Abstract
ABSTRACT Drought and elevated temperature often occur alone or in combination in many areas, limiting cool‐season grass growth. Rising atmospheric CO 2 concentration may affect plant adaptation to drought and high temperature. The objective of this study was to investigate the effectiveness of elevated CO 2 in mitigating the negative effects of drought or elevated temperature alone or a combination of these stresses on physiological processes in a perennial grass species. The effects of these treatments on water relations, photosynthesis, and respiration were determined in tall fescue ( Festuca arundinacea Schreb. cultivar Rembrandt). Grass plants were subjected to the following treatments in growth chambers: heat stress (30°C or 5°C above the optimal level of 25°C), drought stress by maintaining soil water content at 50% of field capacity, or the combined two stresses for 28 d. Stressed and unstressed control plants were exposed to a constant level of either ambient CO 2 (400 μL L −1 ) or elevated CO 2 (800 μL L −1 ). At ambient CO 2 concentration, drought and the combined stress for 28 d caused significant decline in leaf relative water content (RWC), photochemical efficiency (ratio of variable to maximum fluorescence [F v :F m ]), net photosynthetic rate ( A ), stomatal conductance (g s ), maximal ribulose‐1,5‐bisphosphate carboxylase oxygenase (Rubisco)‐limited rate of photosynthesis (V cmax ), and maximal electron transport‐limited rate of photosynthesis (J max ) but increased membrane electrolyte leakage (EL) and dark respiration rate (R d ). Elevated temperature to 5°C above the optimal level resulted in the increases in g s , EL, and R d but had no significant effects on the other physiological parameters. Drought stress for 28 d was more detrimental than increasing temperature by 5°C for tall fescue and the combined stress was more detrimental than either stress alone. Elevated CO 2 mitigated the degree of change in all physiological factors under drought or heat stress and resulted in increases in A (162%) and RWC (19%) and a reduction in EL (21%) under the combined stress. These results suggest that elevated CO 2 could improve tall fescue tolerance to drought and elevated temperature by enhancing plant water status, cellular membrane stability, and photosynthesis capacity and by suppressing g s for water loss and C consumption through lowering respiration rate.
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 12
Claim · model-written summary
Drought and combined stress significantly decreased RWC, Fv:Fm and photosynthetic rate.
- Taxon
- tall fescue
Lolium arundinaceumt0 - Treatment
- drought and the combined stress for 28 de0
- Outcome
- leaf relative water content (RWC), photochemical efficiency (ratio of variable to maximum fluorescence [F v :F m ]), net photosynthetic rate ( A )e0
- Direction
- declinee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“drought and the combined stress for 28 d caused significant decline in leaf relative water content (RWC), photochemical efficiency (ratio of variable to maximum fluorescence [F v :F m ]), net photosynthetic rate ( A )”
t0“Tall Fescue”
Claim · model-written summary
Drought and combined stress significantly decreased stomatal conductance, Vcmax and Jmax.
- Taxon
- tall fescueLolium arundinaceumt0
- Treatment
- drought and the combined stress for 28 de0
- Outcome
- stomatal conductance (g s ), maximal ribulose‐1,5‐bisphosphate carboxylase oxygenase (Rubisco)‐limited rate of photosynthesis (V cmax ), and maximal electron transport‐limited rate of photosynthesis (J max )e0
- Direction
- declinee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“drought and the combined stress for 28 d caused significant decline in leaf relative water content (RWC), photochemical efficiency (ratio of variable to maximum fluorescence [F v :F m ]), net photosynthetic rate ( A ), stomatal conductance (g s ), maximal ribulose‐1,5‐bisphosphate carboxylase oxygenase (Rubisco)‐limited rate of photosynthesis (V cmax ), and maximal electron transport‐limited rate of photosynthesis (J max )”
t0“Tall Fescue”
Claim · model-written summary
Drought and combined stress increased electrolyte leakage and dark respiration.
- Taxon
- tall fescueLolium arundinaceumt0
- Treatment
- drought and the combined stress for 28 de0
- Outcome
- membrane electrolyte leakage (EL) and dark respiration rate (R d )e0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“drought and the combined stress for 28 d caused significant decline in leaf relative water content (RWC), photochemical efficiency (ratio of variable to maximum fluorescence [F v :F m ]), net photosynthetic rate ( A ), stomatal conductance (g s ), maximal ribulose‐1,5‐bisphosphate carboxylase oxygenase (Rubisco)‐limited rate of photosynthesis (V cmax ), and maximal electron transport‐limited rate of photosynthesis (J max ) but increased membrane electrolyte leakage (EL) and dark respiration rate (R d )”
t0“Tall Fescue”
Claim · model-written summary
Heat increased stomatal conductance, electrolyte leakage and dark respiration.
- Taxon
- tall fescueLolium arundinaceumt0
- Treatment
- Elevated temperature to 5°C above the optimal levele0
- Outcome
- g s , EL, and R de0
- Direction
- increasese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Elevated temperature to 5°C above the optimal level resulted in the increases in g s , EL, and R d”
t0“Tall Fescue”
Claim · model-written summary
Heat did not significantly affect the other measured physiological parameters.
