Abstract
summary The response of glasshouse crops to the nitrogen oxide pollutants which may be generated during enrichment with O 2 has been studied in controlled environments. Lettuce ( Lactuca sativa L. cv. Ambassador) was grown in air containing either low CO 2 , (380μmol mol −1 ), high CO 2 , (1200 μmol mol −1 ), or high CO 2 plus oxides of nitrogen? (NO x )‐ Carbondioxide enrichment increased the rate of emergence and expansion of leaves and the growth of Young plants. Addition of NO x (2μmol mol −1 NO and c. 0.5 μmol mol −1 NO 2 ) to CO 2 ‐enriched air significantly reduced the yield, compared with the ‘clean, high CO 2 treatment, without producing visible symptoms of toxicity. Fumigation of single plants in high CO 2 , with NO x rapidly inhibited photosynthesis per unit leaf area. This did not appear to be due to a reduction in stomatal conductance. Removal of NO x from the atmosphere caused a rapid and complete recovery in the rate of photosynthesis. Studies were made of the effects of growing Plants for long periods in atmospheres containing high CO 2 and NO x on the photosynthetic capacity of single leaves when measured in NO x ‐free air. The decrease in photosynthetic rate as the fourth leaf aged occurred earlier in plants grown in CO 2 ‐enriched air than in those from the low CO 2 treatment. Leaves which developed in the CO 2 ‐enriched air containing NO x did not suffer any long‐term damage to photosynthetic activity in comparison with those of the ‘clean’ high CO 2 . In mature leaves the principal long‐term effect of enrichment (with or without NO x was to reduce the rate of photosynthesis in saturating CO 2 . In contrast, there was less effect on the rate of Photosynthesis in low CO 2 . The absence of a long‐term effect of NO x , on the photosynthetic capacity suggested that photosynthesis by the lettuce crop will be inhibited only during the transient periods of NO x accumulation in the glasshouse.
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 9
Claim · model-written summary
Carbon dioxide enrichment increased emergence rate, leaf expansion, and young plant growth.
- Taxon
- lettuce
Lactuca sativat0 - Treatment
- Carbondioxide enrichmente0
- Outcome
- rate of emergence and expansion of leaves and the growth of Young plantse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“lettuce (Lactuca sativa L.)”
e0“Carbondioxide enrichment increased the rate of emergence and expansion of leaves and the growth of Young plants.”
Claim · model-written summary
Adding nitrogen oxides to enriched air reduced yield relative to clean enriched air.
- Taxon
- lettuceLactuca sativat0
- Treatment
- Addition of NO x (2μmol mol −1 NO and c. 0.5 μmol mol −1 NO 2 ) to CO 2 ‐enriched aire0
- Outcome
- yielde0
- Direction
- reducede0
- Comparator
- ‘clean, high CO 2 treatmente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“lettuce (Lactuca sativa L.)”
e0“Addition of NO x (2μmol mol −1 NO and c. 0.5 μmol mol −1 NO 2 ) to CO 2 ‐enriched air significantly reduced the yield, compared with the ‘clean, high CO 2 treatment, without producing visible symptoms of toxicity.”
Claim · model-written summary
The nitrogen oxide addition produced no visible toxicity symptoms.
- Taxon
- lettuceLactuca sativat0
- Outcome
- without producing visible symptoms of toxicitye0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“lettuce (Lactuca sativa L.)”
e0“without producing visible symptoms of toxicity”
Claim · model-written summary
Nitrogen oxides rapidly inhibited photosynthesis per leaf area in high carbon dioxide.
- Taxon
- lettuceLactuca sativat0
- Treatment
- with NO xe0
- Outcome
- photosynthesis per unit leaf areae0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“lettuce (Lactuca sativa L.)”
e0“Fumigation of single plants in high CO 2 , with NO x rapidly inhibited photosynthesis per unit leaf area.”
Claim · model-written summary
Removing nitrogen oxides rapidly restored photosynthesis.
- Taxon
- lettuceLactuca sativat0
- Treatment
- Removal of NO x from the atmospheree0
- Outcome
- rate of photosynthesise0
- Direction
- recoverye0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“lettuce (Lactuca sativa L.)”
e0“Removal of NO x from the atmosphere caused a rapid and complete recovery in the rate of photosynthesis.”
Claim · model-written summary
Photosynthesis declined earlier as the fourth leaf aged under enriched than low carbon dioxide.
- Taxon
- lettuceLactuca sativat0
- Organ / stage
- fourth leafe0
- Treatment
- CO 2 ‐enriched aire0
- Outcome
- photosynthetic ratee0
- Direction
- decreasee0
- Comparator
- low CO 2 treatmente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“lettuce (Lactuca sativa L.)”
e0“The decrease in photosynthetic rate as the fourth leaf aged occurred earlier in plants grown in CO 2 ‐enriched air than in those from the low CO 2 treatment.”
Claim · model-written summary
Leaves developed under enriched carbon dioxide plus nitrogen oxides showed no long term photosynthetic damage compared with clean enriched air.
- Taxon
- lettuceLactuca sativat0
- Treatment
- CO 2 ‐enriched air containing NO xe0
- Outcome
- photosynthetic activitye0
- Comparator
- ‘clean’ high CO 2e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“lettuce (Lactuca sativa L.)”
e0“Leaves which developed in the CO 2 ‐enriched air containing NO x did not suffer any long‐term damage to photosynthetic activity in comparison with those of the ‘clean’ high CO 2 .”
Claim · model-written summary
Enrichment reduced photosynthesis rate in saturating carbon dioxide in mature leaves.
- Taxon
- lettuceLactuca sativat0
- Organ / stage
- mature leavese0
- Treatment
- enrichment (with or without NO xe0
- Outcome
- rate of photosynthesis in saturating CO 2e0
- Direction
- reducee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“lettuce (Lactuca sativa L.)”
e0“In mature leaves the principal long‐term effect of enrichment (with or without NO x was to reduce the rate of photosynthesis in saturating CO 2 .”
Claim · model-written summary
Enrichment had less effect on photosynthesis in low carbon dioxide.
- Taxon
- lettuceLactuca sativat0
- Outcome
- rate of Photosynthesis in low CO 2e0
- Direction
- lesse0
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“lettuce (Lactuca sativa L.)”
e0“In contrast, there was less effect on the rate of Photosynthesis in low CO 2 .”
The same questions in other papers
nitric oxide · physiology: photosynthesis · Lactuca sativa (garden lettuce)Positive and negative results
1 in the opposite direction
- negative
nitric oxide · yield · Lactuca sativa (garden lettuce)Results agree
1 paper in the same direction as this paper
- no effect
co2 · yield · Lactuca sativa (garden lettuce)Results differ
3 papers in the same direction as this paper · 7 in the opposite direction
- positive
- positive
- positive
7 papers more in this group
See all 11 papers →co2 · physiology: photosynthesis · Lactuca sativa (garden lettuce)Positive and negative results
6 in the opposite direction
- positive
- positive
- positive
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.