Abstract
Abstract Solar tracking has been described in several agronomic and wild species, yet variation within a given species has not been reported. To address that issue, photoperiod leaflet reorientation in response to vectorial light was measured in three alfalfa ( Medicago sativa L.) germplasm pools selected from the cultivar Ladak 65. Dark‐leaf germplasm responded to all photosynthetic photon flux densities (PPFD) (100 to 700 μmol/m 2 /s) with no detectable lag period. Following a 24‐h dark treatment only high PPFD (600 to 700μmol/m 2 /s) elicited reorientation. Pale‐leaf germplasm responded to intermediate (300 to 400 μmol/m 2 /s) and high PPFD in a similar manner; however, the low (100‐125μmol/m 2 /s) PPFD treatment had little effect on reorientation. The 24‐h dark treatment decreased reorientation at all PPFD. Small‐leaf germplasm responded equally to all PPFD and was not affected by the 24‐h dark treatment. The results suggest that available energy levels may influence the reorientation response. Carbonyl cyanide m ‐chlorophenylhydrazone, an inhibitor of photophosphorylation, and 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea, an inhibitor of non‐cyclic photosynthetic electron transport, reduced reorientation only in the pale‐leaf type. These results suggest that stored energy reserves were adequate to maintain leaflet reorientation in the absence of photosynthesis in all but the pale‐leaf germplasm. In that germplasm photosynthetically generated energy may be required to support reorientation.
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Claims 12
Claim · model-written summary
Dark-leaf germplasm reoriented under all tested PPFD levels without a detectable lag.
- Taxon
- alfalfa
Medicago sativat0 - Material
- Dark‐leaf germplasme0
- Outcome
- responded to all photosynthetic photon flux densitiese0
- Qualifier
- no detectable lag periode0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Dark‐leaf germplasm responded to all photosynthetic photon flux densities (PPFD) (100 to 700 μmol/m 2 /s) with no detectable lag period.”
t0“alfalfa”
Claim · model-written summary
After darkness, dark-leaf germplasm reoriented only at high PPFD.
- Taxon
- alfalfaMedicago sativat0
- Material
- Dark‐leaf germplasmt1
- Treatment
- 24‐h dark treatmente0
- Outcome
- reorientatione0
- Qualifier
- high PPFD (600 to 700μmol/m 2 /s)e0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Following a 24‐h dark treatment only high PPFD (600 to 700μmol/m 2 /s) elicited reorientation.”
t0“alfalfa”
t1“Dark‐leaf germplasm responded to all photosynthetic photon flux densities (PPFD) (100 to 700 μmol/m 2 /s) with no detectable lag period.”
Claim · model-written summary
Pale-leaf germplasm reoriented similarly under intermediate and high PPFD.
- Taxon
- alfalfaMedicago sativat0
- Material
- Pale‐leaf germplasme0
- Outcome
- responded to intermediate (300 to 400 μmol/m 2 /s) and high PPFDe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pale‐leaf germplasm responded to intermediate (300 to 400 μmol/m 2 /s) and high PPFD in a similar manner”
t0“alfalfa”
Claim · model-written summary
Low PPFD had little effect on pale-leaf leaflet reorientation.
- Taxon
- alfalfaMedicago sativat0
- Material
- Pale‐leaf germplasmt1
- Treatment
- low (100‐125μmol/m 2 /s) PPFD treatmente0
- Outcome
- reorientatione0
- Direction
- little effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the low (100‐125μmol/m 2 /s) PPFD treatment had little effect on reorientation.”
t0“alfalfa”
t1“Pale‐leaf germplasm responded to intermediate (300 to 400 μmol/m 2 /s) and high PPFD in a similar manner”
Claim · model-written summary
A 24-hour dark treatment decreased pale-leaf reorientation at all PPFD levels.
- Taxon
- alfalfaMedicago sativat0
- Material
- Pale‐leaf germplasmt1
- Treatment
- 24‐h dark treatmente0
- Outcome
- reorientatione0
- Direction
- decreasede0
- Qualifier
- at all PPFDe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The 24‐h dark treatment decreased reorientation at all PPFD.”
t0“alfalfa”
t1“Pale‐leaf germplasm responded to intermediate (300 to 400 μmol/m 2 /s) and high PPFD in a similar manner”
Claim · model-written summary
Small-leaf germplasm responded equally across all PPFD levels.
- Taxon
- alfalfaMedicago sativat0
- Material
- Small‐leaf germplasme0
- Outcome
- responded equally to all PPFDe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Small‐leaf germplasm responded equally to all PPFD”
t0“alfalfa”
Claim · model-written summary
Dark treatment did not affect small-leaf germplasm reorientation.
- Taxon
- alfalfaMedicago sativat0
- Material
- Small‐leaf germplasme0
- Treatment
- 24‐h dark treatmente0
- Outcome
- Small‐leaf germplasm responded equally to all PPFDe0
- Direction
- not affectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Small‐leaf germplasm responded equally to all PPFD and was not affected by the 24‐h dark treatment.”
t0“alfalfa”
Claim · model-written summary
Carbonyl cyanide m-chlorophenylhydrazone reduced reorientation only in pale-leaf germplasm.
- Taxon
- alfalfaMedicago sativat0
- Material
- pale‐leaf typee0
- Treatment
- Carbonyl cyanide m ‐chlorophenylhydrazonee0
- Outcome
- reorientatione0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Carbonyl cyanide m ‐chlorophenylhydrazone, an inhibitor of photophosphorylation, and 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea, an inhibitor of non‐cyclic photosynthetic electron transport, reduced reorientation only in the pale‐leaf type.”
t0“alfalfa”
Claim · model-written summary
3-(3,4-dichlorophenyl)-1,1-dimethylurea reduced reorientation only in pale-leaf germplasm.
- Taxon
- alfalfaMedicago sativat0
- Material
- pale‐leaf typee0
- Treatment
- 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylureae0
- Outcome
- reorientatione0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Carbonyl cyanide m ‐chlorophenylhydrazone, an inhibitor of photophosphorylation, and 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea, an inhibitor of non‐cyclic photosynthetic electron transport, reduced reorientation only in the pale‐leaf type.”
t0“alfalfa”
Claim · model-written summary
The authors suggest available energy levels influence leaflet reorientation.
- Taxon
- alfalfaMedicago sativat0
- Outcome
- reorientation responsee0
- Qualifier
- available energy levelse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The results suggest that available energy levels may influence the reorientation response.”
t0“alfalfa”
Claim · model-written summary
The authors suggest stored reserves support reorientation without photosynthesis except in pale-leaf germplasm.
- Taxon
- alfalfaMedicago sativat0
- Outcome
- leaflet reorientatione0
- Qualifier
- stored energy reservese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“These results suggest that stored energy reserves were adequate to maintain leaflet reorientation in the absence of photosynthesis in all but the pale‐leaf germplasm.”
t0“alfalfa”
Claim · model-written summary
The authors suggest pale-leaf reorientation may require photosynthetic energy.
- Taxon
- alfalfaMedicago sativat0
- Outcome
- reorientatione0
- Qualifier
- photosynthetically generated energye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In that germplasm photosynthetically generated energy may be required to support reorientation.”
t0“alfalfa”
The same questions in other papers
light · physiology: photosynthesis · Medicago sativa (alfalfa)Positive and negative results
3 papers in the same direction as this paper · 3 in the opposite direction
- positive
- positive
- positive
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See all 7 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.