Abstract
Photosynthetic gas exchange in response to increased carbon dioxide concentration ([CO2]) and drought stress of two C3 (wheat and kale) and two C4 species (Echinochloa crusgallii and Amaranthus caudatus) were analysed. Plants were grown in controlled growth chambers with ambient (350 μmol mol−1) and doubled ambient [CO2]. Drought was given by withholding water until the plants severely wilted, whereas the control plants were watered daily. Even though stomatal conductance (Gs) of C4 species either under ambient or double [CO2] was lower than those in C3, doubled [CO2] decreased Gs of all species under well watered conditions. As a result, the plants grown under doubled [CO2] transpired less water than those grown under ambient [CO2]. Photosynthesis (Pn) of the C4 species was sustained during moderate drought when those of the C3 species decreased significantly. Doubled [CO2] increased photosynthesis of C3 but not of C4 species. Increased [CO2] was only able to delay Pn reduction of all species due to the drought, but not remove it completely. The positive effects of increased [CO2] during moderate drought and the disappearance of it under severe drought suggesting that metabolic effect may limit photosynthesis under severe drought.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by-nc. 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
Stomatal conductance of C4 species was lower than that of C3 species under both ambient and doubled CO2.
Verbatim
e3“Even though stomatal conductance (Gs) of C4 species either under ambient or double [CO2] was lower than those in C3”
Claim · model-written summary
Doubled CO2 decreased stomatal conductance of all species under well-watered conditions.
Verbatim
e0“two C3 (wheat and kale) and two C4 species (Echinochloa crusgallii and Amaranthus caudatus)”
e2“Plants were grown in controlled growth chambers with ambient (350 μmol mol−1) and doubled ambient [CO2]”
e4“doubled [CO2] decreased Gs of all species under well watered conditions”
Claim · model-written summary
Doubled CO2 increased photosynthesis of wheat and kale (C3 species).
- Taxon
- wheat and kale
Brassica oleracea var. viridis
Triticum aestivume0 - Treatment
- Doubled [CO2]e5
- Outcome
- photosynthesise5
- Direction
- increasede5
- Comparator
- ambient (350 μmol mol−1)e2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“two C3 (wheat and kale) and two C4 species (Echinochloa crusgallii and Amaranthus caudatus)”
e2“Plants were grown in controlled growth chambers with ambient (350 μmol mol−1) and doubled ambient [CO2]”
e5“Doubled [CO2] increased photosynthesis of C3 but not of C4 species”
Claim · model-written summary
Doubled CO2 did not change photosynthesis of Echinochloa crusgallii and Amaranthus caudatus (C4 species).
Verbatim
e0“two C3 (wheat and kale) and two C4 species (Echinochloa crusgallii and Amaranthus caudatus)”
e2“Plants were grown in controlled growth chambers with ambient (350 μmol mol−1) and doubled ambient [CO2]”
e5“Doubled [CO2] increased photosynthesis of C3 but not of C4 species”
Claim · model-written summary
Photosynthesis (Pn) of C4 species was sustained during moderate drought.
Verbatim
e6“Photosynthesis (Pn) of the C4 species was sustained during moderate drought when those of the C3 species decreased significantly”
Claim · model-written summary
Photosynthesis (Pn) of C3 species decreased significantly during moderate drought.
Verbatim
e6“Photosynthesis (Pn) of the C4 species was sustained during moderate drought when those of the C3 species decreased significantly”
Claim · model-written summary
Increased CO2 only delayed the reduction of photosynthesis under drought in all species and did not remove it completely.
- Taxon
- two C3 (wheat and kale) and two C4 speciese0
- Treatment
- Increased [CO2]e7
- Outcome
- Pn reductione7
- Direction
- delaye7
Not reportedComparator
Verbatim
e0“two C3 (wheat and kale) and two C4 species (Echinochloa crusgallii and Amaranthus caudatus)”
e7“Increased [CO2] was only able to delay Pn reduction of all species due to the drought, but not remove it completely”
Claim · model-written summary
The benefit of increased CO2 disappears under severe drought, suggesting that a metabolic effect may limit photosynthesis under severe drought.
Verbatim
e0“two C3 (wheat and kale) and two C4 species (Echinochloa crusgallii and Amaranthus caudatus)”
e1“suggesting that metabolic effect may limit photosynthesis under severe drought”
e2“The positive effects of increased [CO2] during moderate drought and the disappearance of it under severe drought”
The same questions in other papers
co2 · physiology: photosynthesis · Brassica oleracea (wild cabbage)Positive and negative results
6 papers in the same direction as this paper · 2 in the opposite direction
- negative
- no effect
- positive
5 papers more in this group
See all 9 papers →co2 · physiology: photosynthesis · Triticum aestivum (wheat)Positive and negative results
68 papers in the same direction as this paper · 28 in the opposite direction
- negative
- negative
- no effect
93 papers more in this group
See all 97 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.