Abstract
Abstract Tobacco gaseous treatments The extent of root and shoot injury of tobacco plants exposed to various gaseous treatments (O 2 , CO 2 , N 2 ) in the root environment was determined by microscopic examination of roots, stem diameter changes, and shoot measurements. An attempt was also made to determine the relative importance of O 2 deficiency and CO 2 excess in causing the observed injury. The plants were grown in an environmental control chamber with roots in an intermittent solution mist in airtight chambers. Oxygen levels of 2.5%, with and without 18.5% CO 2 , the remainder being N 2 , caused no apparent reduction in root or shoot growth. One percent O 2 plus 99% N 2 treatments for 24 or 48 hours reduced the rate of growth during treatment; but the plants resumed a normal rate of growth during recovery. One percent O 2 plus 20% CO 2 plus 79% N 2 treatments for 24 or 48 hours caused death of several root tips, chlorosis of the lower leaves, necrotic areas on some other leaves, and considerable reduction in the rate of growth during treatment. Treatments with pure N 2 for 12 hours caused growth to cease for 60 hours. Treatments with pure N 2 for 24 hours resulted in death of the root system within 4 days. Treatments with 21% CO 2 for 24 hours killed the plants more quickly than did pure N 2 .
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Claims 10
Claim · model-written summary
At 2.5% oxygen, with or without 18.5% carbon dioxide, tobacco showed no apparent reduction in root or shoot growth.
- Taxon
- Nicotiana tabacum L.
Nicotiana tabacumt0 - Treatment
- Oxygen levels of 2.5%, with and without 18.5% CO 2 , the remainder being N 2e0
- Outcome
- root or shoot growthe0
- Direction
- no apparent reductione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Oxygen levels of 2.5%, with and without 18.5% CO 2 , the remainder being N 2 , caused no apparent reduction in root or shoot growth.”
t0“Nicotiana tabacum L.”
Claim · model-written summary
One percent oxygen plus 99% nitrogen for 24 or 48 hours reduced tobacco growth rate during treatment.
- Taxon
- Nicotiana tabacum L.Nicotiana tabacumt0
- Treatment
- One percent O 2 plus 99% N 2 treatments for 24 or 48 hourse0
- Outcome
- rate of growthe0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“One percent O 2 plus 99% N 2 treatments for 24 or 48 hours reduced the rate of growth during treatment; but the plants resumed a normal rate of growth during recovery.”
t0“Nicotiana tabacum L.”
Claim · model-written summary
After 1% oxygen and 99% nitrogen treatment, tobacco resumed a normal growth rate during recovery.
- Taxon
- Nicotiana tabacum L.Nicotiana tabacumt0
- Outcome
- normal rate of growthe0
- Direction
- resumede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“but the plants resumed a normal rate of growth during recovery.”
t0“Nicotiana tabacum L.”
Claim · model-written summary
One percent oxygen with 20% carbon dioxide and 79% nitrogen for 24 or 48 hours killed several tobacco root tips.
- Taxon
- Nicotiana tabacum L.Nicotiana tabacumt0
- Organ / stage
- root tipse0
- Treatment
- One percent O 2 plus 20% CO 2 plus 79% N 2 treatments for 24 or 48 hourse0
- Outcome
- death of several root tipse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“One percent O 2 plus 20% CO 2 plus 79% N 2 treatments for 24 or 48 hours caused death of several root tips, chlorosis of the lower leaves, necrotic areas on some other leaves, and considerable reduction in the rate of growth during treatment.”
t0“Nicotiana tabacum L.”
Claim · model-written summary
The 1% oxygen, 20% carbon dioxide and 79% nitrogen treatment caused chlorosis of lower tobacco leaves.
- Taxon
- Nicotiana tabacum L.Nicotiana tabacumt0
- Organ / stage
- lower leavese0
- Treatment
- One percent O 2 plus 20% CO 2 plus 79% N 2 treatments for 24 or 48 hourse0
- Outcome
- chlorosis of the lower leavese0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“One percent O 2 plus 20% CO 2 plus 79% N 2 treatments for 24 or 48 hours caused death of several root tips, chlorosis of the lower leaves, necrotic areas on some other leaves, and considerable reduction in the rate of growth during treatment.”
t0“Nicotiana tabacum L.”
Claim · model-written summary
The same gas treatment caused necrotic areas on other tobacco leaves.
- Taxon
- Nicotiana tabacum L.Nicotiana tabacumt0
- Organ / stage
- leavese0
- Treatment
- One percent O 2 plus 20% CO 2 plus 79% N 2 treatments for 24 or 48 hourse0
- Outcome
- necrotic areas on some other leavese0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“One percent O 2 plus 20% CO 2 plus 79% N 2 treatments for 24 or 48 hours caused death of several root tips, chlorosis of the lower leaves, necrotic areas on some other leaves, and considerable reduction in the rate of growth during treatment.”
t0“Nicotiana tabacum L.”
Claim · model-written summary
The same gas treatment considerably reduced tobacco growth rate during treatment.
- Taxon
- Nicotiana tabacum L.Nicotiana tabacumt0
- Treatment
- One percent O 2 plus 20% CO 2 plus 79% N 2 treatments for 24 or 48 hourse0
- Outcome
- rate of growthe0
- Direction
- considerable reductione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“One percent O 2 plus 20% CO 2 plus 79% N 2 treatments for 24 or 48 hours caused death of several root tips, chlorosis of the lower leaves, necrotic areas on some other leaves, and considerable reduction in the rate of growth during treatment.”
t0“Nicotiana tabacum L.”
Claim · model-written summary
Pure nitrogen for 12 hours caused tobacco growth to cease for 60 hours.
- Taxon
- Nicotiana tabacum L.Nicotiana tabacumt0
- Treatment
- pure N 2 for 12 hourse0
- Outcome
- growth to ceasee0
- Value
- 60 hourse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Treatments with pure N 2 for 12 hours caused growth to cease for 60 hours.”
t0“Nicotiana tabacum L.”
Claim · model-written summary
Pure nitrogen for 24 hours caused death of the tobacco root system within four days.
- Taxon
- Nicotiana tabacum L.Nicotiana tabacumt0
- Treatment
- pure N 2 for 24 hourse0
- Outcome
- death of the root systeme0
- Value
- 4 dayse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Treatments with pure N 2 for 24 hours resulted in death of the root system within 4 days.”
t0“Nicotiana tabacum L.”
Claim · model-written summary
A 21% carbon dioxide treatment killed tobacco plants more quickly than pure nitrogen.
- Taxon
- Nicotiana tabacum L.Nicotiana tabacumt0
- Treatment
- 21% CO 2 for 24 hourse0
- Outcome
- killed the plantse0
- Direction
- more quicklye0
- Comparator
- pure N 2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Treatments with 21% CO 2 for 24 hours killed the plants more quickly than did pure N 2 .”
t0“Nicotiana tabacum L.”
The same questions in other papers
co2 · physiology: pigments · Nicotiana tabacum (tobacco)Positive and negative results
3 papers in the same direction as this paper · 1 in the opposite direction
- positive
- no effect
- no effect
1 paper more in this group
See all 5 papers →co2 · growth · Nicotiana tabacum (tobacco)Positive and negative results
5 papers in the same direction as this paper · 12 in the opposite direction
- positive
- positive
- positive
14 papers more in this group
See all 18 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.