Abstract
Hydroponically grown pea seedlings (Pisum sativum L., cv Alaska) were subjected to Fe stress for 10 to 16 days to produce mature chlorotic leaves. Greening was initiated by adding Fe to the nutrient solution. The levels of chlorophylls, chloroplast, and cytoplasmic rRNAs, and specific chloroplast- and nucleus-encoded mRNAs were all significantly lower in leaves developing during iron stress than in nonstressed leaves. In plants greening after addition of Fe, nuclear transcripts encoding chlorophyll a/b-binding protein and the small subunit of ribulose bisphosphate carboxylase/oxygenase increased about 5-fold in abundance following an 18 to 24 hour lag, as did the chloroplast-encoded transcript for the large subunit of the carboxylase/oxygenase. Chloroplast rRNA showed an increase over that in continually stressed control leaves only after a 40 hour lag. The chloroplast-encoded transcript encoding the Q(B)-binding 32 kilodalton polypeptide of Photosystem II showed little change during greening. Chlorophyll itself increased gradually after a lag period of 24 hours, with an increase in chlorophyll a slightly preceding that of chlorophyll b. Kinetic considerations suggest that the changes observed represent a coordinate series of events initiated by readdition of Fe and occurring in parallel. Though accumulation of mRNA for light-harvesting, chlorophyll-a/b-binding protein might limit chlorophyll accumulation at the onset, subsequent changes in the mRNA do not parallel chlorophyll changes. All three of the mRNAs showing recovery on addition of Fe to Fe-stressed plants undergo sharp diurnal fluctuations in abundance. Such fluctuations are comparable to those in nonstressed controls (mRNA for light-harvesting protein) or considerably more pronounced (mRNAs for carboxylase large and small subunits). The carboxylase small subunit mRNA and that for light-harvesting chlorophyll-binding protein were measured under constant conditions of light and temperature. Though a rhythm in greening leaves was hard to detect, it was prominent in the Fe-sufficient controls, persisting undamped through three full cycles for both mRNAs, and hence is probably circadian.
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 15
Claim · model-written summary
Iron stressed developing pea leaves had significantly lower chlorophyll, chloroplast and cytoplasmic rRNAs, and specific mRNAs than nonstressed leaves.
- Taxon
- Pisum sativum L.
Lathyrus oleraceust0 - Organ / stage
- leavese0
- Treatment
- iron stresse0
- Outcome
- levels of chlorophylls, chloroplast, and cytoplasmic rRNAs, and specific chloroplast- and nucleus-encoded mRNAse0
- Direction
- lowere0
- Comparator
- nonstressed leavese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The levels of chlorophylls, chloroplast, and cytoplasmic rRNAs, and specific chloroplast- and nucleus-encoded mRNAs were all significantly lower in leaves developing during iron stress than in nonstressed leaves”
t0“Pisum sativum L.”
Claim · model-written summary
On iron readdition, nuclear chlorophyll a/b binding protein and carboxylase small subunit transcripts rose about fivefold after an 18 to 24 hour lag.
- Taxon
- Pisum sativum L.Lathyrus oleraceust0
- Treatment
- Fee1
- Outcome
- nuclear transcripts encoding chlorophyll a/b-binding protein and the small subunit of ribulose bisphosphate carboxylase/oxygenasee0
- Direction
- increasede0
- Value
- about 5-folde0
- Qualifier
- 18 to 24 hour lage0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“nuclear transcripts encoding chlorophyll a/b-binding protein and the small subunit of ribulose bisphosphate carboxylase/oxygenase increased about 5-fold in abundance following an 18 to 24 hour lag”
e1“In plants greening after addition of Fe”
t0“Pisum sativum L.”
Claim · model-written summary
The chloroplast encoded carboxylase large subunit transcript also increased about fivefold after the lag.
- Taxon
- Pisum sativum L.Lathyrus oleraceust0
- Outcome
- chloroplast-encoded transcript for the large subunit of the carboxylase/oxygenasee0
Not reportedTreatmentComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“as did the chloroplast-encoded transcript for the large subunit of the carboxylase/oxygenase”
t0“Pisum sativum L.”
Claim · model-written summary
Chloroplast rRNA increased relative to stressed controls only after a 40 hour lag.
- Taxon
- Pisum sativum L.Lathyrus oleraceust0
- Outcome
- Chloroplast rRNAe0
- Direction
- increasee0
- Qualifier
- 40 hour lage0
- Comparator
- continually stressed control leavese0
Not reportedTreatment
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Chloroplast rRNA showed an increase over that in continually stressed control leaves only after a 40 hour lag”
t0“Pisum sativum L.”
Claim · model-written summary
The chloroplast encoded Photosystem II Q(B) binding protein transcript changed little during greening.
