Abstract
Fluorescence emission spectral peaks at 685, 695 and 730 nanometers (F685, F695, and F730) were recorded 77 K from diluted leaf tissue and epidermal powders prepared from Saxifraga cernua. The time course for state 1 to state 2 transitions was monitored as changes in the ratios of the three emission peaks. During illumination with light 2 (580 nm) the F730/F695 and F730/F685 ratios increased within minutes to establish a condition characteristic of state 2. A major difference between the two chloroplast types was the more rapid establishment of state 2 by mesophyll chloroplasts. An increase in light 2 intensity caused an increase in the magnitude of the F730/F695 ratio for both chloroplast types and, for guard cell chloroplasts, a decrease in the time required to establish the new ratio. The role of reversible phosphorylation of the light-harvesting chlorophyll a/b protein complex in regulating state transitions for both mesophyll and guard cell chloroplasts was assessed using DCMU and sodium fluoride, a specific phosphatase inhibitor. DCMU-treated mesophyll and epidermal tissues failed to show a state 1-state 2 transition. NaF-treated tissues attained state 2 but lacked the ability to revert back to state 1.
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Claims 6
Claim · model-written summary
Light 2 raised two fluorescence ratios within minutes.
- Taxon
- Saxifraga cernua
Saxifraga cernuae7 - Treatment
- light 2 (580 nm)e0
- Outcome
- F730/F695 and F730/F685 ratiose0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“During illumination with light 2 (580 nm) the F730/F695 and F730/F685 ratios increased within minutes to establish a condition characteristic of state 2.”
e7“prepared from Saxifraga cernua”
Claim · model-written summary
Mesophyll chloroplasts established state 2 more rapidly than guard cell chloroplasts.
- Taxon
- Saxifraga cernuaSaxifraga cernuae7
- Organ / stage
- mesophyll chloroplastse0
- Outcome
- more rapid establishment of state 2e0
- Direction
- more rapide0
- Comparator
- two chloroplast typese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A major difference between the two chloroplast types was the more rapid establishment of state 2 by mesophyll chloroplasts.”
e7“prepared from Saxifraga cernua”
Claim · model-written summary
Higher light 2 intensity increased the F730/F695 ratio in both chloroplast types.
- Taxon
- Saxifraga cernuaSaxifraga cernuae7
- Treatment
- increase in light 2 intensitye0
- Outcome
- magnitude of the F730/F695 ratioe0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“An increase in light 2 intensity caused an increase in the magnitude of the F730/F695 ratio for both chloroplast types and, for guard cell chloroplasts, a decrease in the time required to establish the new ratio.”
e7“prepared from Saxifraga cernua”
Claim · model-written summary
Higher light 2 intensity shortened the time for guard cell chloroplasts to attain the new ratio.
- Taxon
- Saxifraga cernuaSaxifraga cernuae7
- Organ / stage
- guard cell chloroplastse0
- Treatment
- increase in light 2 intensitye0
- Outcome
- time required to establish the new ratioe0
- Direction
- decreasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“An increase in light 2 intensity caused an increase in the magnitude of the F730/F695 ratio for both chloroplast types and, for guard cell chloroplasts, a decrease in the time required to establish the new ratio.”
e7“prepared from Saxifraga cernua”
Claim · model-written summary
DCMU-treated mesophyll and epidermal tissues did not transition to state 2.
- Taxon
- Saxifraga cernuaSaxifraga cernuae7
- Organ / stage
- mesophyll and epidermal tissuese0
- Treatment
- DCMU-treatede0
- Outcome
- failed to show a state 1-state 2 transitione0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“DCMU-treated mesophyll and epidermal tissues failed to show a state 1-state 2 transition.”
e7“prepared from Saxifraga cernua”
Claim · model-written summary
NaF-treated tissues reached state 2 but could not return to state 1.
- Taxon
- Saxifraga cernuaSaxifraga cernuae7
- Treatment
- NaF-treatede0
- Outcome
- attained state 2 but lacked the ability to revert back to state 1e0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“NaF-treated tissues attained state 2 but lacked the ability to revert back to state 1.”
e7“prepared from Saxifraga cernua”