Abstract
One-year-old `Concord' grapevines ( Vitis labrusca L.) were fertigated twice weekly for 11 weeks with a complete nutrient solution containing 1, 10, 20, 50 or 100 μmol iron (Fe) from ferric ethylenediamine di (o-hydroxyphenylacetic) acid (Fe-EDDHA). Leaf total Fe content did not increase in response to Fe supply, however both “active” Fe (extracted with 2, 2'-dipyridyl) and chlorophyll (Chl) content increased as applied Fe increased. At the lowest active Fe level, leaf absorptance and maximum PSII efficiency (Fv/Fm) were slightly decreased, and non-photochemical quenching was significantly greater. PSII quantum efficiency decreased curvilinearly as active Fe content decreased. On a Chl basis, the xanthophyll cycle pool size, lutein, and beta-carotene increased curvilinearly as active Fe decreased, and neoxanthin increased at the lowest Fe level. Activities of antioxidant enzymes superoxide dismutase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase followed a similar trend and increased under Fe deficiency, when expressed on a Chl basis. Antioxidant metabolites also increased in response to Fe limitation. On a Chl basis, ascorbate (AsA), dehydroascorbate (DAsA), reduced glutathione (GSH) and oxidized glutathione (GSSG) content was greater at the lowest active Fe levels. We did not find a difference in the ratio of AsA to DAsA or GSH to GSSG. In conclusion, both photoprotective mechanisms, xanthophyll cyle-dependent thermal dissipation and the ascorbate-glutatione antioxidant system, are enhanced in response to iron deficiency to cope with excess absorbed light.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 14
Claim · model-written summary
Leaf total iron did not increase with iron supply.
VitisNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Leaf total Fe content did not increase in response to Fe supply”
e1“grapevines”
Claim · model-written summary
Active leaf iron increased as applied iron increased.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“both “active” Fe (extracted with 2, 2'-dipyridyl) and chlorophyll (Chl) content increased as applied Fe increased”
e1“grapevines”
Claim · model-written summary
Chlorophyll content increased with applied iron.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“chlorophyll (Chl) content increased as applied Fe increased”
e1“grapevines”
Claim · model-written summary
Leaf absorptance and maximum PSII efficiency decreased slightly at the lowest active iron level.
- Compound
- active Fee0
- Outcome
- leaf absorptance and maximum PSII efficiency (Fv/Fm)e0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At the lowest active Fe level, leaf absorptance and maximum PSII efficiency (Fv/Fm) were slightly decreased”
e1“grapevines”
Claim · model-written summary
Non-photochemical quenching was greater at the lowest active iron level.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At the lowest active Fe level, leaf absorptance and maximum PSII efficiency (Fv/Fm) were slightly decreased, and non-photochemical quenching was significantly greater”
e1“grapevines”
Claim · model-written summary
PSII quantum efficiency declined as active iron declined.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“PSII quantum efficiency decreased curvilinearly as active Fe content decreased”
e1“grapevines”
Claim · model-written summary
The xanthophyll cycle pool, lutein and beta-carotene increased as active iron declined on a chlorophyll basis.
- Compound
- active Fee0
- Outcome
- xanthophyll cycle pool size, lutein, and beta-carotenee0
- Direction
- increasede0
- Qualifier
- On a Chl basise0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“On a Chl basis, the xanthophyll cycle pool size, lutein, and beta-carotene increased curvilinearly as active Fe decreased”
e1“grapevines”
Claim · model-written summary
Neoxanthin increased at the lowest iron level.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“neoxanthin increased at the lowest Fe level”
e1“grapevines”
Claim · model-written summary
Superoxide dismutase, ascorbate peroxidase and monodehydroascorbate reductase activities rose under iron deficiency.
- Treatment
- Fe deficiencye0
- Outcome
- superoxide dismutase, ascorbate peroxidase, monodehydroascorbate reductasee0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Activities of antioxidant enzymes superoxide dismutase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase followed a similar trend and increased under Fe deficiency, when expressed on a Chl basis”
e1“grapevines”
Claim · model-written summary
Dehydroascorbate reductase and glutathione reductase activities rose under iron deficiency.
- Treatment
- Fe deficiencye0
- Outcome
- dehydroascorbate reductase, and glutathione reductasee0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Activities of antioxidant enzymes superoxide dismutase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase followed a similar trend and increased under Fe deficiency, when expressed on a Chl basis”
e1“grapevines”
Claim · model-written summary
Ascorbate, dehydroascorbate and reduced glutathione were greater at the lowest active iron levels.
- Compound
- active Fee0
- Outcome
- ascorbate (AsA), dehydroascorbate (DAsA), reduced glutathione (GSH)e0
- Direction
- greatere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ascorbate (AsA), dehydroascorbate (DAsA), reduced glutathione (GSH) and oxidized glutathione (GSSG) content was greater at the lowest active Fe levels”
e1“grapevines”
Claim · model-written summary
Oxidized glutathione was greater at the lowest active iron levels.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“oxidized glutathione (GSSG) content was greater at the lowest active Fe levels”
e1“grapevines”
Claim · model-written summary
Ascorbate redox and glutathione redox ratios did not differ.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We did not find a difference in the ratio of AsA to DAsA or GSH to GSSG”
e1“grapevines”
Claim · model-written summary
The authors interpret xanthophyll thermal dissipation and the ascorbate-glutathione antioxidant system as enhanced by iron deficiency.
- Treatment
- iron deficiencye0
- Outcome
- photoprotective mechanismse0
- Qualifier
- xanthophyll cyle-dependent thermal dissipation and the ascorbate-glutatione antioxidant systeme0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“both photoprotective mechanisms, xanthophyll cyle-dependent thermal dissipation and the ascorbate-glutatione antioxidant system, are enhanced in response to iron deficiency”
e1“grapevines”
The same questions in other papers
iron atom · nutrient: content · VitisPositive and negative results
2 papers in the same direction as this paper · 8 in the opposite direction
- positive
- positive
- positive
7 papers more in this group
See all 11 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.