Abstract
Iron availability strongly influences crop performance, yet the mechanisms in non-model horticultural species remain unclear. We combined morphological, physiological, and root transcriptome analyses to dissect the response of Capsicum annuum L. cultivar CA#8 to iron deficiency, low iron, and excess iron. Seedlings grown hydroponically under four iron supplies (0, 5, 25, and 150 μM EDTA-Fe) showed distinct shoot and root phenotypes: iron deficiency caused interveinal chlorosis and strong inhibition of root growth, excess iron induced leaf wrinkling with white spots and reduced root development, whereas low iron had milder effects. Under deficiency, rhizosphere pH decreased and ferric chelate reductase activity increased sharply, supporting activation of a Strategy I-type acquisition system. Shoot and root iron contents declined in deficient and low-iron plants but increased under excess iron, while manganese accumulated mainly in deficient shoots and zinc remained largely unchanged. Iron stress altered multiple hormones and triggered transient increases in superoxide dismutase, peroxidase, and catalase activities, consistent with regulated adjustments of the reactive oxygen species homeostasis. Root RNA-seq at two days identified 1822, 436, and 1211 differentially expressed genes under deficiency, low iron, and excess iron, respectively. Enrichment and co-expression analyses highlighted a coordinated induction or repression of iron transporters and regulators, including IRT- and NRAMP-like uptake components, YSL- and VTL-like transporters, and transcription factors and hormone-related genes linked to iron and oxidative signaling. Research indicates that pepper plants maintain iron homeostasis by integrating proton extrusion, reduction capacity, metal transport, vacuolar sequestration, and antioxidant defense mechanisms to limit damage under both iron deficiency and excess.
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 19
Claim · model-written summary
Iron deficiency caused interveinal chlorosis in pepper seedlings.
- Taxon
- Capsicum annuum L.
Capsicum annuume1 - Material
- CA#8e1
- Treatment
- iron deficiencye0
- Outcome
- interveinal chlorosise0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“iron deficiency caused interveinal chlorosis”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
Iron deficiency strongly inhibited pepper root growth.
- Taxon
- Capsicum annuum L.Capsicum annuume1
- Treatment
- iron deficiencye0
- Outcome
- root growthe0
- Direction
- inhibitione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“iron deficiency caused interveinal chlorosis and strong inhibition of root growth”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
Excess iron induced pepper leaf wrinkling with white spots.
- Taxon
- Capsicum annuum L.Capsicum annuume1
- Treatment
- excess irone0
- Outcome
- leaf wrinkling with white spotse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“excess iron induced leaf wrinkling with white spots”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
Excess iron reduced pepper root development.
- Taxon
- Capsicum annuum L.Capsicum annuume1
- Treatment
- excess irone0
- Outcome
- root developmente0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“excess iron induced leaf wrinkling with white spots and reduced root development”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
Low iron had milder phenotypic effects on pepper seedlings.
- Taxon
- Capsicum annuum L.Capsicum annuume1
- Treatment
- low irone0
- Outcome
- milder effectse0
- Direction
- mildere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“low iron had milder effects”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
Under iron deficiency, pepper rhizosphere pH decreased.
- Taxon
- Capsicum annuum L.Capsicum annuume1
- Treatment
- deficiencye0
- Outcome
- rhizosphere pHe0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under deficiency, rhizosphere pH decreased”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
Under iron deficiency, pepper ferric chelate reductase activity increased sharply.
- Taxon
- Capsicum annuum L.Capsicum annuume1
- Treatment
- deficiencye0
- Gene
- ferric chelate reductasee0
- Outcome
- ferric chelate reductase activitye0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under deficiency, rhizosphere pH decreased and ferric chelate reductase activity increased sharply”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
Shoot and root iron contents declined in iron-deficient pepper plants.
- Taxon
- Capsicum annuum L.Capsicum annuume1
- Treatment
- deficiente0
- Outcome
- Shoot and root iron contentse0
- Direction
- declinede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Shoot and root iron contents declined in deficient and low-iron plants”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
Shoot and root iron contents declined in low-iron pepper plants.
- Taxon
- Capsicum annuum L.Capsicum annuume1
- Treatment
- low-irone0
- Outcome
- Shoot and root iron contentse0
- Direction
- declinede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Shoot and root iron contents declined in deficient and low-iron plants”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
Shoot and root iron contents increased under excess iron.
