Abstract
The response of photosynthesis to absorbed light by intact leaves of wild‐type ( Hordeum vulgare L. cv. Gunilla) and chlorophyll b ‐less barley ( H. vulgare L. cv. Dornaria, chlorina‐f2 2800 ) was measured in a light integrating sphere. Up to the section where the light response curve bends most sharply the responses of the b ‐less and wild‐type barley were similar but not identical. Average quantum yield and convexity for the mutant light response curves were 0.89 and 0.90, respectively, times those of the wild‐type barley. The maximum quantum yield for PSII photochemistry was also 10% lower as indicated by fluorescence induction kinetics (F v /F m ). Just above the region where the light curve bends most sharply, photosynthesis decreased with time in the mutant but not in the wild‐type barley. This decrease was associated with a decrease in F v /F m indicating photoinhibition of PSII. This photoinhibition occurred in the same region of the light response curve where zeaxanthin formation occurs. Zeaxanthin formation occurred in both the chlorophyll b ‐less and wild‐type leaves. However, the epoxidation state was lower in the mutant than in the wild‐type barley. The results indicate that chlorophyll b ‐less mutants will have reduced photosynthetic production as a result of an increased sensitivity to photoinhibition and possibly a lowered quantum yield and convexity in the absence of photoinhibition.
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 8
Claim · model-written summary
Mutant average quantum yield was 0.89 times wild type.
- Taxon
- barley
.jpg?width=60)
Hordeum vulgaree0 - Outcome
- Average quantum yielde0
- Direction
- lowerinferrede0
- Value
- 0.89e0
- Comparator
- wild‐type barleye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Average quantum yield and convexity for the mutant light response curves were 0.89 and 0.90, respectively, times those of the wild‐type barley.”
Claim · model-written summary
Mutant convexity was 0.90 times wild type.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- convexitye0
- Direction
- lowerinferrede0
- Value
- 0.90e0
- Comparator
- wild‐type barleye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Average quantum yield and convexity for the mutant light response curves were 0.89 and 0.90, respectively, times those of the wild‐type barley.”
Claim · model-written summary
Maximum quantum yield for PSII photochemistry was 10% lower in mutant barley.
- Taxon
- barleyHordeum vulgaret0
- Outcome
- maximum quantum yield for PSII photochemistrye0
- Direction
- lowere0
- Value
- 10%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The maximum quantum yield for PSII photochemistry was also 10% lower as indicated by fluorescence induction kinetics”
t0“barley”
Claim · model-written summary
Photosynthesis decreased with time in mutant barley above the light-curve bend.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- photosynthesise0
- Direction
- decreasede0
- Comparator
- wild‐type barleye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Just above the region where the light curve bends most sharply, photosynthesis decreased with time in the mutant but not in the wild‐type barley.”
Claim · model-written summary
The photosynthetic decrease was associated with declining Fv/Fm.
- Taxon
- barleyHordeum vulgaret0
- Organ / stage
- PSIIe0
- Outcome
- F v /F me0
- Direction
- decreasee0
- Qualifier
- photoinhibition of PSIIe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This decrease was associated with a decrease in F v /F m indicating photoinhibition of PSII.”
t0“barley”
Claim · model-written summary
Zeaxanthin formed in mutant and wild-type leaves.
- Taxon
- barleyHordeum vulgaret0
- Outcome
- Zeaxanthin formatione0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Zeaxanthin formation occurred in both the chlorophyll b ‐less and wild‐type leaves.”
t0“barley”
Claim · model-written summary
Epoxidation state was lower in mutant than wild-type barley.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- epoxidation statee0
- Direction
- lowere0
- Comparator
- wild‐type barleye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the epoxidation state was lower in the mutant than in the wild‐type barley.”
Claim · model-written summary
Authors infer reduced photosynthetic production in chlorophyll b-less mutants due to greater photoinhibition sensitivity.
- Taxon
- barleyHordeum vulgaret0
- Outcome
- photosynthetic productione0
- Direction
- reducede0
- Qualifier
- increased sensitivity to photoinhibitione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“chlorophyll b ‐less mutants will have reduced photosynthetic production as a result of an increased sensitivity to photoinhibition and possibly a lowered quantum yield and convexity in the absence of photoinhibition.”
t0“barley”