Abstract
Azolla caroliniana was exposed to 5 °C in darkness for 1, 2, 3, 5 or 7 d and then recovered for 7 d. Plants previously chilled for 2 or 3 d exhibited higher growth rates when transferred to normal temperature than either the control plants or those previously chilled for 5 or 7 d. Increased plant growth may be related to increased contents of chlorophyll, sucrose, and reducing sugars, due to increased photosynthetic capacity. In another experiment Azolla plants were chilled at 5 °C for 7 d and then transferred for 0, 4, 8, 12, or 16 d recovery to the N-free Hoagland solution or Hoagland solution containing 5 mM KNO3. In previously chilled plants, the growth rate was decreased. In the medium supplemented with nitrogen, the growth rate was greater than in the N-free medium in both chilled and nonchilled plants. In chilled plants the decrease in growth rate may be related to the disturbance of Anabaena azollae cells where the protecting envelope of the heterocysts was deorganized. During the recovery the rate of N2-fixation increased in both chilled and nonchilled plants up to 12 d after which both rates were similar. However, during the first 4 d the rate of the nonchilled plants was approximately 4-fold that of the previously chilled plants. Nitrate reductase and nitrite reductase activities in control plants were higher than in those previously chilled for 7 d. Both activities increased in nonchilled and previously chilled plants up to 12 d then decreased. The total protein content increased up to 12 d in chilled and nonchilled plants after which it decreased. Under all treatments, the values were higher in nonchilled plants than in those previously chilled ones and were also higher in presence of N than in its absence. Thus the presence of N-source in the medium counteracts the effect of chilling injury particularly during prolonged recovery.
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Claims 13
Claim · model-written summary
Azolla caroliniana chilled for 2 or 3 d and then transferred to normal temperature grew faster than control plants.
- Taxon
- Azolla caroliniana
Azolla carolinianae0 - Treatment
- previously chilled for 2 or 3 de1
- Outcome
- growth ratese1
- Direction
- highere1
- Qualifier
- when transferred to normal temperaturee1
- Comparator
- control plantse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Azolla caroliniana”
e1“Plants previously chilled for 2 or 3 d exhibited higher growth rates when transferred to normal temperature than either the control plants or those previously chilled for 5 or 7 d”
Claim · model-written summary
Previous chilling decreased the growth rate of Azolla caroliniana.
- Taxon
- Azolla carolinianaAzolla carolinianae0
- Treatment
- previously chillede3
- Outcome
- growth ratee3
- Direction
- decreasede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Azolla caroliniana”
e3“In previously chilled plants, the growth rate was decreased”
Claim · model-written summary
Nitrogen supplementation increased the growth rate of chilled and nonchilled Azolla caroliniana relative to N-free medium.
- Taxon
- Azolla carolinianaAzolla carolinianae0
- Treatment
- medium supplemented with nitrogene4
- Outcome
- growth ratee4
- Direction
- greatere4
- Qualifier
- in both chilled and nonchilled plantse4
- Comparator
- N-free mediume4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Azolla caroliniana”
e4“In the medium supplemented with nitrogen, the growth rate was greater than in the N-free medium in both chilled and nonchilled plants”
Claim · model-written summary
In the first 4 d of recovery, the N2-fixation rate of nonchilled Azolla caroliniana was about 4-fold that of previously chilled plants.
- Taxon
- Azolla carolinianaAzolla carolinianae0
- Outcome
- the rate of the nonchilled plantse7
- Direction
- higherinferrede7
- Value
- approximately 4-folde7
- Qualifier
- during the first 4 de7
- Comparator
- previously chilled plantse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Azolla caroliniana”
e7“However, during the first 4 d the rate of the nonchilled plants was approximately 4-fold that of the previously chilled plants”
Claim · model-written summary
During recovery, N2-fixation rate increased in both chilled and nonchilled Azolla caroliniana up to 12 d, after which both rates were similar.
- Taxon
- Azolla carolinianaAzolla carolinianae0
- Outcome
- rate of N2-fixatione6
- Direction
- increasede6
- Qualifier
- up to 12 de6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Azolla caroliniana”
e6“During the recovery the rate of N2-fixation increased in both chilled and nonchilled plants up to 12 d after which both rates were similar”
Claim · model-written summary
Nitrate reductase and nitrite reductase activities in control Azolla caroliniana were higher than in plants chilled for 7 d.