- Taxon
- Tall FescueLolium arundinaceumt1
- Treatment
- Elevated Temperaturet0
- Outcome
- other physiological parameterse0
- Direction
- no significant effectse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“had no significant effects on the other physiological parameters”
t0“Elevated Temperature, Drought Stress, and the Combined Stresses”
t1“Tall Fescue”
Claim · model-written summary
Drought was more detrimental than a 5°C temperature increase.
- Taxon
- tall fescueLolium arundinaceume0
- Treatment
- Drought stress for 28 de0
- Outcome
- more detrimentale0
- Direction
- more detrimentale0
- Comparator
- increasing temperature by 5°Ce0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Drought stress for 28 d was more detrimental than increasing temperature by 5°C for tall fescue”
Claim · model-written summary
Combined stress was more detrimental than either stress alone.
- Taxon
- tall fescueLolium arundinaceumt0
- Treatment
- combined stresse0
- Outcome
- more detrimentale0
- Direction
- more detrimentale0
- Comparator
- either stress alonee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the combined stress was more detrimental than either stress alone”
t0“Tall Fescue”
Claim · model-written summary
Elevated CO2 mitigated changes in all physiological factors under drought or heat.
- Taxon
- tall fescueLolium arundinaceumt0
- Treatment
- Elevated CO 2e0
- Outcome
- degree of change in all physiological factorse0
- Direction
- mitigatede0
- Qualifier
- under drought or heat stresse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Elevated CO 2 mitigated the degree of change in all physiological factors under drought or heat stress”
t0“Tall Fescue”
Claim · model-written summary
Under combined stress, elevated CO2 increased photosynthetic rate by 162%.
- Taxon
- tall fescueLolium arundinaceumt0
- Treatment
- Elevated CO2t0
- Outcome
- Ae0
- Direction
- increasese0
- Value
- 162%e0
- Qualifier
- under the combined stresse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“resulted in increases in A (162%) and RWC (19%) and a reduction in EL (21%) under the combined stress”
t0“Elevated CO2 on Physiological Responses of Tall Fescue”
Claim · model-written summary
Under combined stress, elevated CO2 increased RWC by 19%.
- Taxon
- tall fescueLolium arundinaceumt0
- Treatment
- Elevated CO2t0
- Outcome
- RWCe0
- Direction
- increasese0
- Value
- 19%e0
- Qualifier
- under the combined stresse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“resulted in increases in A (162%) and RWC (19%) and a reduction in EL (21%) under the combined stress”
t0“Elevated CO2 on Physiological Responses of Tall Fescue”
Claim · model-written summary
Under combined stress, elevated CO2 reduced electrolyte leakage by 21%.
- Taxon
- tall fescueLolium arundinaceumt0
- Treatment
- Elevated CO2t0
- Outcome
- ELe0
- Direction
- reductione0
- Value
- 21%e0
- Qualifier
- under the combined stresse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“resulted in increases in A (162%) and RWC (19%) and a reduction in EL (21%) under the combined stress”
t0“Elevated CO2 on Physiological Responses of Tall Fescue”
Claim · model-written summary
The authors suggest elevated CO2 could improve tall fescue stress tolerance through water status, membranes, photosynthesis, conductance and respiration.
- Taxon
- tall fescueLolium arundinaceume0
- Treatment
- elevated CO 2e0
- Outcome
- tolerance to drought and elevated temperaturee0
- Qualifier
- enhancing plant water status, cellular membrane stability, and photosynthesis capacity and by suppressing g s for water loss and C consumption through lowering respiration ratee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“elevated CO 2 could improve tall fescue tolerance to drought and elevated temperature by enhancing plant water status, cellular membrane stability, and photosynthesis capacity and by suppressing g s for water loss and C consumption through lowering respiration rate”
The same questions in other papers
drought · physiology: water · Lolium arundinaceum (tall fescue)Positive and negative results
3 in the opposite direction
- positive
- positive
- positive
co2 · physiology: water · Lolium arundinaceum (tall fescue)Positive and negative results
2 papers in the same direction as this paper · 1 in the opposite direction
- no effect
- positive
- positive
heat · physiology: oxidative · Lolium arundinaceum (tall fescue)Positive and negative results
3 papers in the same direction as this paper · 2 in the opposite direction
- positive
- positive
- negative
2 papers more in this group
See all 6 papers →drought · physiology: photosynthesis · Lolium arundinaceum (tall fescue)Positive and negative results
4 papers in the same direction as this paper · 2 in the opposite direction
- positive
- positive
- negative
3 papers more in this group
See all 7 papers →drought · physiology: oxidative · Lolium arundinaceum (tall fescue)Positive and negative results
5 papers in the same direction as this paper · 1 in the opposite direction
- positive
- no effect
- negative
3 papers more in this group
See all 7 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.