- Taxon
- Pisum sativum L.Lathyrus oleraceust0
- Outcome
- chloroplast-encoded transcript encoding the Q(B)-binding 32 kilodalton polypeptide of Photosystem IIe0
- Direction
- little changee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The chloroplast-encoded transcript encoding the Q(B)-binding 32 kilodalton polypeptide of Photosystem II showed little change during greening”
t0“Pisum sativum L.”
Claim · model-written summary
Chlorophyll rose gradually after 24 hours of lag.
- Taxon
- Pisum sativum L.Lathyrus oleraceust0
- Outcome
- Chlorophylle0
- Direction
- increasede0
- Qualifier
- 24 hourse0
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Chlorophyll itself increased gradually after a lag period of 24 hours”
t0“Pisum sativum L.”
Claim · model-written summary
Chlorophyll a increased slightly before chlorophyll b.
- Taxon
- Pisum sativum L.Lathyrus oleraceust0
- Outcome
- chlorophyll ae0
- Direction
- increasee0
- Comparator
- chlorophyll be0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“with an increase in chlorophyll a slightly preceding that of chlorophyll b”
t0“Pisum sativum L.”
Claim · model-written summary
The observed changes suggest a coordinated series initiated by iron readdition and occurring in parallel.
- Taxon
- Pisum sativum L.Lathyrus oleraceust0
- Outcome
- coordinate series of eventse0
- Qualifier
- initiated by readdition of Fe and occurring in parallele0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Kinetic considerations suggest that the changes observed represent a coordinate series of events initiated by readdition of Fe and occurring in parallel”
t0“Pisum sativum L.”
Claim · model-written summary
Light harvesting protein mRNA accumulation might limit chlorophyll accumulation at the onset.
- Taxon
- Pisum sativum L.Lathyrus oleraceust0
- Gene
- light-harvesting, chlorophyll-a/b-binding proteine0
- Outcome
- chlorophyll accumulatione0
- Qualifier
- at the onsete0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Though accumulation of mRNA for light-harvesting, chlorophyll-a/b-binding protein might limit chlorophyll accumulation at the onset”
t0“Pisum sativum L.”
Claim · model-written summary
Later light harvesting protein mRNA changes did not parallel chlorophyll changes.
- Taxon
- Pisum sativum L.Lathyrus oleraceust0
- Gene
- mRNAe0
- Outcome
- chlorophyll changese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“subsequent changes in the mRNA do not parallel chlorophyll changes”
t0“Pisum sativum L.”
Claim · model-written summary
All three recovering mRNAs showed sharp diurnal abundance fluctuations.
- Taxon
- Pisum sativum L.Lathyrus oleraceust0
- Outcome
- sharp diurnal fluctuations in abundancee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“All three of the mRNAs showing recovery on addition of Fe to Fe-stressed plants undergo sharp diurnal fluctuations in abundance”
t0“Pisum sativum L.”
Claim · model-written summary
Light harvesting mRNA fluctuations were comparable to those in nonstressed controls.
- Taxon
- Pisum sativum L.Lathyrus oleraceust0
- Gene
- mRNA for light-harvesting proteine0
- Outcome
- fluctuationse0
- Comparator
- nonstressed controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Such fluctuations are comparable to those in nonstressed controls (mRNA for light-harvesting protein)”
t0“Pisum sativum L.”
Claim · model-written summary
Carboxylase large and small subunit mRNA fluctuations were more pronounced than in nonstressed controls.
- Taxon
- Pisum sativum L.Lathyrus oleraceust0
- Outcome
- mRNAs for carboxylase large and small subunitse0
- Direction
- more pronouncede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“or considerably more pronounced (mRNAs for carboxylase large and small subunits)”
t0“Pisum sativum L.”
Claim · model-written summary
Under constant light and temperature, a rhythm was difficult to detect in greening leaves.
- Taxon
- Pisum sativum L.Lathyrus oleraceust0
- Outcome
- rhythm in greening leavese0
- Direction
- hard to detecte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Though a rhythm in greening leaves was hard to detect”
t0“Pisum sativum L.”
Claim · model-written summary
Under constant conditions, both mRNA rhythms remained prominent for three cycles in iron sufficient controls and were probably circadian.
- Taxon
- Pisum sativum L.Lathyrus oleraceust0
- Outcome
- both mRNAse0
- Value
- three full cyclese0
- Qualifier
- probably circadiane0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“it was prominent in the Fe-sufficient controls, persisting undamped through three full cycles for both mRNAs, and hence is probably circadian”
t0“Pisum sativum L.”
The same questions in other papers
iron atom · molecular: expression · Lathyrus oleraceus (pea)Positive and negative results
1 reporting no difference from an alternative
- no effect
iron atom · molecular: metabolites · Lathyrus oleraceus (pea)Positive and negative results
1 paper in the same direction as this paper · 3 in the opposite direction
- positive
- positive
- 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.