Abstract
We studied the effects of hyperhydricity on subcellular ultrastructure and physiology of leaves during in vitro regeneration of apple plants. Morphological, anatomical and ultrastructural differences between healthy leaf tissues obtained from greenhouse-grown plants and healthy and hyperhydric leaves obtained from shoots raised from nodal shoot explants in a bioreactor were investigated by electron microscopy and confocal laser scanning microscopy. Compared with healthy leaves, hyperhydric leaves showed abnormal, often discontinuous development of the epidermis and cuticle. Stomata were malformed. The leaf lamina appeared thickened and was characterized by poor differentiation between the palisade and spongy mesophyll tissue. Hyperhydric leaves had a significantly lower chloroplast number per cell and chloroplasts showed reduced thylakoid stacking compared with healthy leaves. Hyperhydricity resulted in a general decrease in concentrations of reduced and oxidized pyridine nucleotides, reflecting a reduction in metabolic activity. The activities of antioxidant enzymes, such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase were higher in hyperhydric leaves than in healthy leaves, indicating that hyperhydricity was associated with oxidative stress. Chlorophyll fluorescence measurements provided evidence of oxidative damage to the photosynthetic machinery in hyperhydric leaves: photochemical efficiency of photosystem II, effective quantum efficiency and photochemical quenching were all lower in hyperhydric leaves compared with healthy leaves.
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Claims 10
Claim · model-written summary
Hyperhydric apple leaves showed abnormal, often discontinuous development of the epidermis and cuticle compared with healthy leaves.
- Taxon
- apple
Malus domesticae0 - Organ / stage
- leavese0
- Treatment
- hyperhydricitye0
- Outcome
- development of the epidermis and cuticlee1
- Qualifier
- abnormal, often discontinuouse1
- Comparator
- healthy leavese1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We studied the effects of hyperhydricity on subcellular ultrastructure and physiology of leaves during in vitro regeneration of apple plants”
e1“Compared with healthy leaves, hyperhydric leaves showed abnormal, often discontinuous development of the epidermis and cuticle”
Claim · model-written summary
Hyperhydricity significantly lowered chloroplast number per cell compared with healthy leaves.
- Taxon
- appleMalus domesticae0
- Treatment
- hyperhydricitye0
- Outcome
- chloroplast number per celle2
- Direction
- lowere2
- Comparator
- healthy leavese2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We studied the effects of hyperhydricity on subcellular ultrastructure and physiology of leaves during in vitro regeneration of apple plants”
e2“Hyperhydric leaves had a significantly lower chloroplast number per cell and chloroplasts showed reduced thylakoid stacking compared with healthy leaves”
Claim · model-written summary
Hyperhydricity reduced thylakoid stacking in chloroplasts compared with healthy leaves.
- Taxon
- appleMalus domesticae0
- Organ / stage
- chloroplastse2
- Treatment
- hyperhydricitye0
- Outcome
- thylakoid stackinge2
- Direction
- reducede2
- Comparator
- healthy leavese2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We studied the effects of hyperhydricity on subcellular ultrastructure and physiology of leaves during in vitro regeneration of apple plants”
e2“Hyperhydric leaves had a significantly lower chloroplast number per cell and chloroplasts showed reduced thylakoid stacking compared with healthy leaves”
Claim · model-written summary
Hyperhydricity decreased the concentrations of reduced and oxidized pyridine nucleotides.
- Taxon
- appleMalus domesticae0
- Treatment
- hyperhydricitye0
- Compound
- pyridine nucleotidese3
- Outcome
- concentrations of reduced and oxidized pyridine nucleotidese3
- Direction
- decreasee3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We studied the effects of hyperhydricity on subcellular ultrastructure and physiology of leaves during in vitro regeneration of apple plants”
e3“Hyperhydricity resulted in a general decrease in concentrations of reduced and oxidized pyridine nucleotides, reflecting a reduction in metabolic activity”
Claim · model-written summary
The decrease in pyridine nucleotides is taken to reflect reduced metabolic activity in hyperhydric apple leaves.
- Taxon
- appleMalus domesticae0
- Compound
- pyridine nucleotidese3
- Outcome
- reduction in metabolic activitye3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We studied the effects of hyperhydricity on subcellular ultrastructure and physiology of leaves during in vitro regeneration of apple plants”
e3“Hyperhydricity resulted in a general decrease in concentrations of reduced and oxidized pyridine nucleotides, reflecting a reduction in metabolic activity”
Claim · model-written summary
Activities of superoxide dismutase, catalase and ascorbate peroxidase were higher in hyperhydric leaves than in healthy leaves.
- Taxon
- appleMalus domesticae0
- Treatment
- hyperhydricitye0
- Gene
- superoxide dismutase, catalase, ascorbate peroxidasee4
- Outcome
- activities of antioxidant enzymese4
- Direction
- highere4
- Comparator
- healthy leavese4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We studied the effects of hyperhydricity on subcellular ultrastructure and physiology of leaves during in vitro regeneration of apple plants”
e4“The activities of antioxidant enzymes, such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase were higher in hyperhydric leaves than in healthy leaves”
Claim · model-written summary
Glutathione reductase activity was higher in hyperhydric leaves than in healthy leaves.
- Taxon
- appleMalus domesticae0
- Treatment
- hyperhydricitye0
- Gene
- glutathione reductasee4
- Outcome
- activities of antioxidant enzymese4
- Direction
- highere4
- Comparator
- healthy leavese4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We studied the effects of hyperhydricity on subcellular ultrastructure and physiology of leaves during in vitro regeneration of apple plants”
e4“The activities of antioxidant enzymes, such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase were higher in hyperhydric leaves than in healthy leaves”
Claim · model-written summary
Hyperhydricity was associated with oxidative stress.
- Taxon
- appleMalus domesticae0
- Treatment
- hyperhydricitye5
- Outcome
- oxidative stresse5
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We studied the effects of hyperhydricity on subcellular ultrastructure and physiology of leaves during in vitro regeneration of apple plants”
e5“indicating that hyperhydricity was associated with oxidative stress”
Claim · model-written summary
Photochemical efficiency of photosystem II, effective quantum efficiency and photochemical quenching were lower in hyperhydric leaves than in healthy leaves.
- Taxon
- appleMalus domesticae0
- Treatment
- hyperhydricitye0
- Outcome
- photochemical efficiency of photosystem II, effective quantum efficiency and photochemical quenchinge6
- Direction
- lowere6
- Comparator
- healthy leavese6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We studied the effects of hyperhydricity on subcellular ultrastructure and physiology of leaves during in vitro regeneration of apple plants”
e6“Chlorophyll fluorescence measurements provided evidence of oxidative damage to the photosynthetic machinery in hyperhydric leaves: photochemical efficiency of photosystem II, effective quantum efficiency and photochemical quenching were all lower in hyperhydric leaves compared with healthy leaves”
Claim · model-written summary
Hyperhydricity was associated with oxidative damage to the photosynthetic machinery.
- Taxon
- appleMalus domesticae0
- Treatment
- hyperhydricitye0
- Outcome
- oxidative damage to the photosynthetic machinerye6
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We studied the effects of hyperhydricity on subcellular ultrastructure and physiology of leaves during in vitro regeneration of apple plants”
e6“Chlorophyll fluorescence measurements provided evidence of oxidative damage to the photosynthetic machinery in hyperhydric leaves: photochemical efficiency of photosystem II, effective quantum efficiency and photochemical quenching were all lower in hyperhydric leaves compared with healthy leaves”