- Taxon
- Capsicum annuum L.Capsicum annuume1
- Treatment
- excess irone0
- Outcome
- Shoot and root iron contentse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Shoot and root iron contents declined in deficient and low-iron plants but increased under excess iron”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
Manganese accumulated mainly in deficient pepper shoots.
- Taxon
- Capsicum annuum L.Capsicum annuume1
- Organ / stage
- shootse0
- Treatment
- deficiente0
- Outcome
- manganesee0
- Direction
- accumulatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“manganese accumulated mainly in deficient shoots”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
Pepper zinc content remained largely unchanged across iron stress.
- Taxon
- Capsicum annuum L.Capsicum annuume1
- Outcome
- zince0
- Direction
- unchangede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“zinc remained largely unchanged”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
Iron stress altered multiple hormones in pepper.
- Taxon
- Capsicum annuum L.Capsicum annuume1
- Treatment
- Iron stresse0
- Outcome
- multiple hormonese0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Iron stress altered multiple hormones”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
Iron stress transiently increased three antioxidant enzyme activities in pepper.
- Taxon
- Capsicum annuum L.Capsicum annuume1
- Treatment
- Iron stresse0
- Outcome
- superoxide dismutase, peroxidase, and catalase activitiese0
- Direction
- increasese0
- Qualifier
- transiente0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Iron stress altered multiple hormones and triggered transient increases in superoxide dismutase, peroxidase, and catalase activities”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
At two days, iron deficiency yielded 1822 differentially expressed pepper root genes.
- Taxon
- Capsicum annuum L.Capsicum annuume1
- Organ / stage
- Roote0
- Treatment
- deficiencye0
- Outcome
- differentially expressed genese0
- Value
- 1822e0
- Qualifier
- at two dayse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Root RNA-seq at two days identified 1822, 436, and 1211 differentially expressed genes under deficiency, low iron, and excess iron, respectively”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
At two days, low iron yielded 436 differentially expressed pepper root genes.
- Taxon
- Capsicum annuum L.Capsicum annuume1
- Organ / stage
- Roote0
- Treatment
- low irone0
- Outcome
- differentially expressed genese0
- Value
- 436e0
- Qualifier
- at two dayse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Root RNA-seq at two days identified 1822, 436, and 1211 differentially expressed genes under deficiency, low iron, and excess iron, respectively”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
At two days, excess iron yielded 1211 differentially expressed pepper root genes.
- Taxon
- Capsicum annuum L.Capsicum annuume1
- Organ / stage
- Roote0
- Treatment
- excess irone0
- Outcome
- differentially expressed genese0
- Value
- 1211e0
- Qualifier
- at two dayse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Root RNA-seq at two days identified 1822, 436, and 1211 differentially expressed genes under deficiency, low iron, and excess iron, respectively”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
Analyses identified coordinated regulation of iron transporters and regulatory genes in pepper roots.
- Taxon
- Capsicum annuum L.Capsicum annuume1
- Outcome
- coordinated induction or repression of iron transporters and regulatorse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Enrichment and co-expression analyses highlighted a coordinated induction or repression of iron transporters and regulators, including IRT- and NRAMP-like uptake components, YSL- and VTL-like transporters, and transcription factors and hormone-related genes linked to iron and oxidative signaling”
e1“Capsicum annuum L. cultivar CA#8”
Claim · model-written summary
The authors propose that integrated acquisition, transport, sequestration and antioxidant processes maintain pepper iron homeostasis.
- Taxon
- peppere0
- Treatment
- iron deficiency and excesse0
- Outcome
- iron homeostasise0
- Qualifier
- proton extrusion, reduction capacity, metal transport, vacuolar sequestration, and antioxidant defense mechanismse0
Not reportedDirection
Verbatim
e0“pepper plants maintain iron homeostasis by integrating proton extrusion, reduction capacity, metal transport, vacuolar sequestration, and antioxidant defense mechanisms to limit damage under both iron deficiency and excess”
The same questions in other papers
iron atom · physiology: pigments · Capsicum annuum (sweet pepper)Positive and negative results
2 papers in the same direction as this paper · 1 in the opposite direction
This paper is about lacking the nutrient, so it counts the other way round here.
- negative
- positive
- positive
iron atom · growth · Capsicum annuum (sweet pepper)Positive and negative results
2 papers in the same direction as this paper · 2 in the opposite direction
- negative
- negative
- positive
1 paper more in this group
See all 5 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.