Abstract
Anaerobic (microaerophilic) acetylene reduction by Azolla caroliniana Willd. was dependent on light and saturated at approximately 450 foot candles. Maximum rates of acetylene reduction were 60 nmoles/mg chlorophyll minute. However, rates of 25 to 30 nmoles/mg chlorophyll minute were more common.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. Prolonged growth on nitrate or urea (6-7 months) resulted in a 90% decrease in the rate of acetylene reduction.The inhibition of acetylene reduction by 3 (3,4-dichlorophenol) 1,1-dimethylurea (12 muM) was not pronounced until the Azolla became depleted of the reserves formed during photosynthesis. The interval required for this depletion was dependent upon pretreatment and varied from 2 to more than 12 hours. Oxygen evolution was inhibited 75% in 10 minutes by the same concentration of 3 (3,4-dichlorophenol) 1,1-dimethylurea.The addition of oxygen, 20% volume per volume, resulted in a 30 to 40% decrease in the rate of acetylene reduction and the onsetof 3(3,4-dichlorophenol) 1,1-dimethylurea inhibition was more rapid then under microaerophilic conditions. The aerobic dark reduction of acetylene was from 10 to 30% of the rate of aerobic reduction in the light.Acetylene reduction activity was absent in fronds freed ofthe symbiotic algae and present in isolated Anabaena azollae. This study shows that the alga is the agent of acetylene reduction and suggests that there is considerable transport of metabolites between the fern and the blue-green alga.
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
Acetylene reduction by Azolla caroliniana is light-dependent and saturated at approximately 450 foot candles.
- Taxon
- Azolla caroliniana
Azolla carolinianae0 - Treatment
- lighte0
- Outcome
- acetylene reductione0
- Value
- approximately 450 foot candlese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Anaerobic (microaerophilic) acetylene reduction by Azolla caroliniana Willd. was dependent on light and saturated at approximately 450 foot candles”
Claim · model-written summary
The maximum acetylene reduction rate of Azolla was 60 nmoles/mg chlorophyll per minute.
- Taxon
- Azolla carolinianaAzolla carolinianae0
- Outcome
- rates of acetylene reductione1
- Value
- 60 nmoles/mg chlorophyll minutee1
- Qualifier
- Maximume1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Anaerobic (microaerophilic) acetylene reduction by Azolla caroliniana Willd. was dependent on light and saturated at approximately 450 foot candles”
e1“Maximum rates of acetylene reduction were 60 nmoles/mg chlorophyll minute”
Claim · model-written summary
Acetylene reduction rates of 25 to 30 nmoles/mg chlorophyll per minute were more common.
- Taxon
- Azolla carolinianaAzolla carolinianae0
- Outcome
- rates of acetylene reductione1
- Value
- 25 to 30 nmoles/mg chlorophyll minutee2
- Qualifier
- more commone2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Anaerobic (microaerophilic) acetylene reduction by Azolla caroliniana Willd. was dependent on light and saturated at approximately 450 foot candles”
e1“Maximum rates of acetylene reduction were 60 nmoles/mg chlorophyll minute”
e2“rates of 25 to 30 nmoles/mg chlorophyll minute were more common”
Claim · model-written summary
Growing Azolla for 35 days on nitrate or urea decreased acetylene reduction by approximately 30% compared with nitrogen-grown controls.
- Treatment
- nitrate or urea as a nitrogen sourcee3
- Outcome
- rate of acetylene reductione3
- Direction
- decreasede3
- Value
- approximately 30%e3
- Qualifier
- for 35 dayse3
- Comparator
- controls grown on nitrogene3
AzollaOrganisms 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”
Claim · model-written summary
Prolonged growth (6-7 months) on nitrate or urea decreased the rate of acetylene reduction by 90%.
- Treatment
- Prolonged growth on nitrate or ureae4
- Outcome
- rate of acetylene reductione4
- Direction
- decreasee4
- Value
- 90%e4
- Qualifier
- 6-7 monthse4
Not reportedComparator
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”
e4“Prolonged growth on nitrate or urea (6-7 months) resulted in a 90% decrease in the rate of acetylene reduction”
Claim · model-written summary
Inhibition of acetylene reduction by 3 (3,4-dichlorophenol) 1,1-dimethylurea was not pronounced until the Azolla reserves were depleted.
- Treatment
- 3 (3,4-dichlorophenol) 1,1-dimethylureae5
- Outcome
- acetylene reductione5
- Qualifier
- not pronounced untile5
Not reportedComparatorDirection
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”
e5“The inhibition of acetylene reduction by 3 (3,4-dichlorophenol) 1,1-dimethylurea (12 muM) was not pronounced until the Azolla became depleted of the reserves formed during photosynthesis”
Claim · model-written summary
The herbicide 3 (3,4-dichlorophenol) 1,1-dimethylurea inhibited oxygen evolution by 75% within 10 minutes.
- Treatment
- 3 (3,4-dichlorophenol) 1,1-dimethylureae6
- Outcome
- Oxygen evolutione6
- Direction
- inhibitede6
- Value
- 75%e6
- Qualifier
- in 10 minutese6
Not reportedComparator
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”
e6“Oxygen evolution was inhibited 75% in 10 minutes by the same concentration of 3 (3,4-dichlorophenol) 1,1-dimethylurea”
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 reportedComparator
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”
Claim · model-written summary
Aerobic dark acetylene reduction was 10 to 30% of the aerobic rate in the light.
- Outcome
- aerobic dark reduction of acetylenee1
- Value
- from 10 to 30%e1
- Comparator
- aerobic reduction in the lighte1
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”
e1“The aerobic dark reduction of acetylene was from 10 to 30% of the rate of aerobic reduction in the light”
Claim · model-written summary
Acetylene reduction activity of Azolla was absent in fronds freed of the symbiotic alga and present in isolated Anabaena azollae.
- Treatment
- fronds freed ofthe symbiotic algaee4
- Interactor
- Anabaena azollae
Trichormus azollaee4symbiont - Outcome
- Acetylene reduction activitye4
- Comparator
- isolated Anabaena azollaee4
Not reportedDirection
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”
e4“Acetylene reduction activity was absent in fronds freed ofthe symbiotic algae and present in isolated Anabaena azollae”
Claim · model-written summary
The alga, not the fern tissue, is the agent of acetylene reduction.
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”
e4“This study shows that the alga is the agent of acetylene reduction and suggests that there is considerable transport of metabolites between the fern and the blue-green alga”
Claim · model-written summary
Considerable transport of metabolites between Azolla and its blue-green alga is suggested.
- Taxon
- Azolla carolinianaAzolla carolinianae0
- Interactor
- blue-green algae4symbiont
- Outcome
- transport of metabolitese4
- Qualifier
- considerable transport of metabolitese4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Anaerobic (microaerophilic) acetylene reduction by Azolla caroliniana Willd. was dependent on light and saturated at approximately 450 foot candles”
e4“This study shows that the alga is the agent of acetylene reduction and suggests that there is considerable transport of metabolites between the fern and the blue-green alga”