Abstract
Photoinhibition and acclimation of photosynthesis in rice plants grown under N-sufficient (NS) and N-deficient (ND) field conditions were investigated during the tropical wet (WS) and dry (DS) seasons in the Philippines. Diurnal patterns of CO2 assimilation were examined. There was a transient peak in CO2 assimilation in the leaves of the NS plants in the early morning during the DS and the WS, which was not seen in the ND plants in either season. ND leaves had lower Ribulose bisphosphate carboxylase/oxygenase (Rubisco) contents and lower chlorophyll contents. A lowered quantum yield of photosystem II (phiPSII) was observed in the ND plants at an intermediate irradiance though no differences between N treatments were seen at high irradiance. Analysis of carotenoids indicated a small increase in the de-epoxidation state of the xanthophyll cycle (DES) at mid-day in the ND leaves compared to NS. Photoinhibition was greater in ND leaves when incident mid-day irradiance was increased by altering the leaf angle. Although Rubisco contents were lower in ND plants, photosynthesis in situ did not decline proportionally. For NS plants, Chlorophyll content, but not Rubisco content, was season-dependent and results are discussed in terms of the interaction between irradiance use and N content of rice leaves.
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 10
Claim · model-written summary
A transient early morning CO2 assimilation peak occurred in N-sufficient rice in both seasons but not N-deficient rice.
- Taxon
- rice
Oryza sativat0 - Organ / stage
- leavese0
- Outcome
- transient peak in CO2 assimilatione0
- Qualifier
- early morning during the DS and the WSe0
- Comparator
- ND plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa)”
e0“There was a transient peak in CO2 assimilation in the leaves of the NS plants in the early morning during the DS and the WS, which was not seen in the ND plants in either season.”
Claim · model-written summary
N-deficient rice leaves had lower Rubisco content.
- Taxon
- riceOryza sativat0
- Organ / stage
- leavese0
- Gene
- Ribulose bisphosphate carboxylase/oxygenase (Rubisco)e0
- Outcome
- Ribulose bisphosphate carboxylase/oxygenase (Rubisco) contentse0
- Direction
- lowere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa)”
e0“ND leaves had lower Ribulose bisphosphate carboxylase/oxygenase (Rubisco) contents and lower chlorophyll contents.”
Claim · model-written summary
N-deficient rice leaves had lower chlorophyll content.
- Taxon
- riceOryza sativat0
- Organ / stage
- leavese0
- Outcome
- chlorophyll contentse0
- Direction
- lowere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa)”
e0“ND leaves had lower Ribulose bisphosphate carboxylase/oxygenase (Rubisco) contents and lower chlorophyll contents.”
Claim · model-written summary
N-deficient rice had a lower photosystem II quantum yield at intermediate irradiance.
- Taxon
- riceOryza sativat0
- Outcome
- quantum yield of photosystem II (phiPSII)e0
- Direction
- lowerede0
- Qualifier
- at an intermediate irradiancee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa)”
e0“A lowered quantum yield of photosystem II (phiPSII) was observed in the ND plants at an intermediate irradiance”
Claim · model-written summary
At high irradiance, photosystem II quantum yield did not differ between nitrogen treatments.
- Taxon
- riceOryza sativat0
- Outcome
- differences between N treatmentse0
- Direction
- no differencese0
- Qualifier
- at high irradiancee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa)”
e0“no differences between N treatments were seen at high irradiance”
Claim · model-written summary
N-deficient leaves showed a small midday increase in xanthophyll-cycle de-epoxidation state compared with N-sufficient leaves.
- Taxon
- riceOryza sativat0
- Outcome
- de-epoxidation state of the xanthophyll cycle (DES)e0
- Direction
- increasee0
- Qualifier
- at mid-daye0
- Comparator
- NSe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa)”
e0“a small increase in the de-epoxidation state of the xanthophyll cycle (DES) at mid-day in the ND leaves compared to NS”
Claim · model-written summary
Increasing midday irradiance by changing leaf angle caused greater photoinhibition in N-deficient leaves.
- Taxon
- riceOryza sativat0
- Organ / stage
- leavese0
- Treatment
- incident mid-day irradiance was increased by altering the leaf anglee0
- Outcome
- Photoinhibitione0
- Direction
- greatere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa)”
e0“Photoinhibition was greater in ND leaves when incident mid-day irradiance was increased by altering the leaf angle.”
Claim · model-written summary
In situ photosynthesis did not decrease in proportion to Rubisco content in N-deficient rice.
- Taxon
- riceOryza sativat0
- Gene
- Rubiscoe0
- Outcome
- photosynthesis in situe0
- Direction
- did not decline proportionallye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa)”
e0“Although Rubisco contents were lower in ND plants, photosynthesis in situ did not decline proportionally.”
Claim · model-written summary
Chlorophyll content of N-sufficient rice depended on season.
- Taxon
- riceOryza sativat0
- Outcome
- Chlorophyll contente0
- Setting
- seasone0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa)”
e0“For NS plants, Chlorophyll content, but not Rubisco content, was season-dependent”
Claim · model-written summary
Rubisco content of N-sufficient rice did not depend on season.
- Taxon
- riceOryza sativat0
- Gene
- Rubiscoe0
- Outcome
- Rubisco contente0
- Direction
- note0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa)”
e0“For NS plants, Chlorophyll content, but not Rubisco content, was season-dependent”
The same questions in other papers
light · physiology: photosynthesis · Oryza sativa (rice)Results differ
22 papers in the same direction as this paper · 24 in the opposite direction
- negative
- positive
- positive
43 papers more in this group
See all 47 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.