Abstract
The functional activities of the photosynthetic apparatus of alfalfa (Medicago sativa L.) was investigated after 24 h of dark chilling treatment at 10°C and after 48 h recovery period at 25°C and 420 μmol m -2 S-1. Dark chilling limits photosynthesis due to chilling-associated oxidative damage, which enhanced the production of active oxygen species (AOS). Dark chilling treatment resulted in a significant reduction in the CO2 assimilation rate and decreased stomatal conductance. Stomatal limitation was largely responsible for the inhibition of CO2 assimilation generated by affections in the PSII functioning and also in the Calvin cycle. Photosynthetic parameters and chlorophyll fluorescence analyses showed the same degree of inhibition during the dark chilling period. However, chlorophyll fluorescence analysis showed an increase in the process of energy dissipation in the dark chilled leaves. In addition, leaves showed a significant decrease in chlorophyll a:b ratio and higher carotenoids-to-total chlorophyll ratio providing photoprotection. Under recovery, leaves recovered photosynthetic activity thus diminishing the potential power for AOS generation.
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Claims 9
Claim · model-written summary
Dark chilling limited alfalfa photosynthesis through oxidative damage and enhanced active oxygen species production.
- Taxon
- alfalfa
Medicago sativat0 - Treatment
- Dark chillinge0
- Outcome
- photosynthesise0
- Qualifier
- chilling-associated oxidative damagee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Dark chilling limits photosynthesis due to chilling-associated oxidative damage, which enhanced the production of active oxygen species (AOS)”
t0“alfalfa”
Claim · model-written summary
Dark chilling significantly reduced CO2 assimilation.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- Dark chilling treatmente0
- Outcome
- CO2 assimilation ratee0
- Direction
- reductione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Dark chilling treatment resulted in a significant reduction in the CO2 assimilation rate”
t0“alfalfa”
Claim · model-written summary
Dark chilling decreased stomatal conductance.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- Dark chillinge1
- Outcome
- stomatal conductancee0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“decreased stomatal conductance”
t0“alfalfa”
e1“Dark chilling limits photosynthesis due to chilling-associated oxidative damage, which enhanced the production of active oxygen species (AOS)”
Claim · model-written summary
Stomatal limitation largely explained inhibited CO2 assimilation, with PSII and Calvin cycle impairment.
- Taxon
- alfalfaMedicago sativat0
- Outcome
- inhibition of CO2 assimilatione0
- Qualifier
- Stomatal limitatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Stomatal limitation was largely responsible for the inhibition of CO2 assimilation generated by affections in the PSII functioning and also in the Calvin cycle”
t0“alfalfa”
Claim · model-written summary
Photosynthetic parameters and chlorophyll fluorescence showed the same inhibition during dark chilling.
- Taxon
- alfalfaMedicago sativat0
- Outcome
- Photosynthetic parameters and chlorophyll fluorescencee0
- Direction
- inhibitione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Photosynthetic parameters and chlorophyll fluorescence analyses showed the same degree of inhibition during the dark chilling period”
t0“alfalfa”
Claim · model-written summary
Dark chilled leaves increased energy dissipation.
- Taxon
- alfalfaMedicago sativat0
- Organ / stage
- leavese0
- Outcome
- energy dissipatione0
- Direction
- increasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“chlorophyll fluorescence analysis showed an increase in the process of energy dissipation in the dark chilled leaves”
t0“alfalfa”
Claim · model-written summary
Leaf chlorophyll a:b ratio significantly decreased.
- Taxon
- alfalfaMedicago sativat0
- Organ / stage
- leavese0
- Outcome
- chlorophyll a:b ratioe0
- Direction
- decreasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“leaves showed a significant decrease in chlorophyll a:b ratio”
t0“alfalfa”
Claim · model-written summary
Leaf carotenoid to total chlorophyll ratio was higher, providing photoprotection.
- Taxon
- alfalfaMedicago sativat0
- Outcome
- carotenoids-to-total chlorophyll ratioe0
- Direction
- highere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“higher carotenoids-to-total chlorophyll ratio providing photoprotection”
t0“alfalfa”
Claim · model-written summary
Leaves recovered photosynthetic activity after recovery treatment, reducing potential AOS generation.
- Taxon
- alfalfaMedicago sativat0
- Organ / stage
- leavese0
- Outcome
- photosynthetic activitye0
- Direction
- recoverede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under recovery, leaves recovered photosynthetic activity thus diminishing the potential power for AOS generation”
t0“alfalfa”
The same questions in other papers
cold · physiology: photosynthesis · Medicago sativa (alfalfa)Positive and negative results
1 in the opposite direction
- positive
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
3 papers more in this group
See all 7 papers →cold · physiology: gas exchange · Medicago sativa (alfalfa)Results agree
1 paper in the same direction as this paper
- negative
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.