Abstract
Mechanical wound on fruit triggers the formation of reactive oxygen species (ROS) that weaken cell walls, resulting in post-harvest losses. This mechanism can be controlled by using fruit preservatives to stimulate fruit antioxidant enzyme activities for the detoxification of ROS. Chitosan is a safe and environmentally friendly preservative that modulates ROS in whole fruits and plant cells, but the effects of chitosan on the ROS metabolism of mechanically wounded apples during storage are unknown. Our study focused on exploring the effects of post-harvest chitosan treatment on ROS production, cell membrane integrity, and enzymatic and non-enzymatic antioxidant systems at fruit wounds during storage. Apple fruits (cv. Fuji) were artificially wounded, treated with 2.5% (w/v) chitosan, and stored at room temperature (21-25°C, RH = 81-85%) for 7 days. Non-wounded apples were used as healthy controls. The results showed that chitosan treatment stimulated the activities of NADPH oxidase and superoxide dismutase and increased the formation of superoxide anions and hydrogen peroxide in fruit wounds. However, malondialdehyde, lipoxygenase, and membrane permeability, which are direct biomarkers to evaluate lipid peroxidation and membrane integrity, were significantly decreased in the wounded fruits after chitosan treatment compared to the wounded control fruits. Antioxidant enzymes, such as peroxidase and catalase activities, were induced by chitosan at fruit wounds. In addition, ascorbate-glutathione cycle-related enzymes; ascorbate peroxide, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase and the content of substrates, mainly ascorbic acid, dehydroascorbate, reduced glutathione, and glutathione, were increased at fruit wounds by chitosan compared to the wounded control fruits. Our results show that wounding stimulated the production of ROS or oxidative stress. However, treatment with chitosan triggered antioxidant systems to scavenge ROS and prevent loss of fruit membrane integrity. Therefore, chitosan promises to be a favorable preservative in inducing tolerance to stress and maintaining fruit quality.
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Claims 8
Claim · model-written summary
Chitosan stimulated NADPH oxidase and superoxide dismutase activities in wounded apples.
- Taxon
- apples
Malus domesticat0 - Treatment
- chitosane0
- Outcome
- activities of NADPH oxidase and superoxide dismutasee0
- Direction
- stimulatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“chitosan treatment stimulated the activities of NADPH oxidase and superoxide dismutase and increased the formation of superoxide anions and hydrogen peroxide in fruit wounds”
t0“apples”
Claim · model-written summary
Chitosan increased superoxide anion and hydrogen peroxide formation at apple wounds.
- Taxon
- applesMalus domesticat0
- Treatment
- chitosane0
- Outcome
- formation of superoxide anions and hydrogen peroxidee0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“chitosan treatment stimulated the activities of NADPH oxidase and superoxide dismutase and increased the formation of superoxide anions and hydrogen peroxide in fruit wounds”
t0“apples”
Claim · model-written summary
Chitosan significantly decreased malondialdehyde, lipoxygenase and membrane permeability in wounded fruit.
- Taxon
- applesMalus domesticat0
- Treatment
- chitosane0
- Outcome
- malondialdehyde, lipoxygenase, and membrane permeabilitye0
- Direction
- significantly decreasede0
- Comparator
- wounded control fruitse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“malondialdehyde, lipoxygenase, and membrane permeability, which are direct biomarkers to evaluate lipid peroxidation and membrane integrity, were significantly decreased in the wounded fruits after chitosan treatment compared to the wounded control fruits”
t0“apples”
Claim · model-written summary
Chitosan induced peroxidase and catalase activities at apple wounds.
- Taxon
- applesMalus domesticat0
- Treatment
- chitosane0
- Outcome
- peroxidase and catalase activitiese0
- Direction
- inducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“peroxidase and catalase activities, were induced by chitosan at fruit wounds”
t0“apples”
Claim · model-written summary
Chitosan increased ascorbate-glutathione cycle enzyme activities at apple wounds.
- Taxon
- applesMalus domesticat0
- Treatment
- chitosane0
- Outcome
- ascorbate peroxide, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductasee0
- Direction
- increasede0
- Comparator
- wounded control fruitse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ascorbate peroxide, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase and the content of substrates, mainly ascorbic acid, dehydroascorbate, reduced glutathione, and glutathione, were increased at fruit wounds by chitosan compared to the wounded control fruits”
t0“apples”
Claim · model-written summary
Chitosan increased antioxidant substrate content at apple wounds.
- Taxon
- applesMalus domesticat0
- Treatment
- chitosane0
- Outcome
- content of substrates, mainly ascorbic acid, dehydroascorbate, reduced glutathione, and glutathionee0
- Direction
- increasede0
- Comparator
- wounded control fruitse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the content of substrates, mainly ascorbic acid, dehydroascorbate, reduced glutathione, and glutathione, were increased at fruit wounds by chitosan compared to the wounded control fruits”
t0“apples”
Claim · model-written summary
Wounding stimulated reactive oxygen species production in apples.
- Taxon
- applesMalus domesticat0
- Treatment
- woundinge0
- Outcome
- production of ROS or oxidative stresse0
- Direction
- stimulatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“wounding stimulated the production of ROS or oxidative stress”
t0“apples”
Claim · model-written summary
The authors propose chitosan as a preservative to maintain apple fruit quality.
- Taxon
- applesMalus domesticat0
- Treatment
- chitosane0
- Outcome
- maintaining fruit qualitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“chitosan promises to be a favorable preservative in inducing tolerance to stress and maintaining fruit quality”
t0“apples”
The same questions in other papers
chitosan · physiology: antioxidant enzymes · Malus domestica (apple)Results agree
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chitosan · physiology: oxidative · Malus domestica (apple)Results agree
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chitosan · quality: phytochemicals · Malus domestica (apple)Results agree
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See all 8 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.