Abstract
In this research, the lettuce high-temperature-sensitive variety Beisan San 3 was used as a test material. The effects of exogenous spermidine (Spd) on membrane lipid peroxidation, the antioxidant system, the ascorbic acid-glutathione (AsA-GSH) system and the glyoxalase (Glo) system in lettuce seedlings under high-temperature stress were studied by spraying either 1 mM spermidine or ionized water as a control. The results showed that, under high-temperature stress, the growth of lettuce seedlings was weak, and the dry weight (DW) and fresh weight (FW) were reduced by 68.9% and 82%, respectively, compared with those of the normal-temperature controls. In addition, the degree of membrane lipid peroxidation increased, and the reactive oxygen species (ROS) level increased, both of which led to a significant increase in malondialdehyde (MDA) content and lipoxygenase (LOX) activity. Under high-temperature stress, the activity of superoxide dismutase (SOD) decreased, the activities of peroxidase (POD) and catalase (CAT) increased first but then decreased, and the activity of ascorbic acid peroxidase (APX) decreased first but then increased. Glutathione reductase (GR) activity, ascorbic acid (AsA) and glutathione (GSH) content showed an upward trend under high-temperature stress. The activities of glyoxalase (GloI and GloII) in the lettuce seedling leaves increased significantly under high-temperature stress. In contrast, the application of exogenous Spd alleviated the oxidative damage to the lettuce seedlings, which showed a decrease in MDA content and LOX activity and an increase in SOD, POD, CAT, APX, GR, GloI, and GloII activities. In addition, the antioxidant AsA and GSH contents also increased to varying degrees. It can be seen from the results that high temperature stress leads to an increase in the level of ROS and cause peroxidation in lettuce seedlings, and exogenous Spd can enhance the ability of lettuce seedlings to withstand high temperature by enhancing the antioxidant system, glyoxalase system and AsA-GSH cycle system.
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Claims 13
Claim · model-written summary
Heat reduced seedling dry weight by 68.9%.
Not reportedTaxonTreatment
Verbatim
e0“dry weight (DW) and fresh weight (FW) were reduced by 68.9% and 82%, respectively, compared with those of the normal-temperature controls”
Claim · model-written summary
Heat reduced seedling fresh weight by 82%.
Not reportedTaxonTreatment
Verbatim
e0“dry weight (DW) and fresh weight (FW) were reduced by 68.9% and 82%, respectively, compared with those of the normal-temperature controls”
Claim · model-written summary
Heat increased membrane lipid peroxidation and reactive oxygen species.
Not reportedTaxonTreatmentComparator
Verbatim
e0“degree of membrane lipid peroxidation increased, and the reactive oxygen species (ROS) level increased”
Claim · model-written summary
Heat increased MDA content and LOX activity.
Not reportedTaxonTreatmentComparator
Verbatim
e0“significant increase in malondialdehyde (MDA) content and lipoxygenase (LOX) activity”
Claim · model-written summary
Heat decreased SOD activity.
- Treatment
- high-temperature stresse0
- Outcome
- activity of superoxide dismutase (SOD)e0
- Direction
- decreasede0
Not reportedTaxonComparator
Verbatim
e0“Under high-temperature stress, the activity of superoxide dismutase (SOD) decreased”
Claim · model-written summary
POD and CAT activity first increased then decreased with heat.
- Outcome
- activities of peroxidase (POD) and catalase (CAT)e0
- Direction
- increased first but then decreasede0
Not reportedTaxon
Verbatim
e0“activities of peroxidase (POD) and catalase (CAT) increased first but then decreased”
Claim · model-written summary
APX activity first decreased then increased with heat.
Not reportedTaxon
Verbatim
e0“activity of ascorbic acid peroxidase (APX) decreased first but then increased”
Claim · model-written summary
GR activity, AsA and GSH content trended upward under heat.
- Treatment
- high-temperature stresse0
- Outcome
- Glutathione reductase (GR) activity, ascorbic acid (AsA) and glutathione (GSH) contente0
- Direction
- upward trende0
Not reportedTaxonComparator
Verbatim
e0“Glutathione reductase (GR) activity, ascorbic acid (AsA) and glutathione (GSH) content showed an upward trend under high-temperature stress”
Claim · model-written summary
Heat increased glyoxalase activities in seedling leaves.
- Taxon
- lettuce
Lactuca sativae0 - Organ / stage
- seedling leavese0
- Treatment
- high-temperature stresse0
- Outcome
- activities of glyoxalase (GloI and GloII)e0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“activities of glyoxalase (GloI and GloII) in the lettuce seedling leaves increased significantly under high-temperature stress”
Claim · model-written summary
Spermidine reduced MDA content and LOX activity.
- Taxon
- lettuceLactuca sativae0
- Treatment
- exogenous Spde0
- Outcome
- MDA content and LOX activitye0
- Direction
- decreasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“application of exogenous Spd alleviated the oxidative damage to the lettuce seedlings, which showed a decrease in MDA content and LOX activity”
Claim · model-written summary
Spermidine increased SOD, POD and CAT activities.
Not reportedTaxonTreatmentComparator
Verbatim
e0“an increase in SOD, POD, CAT, APX, GR, GloI, and GloII activities”
Claim · model-written summary
Spermidine increased APX, GR and glyoxalase activities.
Not reportedTaxonTreatmentComparator
Verbatim
e0“an increase in SOD, POD, CAT, APX, GR, GloI, and GloII activities”
Claim · model-written summary
Spermidine increased AsA and GSH content.
Not reportedTaxonTreatmentComparator
Verbatim
e0“antioxidant AsA and GSH contents also increased to varying degrees”
The same questions in other papers
spermidine · physiology: oxidative · Lactuca sativa (garden lettuce)Results agree
1 paper in the same direction as this paper
- positive
heat · physiology: antioxidant enzymes · Lactuca sativa (garden lettuce)Positive and negative results
3 in the opposite direction
- positive
- 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.