Claim · model-written summary
Adding 20% oxygen (v/v) decreased acetylene reduction by 30 to 40%.
- Treatment
- addition of oxygen, 20% volume per volumee7
- Outcome
- rate of acetylene reductione7
- Direction
- decreasee7
- Value
- 30 to 40%e7
Not reportedMaterialGeneCompoundOrgan / stageInteractorInteractor roleSecond interactorSecond interactor roleComparatorSettingQualifier
Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Verbatim
e3“The growth of Azolla for 35 days with nitrate or urea as a nitrogen source decreased the rate of acetylene reduction approximately 30% compared to controls grown on nitrogen”
e7“The addition of oxygen, 20% volume per volume, resulted in a 30 to 40% decrease in the rate of acetylene reduction”
Title
The Azolla, Anabaena azollae Relationship
Gerald A. Peters; Berger C. Mayne PLANT PHYSIOLOGY 1974. doi:10.1104/pp.53.6.820
Other claims from this paper (11)
- Observation Acetylene reduction by Azolla caroliniana is light-dependent and saturated at approximately 450 foot candles.
- Observation The maximum acetylene reduction rate of Azolla was 60 nmoles/mg chlorophyll per minute.
- Observation Acetylene reduction rates of 25 to 30 nmoles/mg chlorophyll per minute were more common.
- Intervention effect Growing Azolla for 35 days on nitrate or urea decreased acetylene reduction by approximately 30% compared with nitrogen-grown controls.
- Intervention effect Prolonged growth (6-7 months) on nitrate or urea decreased the rate of acetylene reduction by 90%.
- Intervention effect Inhibition of acetylene reduction by 3 (3,4-dichlorophenol) 1,1-dimethylurea was not pronounced until the Azolla reserves were depleted.
- Intervention effect The herbicide 3 (3,4-dichlorophenol) 1,1-dimethylurea inhibited oxygen evolution by 75% within 10 minutes.
- Observation Aerobic dark acetylene reduction was 10 to 30% of the aerobic rate in the light.
- Intervention effect Acetylene reduction activity of Azolla was absent in fronds freed of the symbiotic alga and present in isolated Anabaena azollae.
- Mechanism The alga, not the fern tissue, is the agent of acetylene reduction.
- Mechanism Considerable transport of metabolites between Azolla and its blue-green alga is suggested.