Abstract
Tropospheric ozone (O3) decreases photosynthesis, growth, and yield of crop plants, while elevated carbon dioxide (CO2) has the opposite effect. The net photosynthetic rate (P N), dark respiration rate (R D), and ascorbic acid content of rice leaves were examined under combinations of O3 (0, 0.1, or 0.3 cm3 m-3, expressed as O0, O0.1, O0.3, respectively) and CO2 (400 or 800 cm3 m-3, expressed as C400 or C800, respectively). The P N declined immediately after O3 fumigation, and was larger under O0.3 than under O0.1. When C800 was combined with the O3, P N was unaffected by O0.1 and there was an approximately 20 % decrease when the rice leaves were exposed to O0.3 for 3 h. The depression of stomatal conductance (g s) observed under O0.1 was accelerated by C800, and that under O0.3 did not change because the decline under O0.3 was too large. Excluding the stomatal effect, the mesophyll P N was suppressed only by O0.3, but was substantially ameliorated when C800 was combined. Ozone fumigation boosted the R D value, whereas C800 suppressed it. An appreciable reduction of ascorbic acid occurred when the leaves were fumigated with O0.3, but the reduction was partially ameliorated by C800. The degree of visible leaf symptoms coincided with the effect of the interaction between O3 and CO2 on P N. The amelioration of O3 injury by elevated CO2 was largely attributed to the restriction of O3 intake by the leaves with stomatal closure, and partly to the maintenance of the scavenge system for reactive oxygen species that entered the leaf mesophyll, as well as the promotion of the P N.
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 16
Claim · model-written summary
O3 fumigation immediately reduced net photosynthetic rate.
- Taxon
- rice leaves
Oryza sativat0 - Treatment
- O3 fumigatione0
- Outcome
- P Ne0
- Direction
- declinede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice leaves”
e0“The P N declined immediately after O3 fumigation, and was larger under O0.3 than under O0.1.”
Claim · model-written summary
The photosynthetic decline was larger under O0.3 than O0.1.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice leaves”
e0“The P N declined immediately after O3 fumigation, and was larger under O0.3 than under O0.1.”
Claim · model-written summary
With C800, O0.1 left photosynthetic rate unaffected.
- Taxon
- rice leavesOryza sativat0
- Treatment
- O0.1e1
- Outcome
- P Ne1
- Direction
- unaffectede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice leaves”
e1“When C800 was combined with the O3, P N was unaffected by O0.1 and there was an approximately 20 % decrease when the rice leaves were exposed to O0.3 for 3 h.”
Claim · model-written summary
With C800, O0.3 reduced photosynthetic rate approximately 20% after 3 h.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice leaves”
e1“When C800 was combined with the O3, P N was unaffected by O0.1 and there was an approximately 20 % decrease when the rice leaves were exposed to O0.3 for 3 h.”
Claim · model-written summary
C800 accelerated stomatal conductance depression under O0.1.
- Taxon
- rice leavesOryza sativat0
- Treatment
- C800e2
- Outcome
- stomatal conductancee2
- Direction
- acceleratede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice leaves”
e2“The depression of stomatal conductance (g s) observed under O0.1 was accelerated by C800, and that under O0.3 did not change because the decline under O0.3 was too large.”
Claim · model-written summary
C800 did not change stomatal conductance depression under O0.3.
- Taxon
- rice leavesOryza sativat0
- Treatment
- C800e2
- Outcome
- stomatal conductancee2
- Direction
- did not changee2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice leaves”
e2“The depression of stomatal conductance (g s) observed under O0.1 was accelerated by C800, and that under O0.3 did not change because the decline under O0.3 was too large.”
Claim · model-written summary
O0.3 suppressed mesophyll photosynthetic rate beyond the stomatal effect.
- Taxon
- rice leavesOryza sativat0
- Treatment
- O0.3e3
- Outcome
- mesophyll P Ne3
- Direction
- suppressede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice leaves”
e3“Excluding the stomatal effect, the mesophyll P N was suppressed only by O0.3, but was substantially ameliorated when C800 was combined.”
