browning, helped retain greenness, and decreased subsequent production of phenolics when applied either after or before wounding”
Claim · model-written summary
The heat shock helped retain greenness of fresh-cut lettuce.
- Taxon
- lettuceLactuca sativae1
- Treatment
- A heat shock at 50 °C for 90 secondse1
- Outcome
- greennesse1
- Direction
- helped retaine1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“A heat shock at 50 °C for 90 seconds protected fresh-cut lettuce tissue against browning, helped retain greenness, and decreased subsequent production of phenolics when applied either after or before wounding”
Claim · model-written summary
The heat shock decreased subsequent production of phenolics whether applied after or before wounding.
- Taxon
- lettuceLactuca sativae1
- Treatment
- A heat shock at 50 °C for 90 secondse1
- Outcome
- production of phenolicse1
- Direction
- decreasede1
- Qualifier
- when applied either after or before woundinge1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“A heat shock at 50 °C for 90 seconds protected fresh-cut lettuce tissue against browning, helped retain greenness, and decreased subsequent production of phenolics when applied either after or before wounding”
Claim · model-written summary
Browning was reduced when the heat shock was applied up to 36 hours after wounding.
- Taxon
- lettuceLactuca sativae1
- Treatment
- the heat shock was applied up to 36 hours after woundinge2
- Outcome
- Browninge2
- Direction
- reducede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“A heat shock at 50 °C for 90 seconds protected fresh-cut lettuce tissue against browning, helped retain greenness, and decreased subsequent production of phenolics when applied either after or before wounding”
e2“Browning was reduced when the heat shock was applied up to 36 hours after wounding, while the maximum effect occurs around 6 hours before cutting”
Claim · model-written summary
The maximum heat-shock effect occurs around 6 hours before cutting of lettuce.
- Taxon
- lettuceLactuca sativae1
- Outcome
- maximum effecte2
- Qualifier
- around 6 hours before cuttinge2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“A heat shock at 50 °C for 90 seconds protected fresh-cut lettuce tissue against browning, helped retain greenness, and decreased subsequent production of phenolics when applied either after or before wounding”
e2“Browning was reduced when the heat shock was applied up to 36 hours after wounding, while the maximum effect occurs around 6 hours before cutting”
Claim · model-written summary
Maximum wound-induced PAL activity occurred sooner as storage temperature increased from 0 to 25 °C.
- Taxon
- lettuceLactuca sativae1
- Treatment
- storage temperature increased from 0 to 25 °Ce3
- Gene
- PALe3
- Outcome
- Maximum activity of wound-induced PALe3
- Direction
- soonere3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“A heat shock at 50 °C for 90 seconds protected fresh-cut lettuce tissue against browning, helped retain greenness, and decreased subsequent production of phenolics when applied either after or before wounding”
e3“Maximum activity of wound-induced PAL occurred sooner as the storage temperature increased from 0 to 25 °C, but the maximums were lower”
Claim · model-written summary
The maximum wound-induced PAL activities were lower at the higher storage temperature.
- Taxon
- lettuceLactuca sativae1
- Treatment
- storage temperature increased from 0 to 25 °Ce3
- Outcome
- maximumse3
- Direction
- lowere3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“A heat shock at 50 °C for 90 seconds protected fresh-cut lettuce tissue against browning, helped retain greenness, and decreased subsequent production of phenolics when applied either after or before wounding”
e3“Maximum activity of wound-induced PAL occurred sooner as the storage temperature increased from 0 to 25 °C, but the maximums were lower”
Claim · model-written summary
Cycloheximide reduced wound-induced PAL activity in lettuce.
- Taxon
- lettuceLactuca sativae1
- Treatment
- the protein synthesis inhibitor cycloheximidee4
- Gene
- PALe4
- Outcome
- wound-induced PAL activitye4
- Direction
- reducede4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“A heat shock at 50 °C for 90 seconds protected fresh-cut lettuce tissue against browning, helped retain greenness, and decreased subsequent production of phenolics when applied either after or before wounding”
e4“Like the heat-shock treatment, the protein synthesis inhibitor cycloheximide reduced wound-induced PAL activity, but it did not prevent tissue browning”
Claim · model-written summary
Cycloheximide did not prevent tissue browning of lettuce.
- Taxon
- lettuceLactuca sativae1
- Treatment
- the protein synthesis inhibitor cycloheximidee4
- Outcome
- tissue browninge4
- Direction
- did not prevente4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“A heat shock at 50 °C for 90 seconds protected fresh-cut lettuce tissue against browning, helped retain greenness, and decreased subsequent production of phenolics when applied either after or before wounding”
e4“Like the heat-shock treatment, the protein synthesis inhibitor cycloheximide reduced wound-induced PAL activity, but it did not prevent tissue browning”
Claim · model-written summary
Cycloheximide combined with heat-shock treatments prevented browning of lettuce.
- Taxon
- lettuceLactuca sativae1
- Treatment
- cycloheximide was applied in combination with heat-shock treatmentse5
- Outcome
- browninge5
- Direction
- did not occure5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“A heat shock at 50 °C for 90 seconds protected fresh-cut lettuce tissue against browning, helped retain greenness, and decreased subsequent production of phenolics when applied either after or before wounding”
e5“When cycloheximide was applied in combination with heat-shock treatments, browning did not occur”
Claim · model-written summary
Heat shocks may control tissue browning of lettuce by more than just interfering with protein synthesis.
- Taxon
- lettuceLactuca sativae1
- Outcome
- control tissue browninge6
- Qualifier
- by more than just interfering with protein synthesise6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“A heat shock at 50 °C for 90 seconds protected fresh-cut lettuce tissue against browning, helped retain greenness, and decreased subsequent production of phenolics when applied either after or before wounding”
e6“Heat shocks may control tissue browning by more than just interfering with protein synthesis”
The same questions in other papers
protein synthesis inhibitor · disease · Lactuca sativa (garden lettuce)Results agree
1 paper in the same direction as this paper
- no effect
cycloheximide · disease · Lactuca sativa (garden lettuce)Results agree
2 papers in the same direction as this paper
- positive
- positive
heat · quality: phytochemicals · Lactuca sativa (garden lettuce)Positive and negative results
4 papers in the same direction as this paper · 1 in the opposite direction
- negative
- positive
- positive
2 papers more in this group
See all 6 papers →heat · disease · Lactuca sativa (garden lettuce)Positive and negative results
7 papers in the same direction as this paper · 2 in the opposite direction
- positive
- negative
- no effect
6 papers more in this group
See all 10 papers →heat · physiology: pigments · Lactuca sativa (garden lettuce)Results agree
2 papers in the same direction as this paper
- positive
- positive
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.