- Taxon
- Azolla carolinianaAzolla carolinianae0
- Treatment
- previously chilled for 7 de1
- Outcome
- Nitrate reductase and nitrite reductase activitiese1
- Direction
- highere1
- Comparator
- control plantse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Azolla caroliniana”
e1“Nitrate reductase and nitrite reductase activities in control plants were higher than in those previously chilled for 7 d”
Claim · model-written summary
Nitrate reductase and nitrite reductase activities increased up to 12 d in chilled and nonchilled Azolla caroliniana, then decreased.
- Taxon
- Azolla carolinianaAzolla carolinianae0
- Outcome
- Nitrate reductase and nitrite reductase activitiese1
- Direction
- increasede2
- Qualifier
- up to 12 de2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Azolla caroliniana”
e1“Nitrate reductase and nitrite reductase activities in control plants were higher than in those previously chilled for 7 d”
e2“Both activities increased in nonchilled and previously chilled plants up to 12 d then decreased”
Claim · model-written summary
Total protein content of chilled and nonchilled Azolla caroliniana increased up to 12 d, then decreased.
- Taxon
- Azolla carolinianaAzolla carolinianae0
- Outcome
- total protein contente1
- Direction
- increasede1
- Qualifier
- up to 12 de1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Azolla caroliniana”
e1“The total protein content increased up to 12 d in chilled and nonchilled plants after which it decreased”
Claim · model-written summary
Under all treatments, the values were higher in nonchilled than in previously chilled Azolla caroliniana.
- Taxon
- Azolla carolinianaAzolla carolinianae0
- Treatment
- previously chilled onese1
- Outcome
- the valuese1
- Direction
- highere1
- Comparator
- nonchilled plantse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Azolla caroliniana”
e1“Under all treatments, the values were higher in nonchilled plants than in those previously chilled ones and were also higher in presence of N than in its absence”
Claim · model-written summary
Under all treatments, the values were higher with N-source than without it in Azolla caroliniana.
- Taxon
- Azolla carolinianaAzolla carolinianae0
- Treatment
- presence of Ne1
- Outcome
- the valuese1
- Direction
- highere1
- Comparator
- its absencee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Azolla caroliniana”
e1“Under all treatments, the values were higher in nonchilled plants than in those previously chilled ones and were also higher in presence of N than in its absence”
Claim · model-written summary
The N-source in the medium counteracts the effect of chilling injury on Azolla caroliniana, particularly during prolonged recovery.
- Taxon
- Azolla carolinianaAzolla carolinianae0
- Treatment
- presence of N-source in the mediume1
- Outcome
- effect of chilling injurye1
- Direction
- counteractse1
- Qualifier
- particularly during prolonged recoverye1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Azolla caroliniana”
e1“Thus the presence of N-source in the medium counteracts the effect of chilling injury particularly during prolonged recovery”
Claim · model-written summary
Increased plant growth in Azolla caroliniana may be related to increased chlorophyll, sucrose and reducing sugar contents from increased photosynthetic capacity.
- Taxon
- Azolla carolinianaAzolla carolinianae0
- Outcome
- plant growthe2
- Qualifier
- increased contents of chlorophyll, sucrose, and reducing sugarse2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Azolla caroliniana”
e2“Increased plant growth may be related to increased contents of chlorophyll, sucrose, and reducing sugars, due to increased photosynthetic capacity”
Claim · model-written summary
The decrease in growth rate of chilled Azolla caroliniana may be related to disturbance of Anabaena azollae cells.
- Taxon
- Azolla carolinianaAzolla carolinianae0
- Interactor
- Anabaena azollae
Trichormus azollaee5symbiont - Outcome
- growth ratee5
- Qualifier
- disturbance of Anabaena azollae cellse5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Azolla caroliniana”
e5“In chilled plants the decrease in growth rate may be related to the disturbance of Anabaena azollae cells where the protecting envelope of the heterocysts was deorganized”
The same questions in other papers
nitrogen · growth · Azolla caroliniana (mosquito fern)Results agree
1 paper in the same direction as this paper
- positive
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.