Claim · model-written summary
C800 ameliorated mesophyll photosynthetic rate suppression under O0.3.
- Taxon
- rice leavesOryza sativat0
- Treatment
- C800e3
- Outcome
- mesophyll P Ne3
- Direction
- amelioratede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice leaves”
e3“Excluding the stomatal effect, the mesophyll P N was suppressed only by O0.3, but was substantially ameliorated when C800 was combined.”
Claim · model-written summary
Ozone fumigation raised dark respiration rate.
- Taxon
- rice leavesOryza sativat0
- Treatment
- Ozone fumigatione4
- Outcome
- R De4
- Direction
- boostede4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice leaves”
e4“Ozone fumigation boosted the R D value, whereas C800 suppressed it.”
Claim · model-written summary
C800 suppressed dark respiration rate.
- Taxon
- rice leavesOryza sativat0
- Treatment
- C800e4
- Outcome
- R De4
- Direction
- suppressede4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice leaves”
e4“Ozone fumigation boosted the R D value, whereas C800 suppressed it.”
Claim · model-written summary
O0.3 appreciably reduced leaf ascorbic acid.
- Taxon
- rice leavesOryza sativat0
- Treatment
- O0.3e5
- Outcome
- ascorbic acide5
- Direction
- reductione5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice leaves”
e5“An appreciable reduction of ascorbic acid occurred when the leaves were fumigated with O0.3, but the reduction was partially ameliorated by C800.”
Claim · model-written summary
C800 partially ameliorated the ascorbic acid reduction.
- Taxon
- rice leavesOryza sativat0
- Treatment
- C800e5
- Outcome
- ascorbic acide5
- Direction
- amelioratede5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice leaves”
e5“An appreciable reduction of ascorbic acid occurred when the leaves were fumigated with O0.3, but the reduction was partially ameliorated by C800.”
Claim · model-written summary
Visible leaf symptom severity coincided with the O3–CO2 effect on photosynthetic rate.
- Taxon
- rice leavesOryza sativat0
- Treatment
- O3 and CO2e6
- Outcome
- visible leaf symptomse6
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice leaves”
e6“The degree of visible leaf symptoms coincided with the effect of the interaction between O3 and CO2 on P N.”
Claim · model-written summary
Authors attributed elevated CO2 amelioration of O3 injury mainly to restricted O3 intake through stomatal closure.
- Taxon
- rice leavesOryza sativat0
- Outcome
- amelioration of O3 injurye7
- Qualifier
- restriction of O3 intake by the leaves with stomatal closuree7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice leaves”
e7“The amelioration of O3 injury by elevated CO2 was largely attributed to the restriction of O3 intake by the leaves with stomatal closure, and partly to the maintenance of the scavenge system for reactive oxygen species that entered the leaf mesophyll, as well as the promotion of the P N.”
Claim · model-written summary
Authors partly attributed injury amelioration to maintenance of a reactive oxygen species scavenging system.
- Taxon
- rice leavesOryza sativat0
- Outcome
- amelioration of O3 injurye7
- Qualifier
- maintenance of the scavenge system for reactive oxygen speciese7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice leaves”
e7“The amelioration of O3 injury by elevated CO2 was largely attributed to the restriction of O3 intake by the leaves with stomatal closure, and partly to the maintenance of the scavenge system for reactive oxygen species that entered the leaf mesophyll, as well as the promotion of the P N.”
Claim · model-written summary
Authors partly attributed injury amelioration to promoted photosynthetic rate.
- Taxon
- rice leavesOryza sativat0
- Outcome
- amelioration of O3 injurye7
- Qualifier
- promotion of the P Ne7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice leaves”
e7“The amelioration of O3 injury by elevated CO2 was largely attributed to the restriction of O3 intake by the leaves with stomatal closure, and partly to the maintenance of the scavenge system for reactive oxygen species that entered the leaf mesophyll, as well as the promotion of the P N.”
The same questions in other papers
ozone · physiology: photosynthesis · Oryza sativa (rice)Results differ
26 papers in the same direction as this paper · 2 in the opposite direction
- negative
- negative
- negative
25 papers more in this group
See all 29 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.