Abstract
Uptake and translocation of labelled iron were studied in sunflower ( Helianthus annuus L. cv. Sobrid) grown in nutrient solution with low FeEDDHA concentrations during preculture. In contrast to conditions for plants adequately supplied with iron, suboptimal iron supply leads to temporary Fe stress with rhythmic rates of uptake and translocation of iron (period 2–4 days). This rhythmic behaviour of iron uptake is associated with corresponding changes in morphology (thickening of root tips) and physiology (increase in reducing capacity) of the roots. Iron stress is alleviated within less than one day if sufficient iron is available. This is indicated by normalisation of root morphology, reducing capacity and rate of iron uptake and translocation. This rhythm in iron uptake stresses the importance of rhythmic patterns of biochemical behaviour in complex biological systems. It is suggested that phytohormones are involved in the transformation of the iron nutritional status of the shoot apex into a “signal” for the uptake sites of iron in the roots. Preliminary experiments with sunflower in calcareous soil indicate an ecological importance of this fine regulation mechanism for plants on soil with a low iron availability, manifested in rhythmic iron stress reactions.
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Claims 5
Claim · model-written summary
Suboptimal iron supply induced temporary rhythmic iron uptake and translocation stress.
- Taxon
- sunflower
Helianthus annuust0 - Treatment
- suboptimal iron supplye0
- Outcome
- rhythmic rates of uptake and translocation of irone0
- Value
- 2–4 dayse0
- Comparator
- plants adequately supplied with irone0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In contrast to conditions for plants adequately supplied with iron, suboptimal iron supply leads to temporary Fe stress with rhythmic rates of uptake and translocation of iron (period 2–4 days)”
t0“sunflower”
Claim · model-written summary
Rhythmic uptake coincided with root tip thickening and increased reducing capacity.
- Taxon
- sunflowerHelianthus annuust0
- Organ / stage
- rootse0
- Outcome
- reducing capacitye0
- Direction
- increasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This rhythmic behaviour of iron uptake is associated with corresponding changes in morphology (thickening of root tips) and physiology (increase in reducing capacity) of the roots”
t0“sunflower”
Claim · model-written summary
Sufficient iron alleviated iron stress within less than one day and normalized root traits and iron uptake.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- sufficient irone0
- Outcome
- Iron stresse0
- Direction
- alleviatede0
- Value
- less than one daye0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Iron stress is alleviated within less than one day if sufficient iron is available. This is indicated by normalisation of root morphology, reducing capacity and rate of iron uptake and translocation”
t0“sunflower”
Claim · model-written summary
The authors suggest phytohormones mediate shoot-to-root signaling of iron status.
- Taxon
- sunflowerHelianthus annuust0
- Compound
- phytohormonese0
- Outcome
- uptake sites of iron in the rootse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“It is suggested that phytohormones are involved in the transformation of the iron nutritional status of the shoot apex into a “signal” for the uptake sites of iron in the roots”
t0“sunflower”
Claim · model-written summary
Preliminary calcareous-soil experiments indicated rhythmic iron stress in sunflower.
- Taxon
- sunflowerHelianthus annuuse0
- Outcome
- rhythmic iron stress reactionse0
- Setting
- calcareous soile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Preliminary experiments with sunflower in calcareous soil indicate an ecological importance of this fine regulation mechanism for plants on soil with a low iron availability, manifested in rhythmic iron stress reactions”
The same questions in other papers
iron atom · nutrient: content · Helianthus annuus (common sunflower)Positive and negative results
7 papers in the same direction as this paper · 2 in the opposite direction
- negative
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6 papers more in this group
See all 10 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.