Abstract
Abstract Nitrogen uptake by rooted cuttings of sweet potato [ Ipomoea batatas (L.) Lam.] has not been studied extensively although “slips” (rooted sprouts) are the normal plant part used in commercial propagation. Experiments with rooted cuttings of sweet potato, cultivar ‘Jewell’, were conducted in solution culture to investigate the effects of ambient acidity and the presence and concentration effects of ammonium and nitrate on rates of nitrate and ammonium uptake. Plant stem cuttings were rooted in Hoagland's solution (plus or minus nitrate) then transferred to 980 ml containers of experimental solutions. In experiment I rates of N uptake from 0.1 mM NH 4 NO 3 were measured at pH of 4.5, 5.5, and 6.5. In experiment II rates of N uptake were measured from 0.1 m M solutions with and without the presence of the ammonium in the case of nitrate uptake and vice versa. In experiment III nitrate uptake was measured from 0.1 m M nitrate without ammonium and in the presence of 0.1 m M and 1 m M ammonium. Solutions were sampled periodically and analyzed for nitrate, ammonium, and K. Nitrate uptake rate was decreased by increasing ambient pH while ammonium uptake rate was increased. Presence of ambient ammonium at equimolar concentration decreased rate of nitrate uptake ,∼30% at pH 5.5. However, a tenfold increase in ammonium concentration did not further reduce rate of nitrate uptake although rate of ammonium uptake was doubled. Presence of equimolar nitrate had no effect on rate of ammonium uptake at 0.1 m M ammonium. Efflux of K to initially K‐free solutions was increased by ambient ammonium, but a transition from K efflux to influx occurred without a consistent change in rates of ammonium or nitrate uptake. A suggestion is made that two components of nitrate uptake by sweet potato roots exist, one of which is assumed to be associated with nitrate reductase and inhibited by ammonium.
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Claims 9
Claim · model-written summary
Increasing pH decreased nitrate uptake.
- Taxon
- sweet potato
_Flower.jpg?width=60)
Ipomoea batatast0 - Treatment
- increasing ambient pHe0
- Outcome
- Nitrate uptake ratee0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_Flower.jpg?width=500)
Verbatim
e0“Nitrate uptake rate was decreased by increasing ambient pH”
t0“Sweet Potato”
Claim · model-written summary
Increasing pH increased ammonium uptake.
- Taxon
- sweet potatoIpomoea batatast0
- Outcome
- ammonium uptake ratee0
- Direction
- increasede0
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“while ammonium uptake rate was increased”
t0“Sweet Potato”
Claim · model-written summary
Equimolar ammonium reduced nitrate uptake about 30% at pH 5.5.
- Taxon
- sweet potatoIpomoea batatast0
- Treatment
- ambient ammonium at equimolar concentratione0
- Outcome
- rate of nitrate uptakee0
- Direction
- decreasede0
- Value
- ∼30%e0
- Qualifier
- at pH 5.5e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Presence of ambient ammonium at equimolar concentration decreased rate of nitrate uptake ,∼30% at pH 5.5”
t0“Sweet Potato”
Claim · model-written summary
Tenfold higher ammonium did not further reduce nitrate uptake.
- Taxon
- sweet potatoIpomoea batatast0
- Treatment
- tenfold increase in ammonium concentratione0
- Outcome
- rate of nitrate uptakee0
- Direction
- did not further reducee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a tenfold increase in ammonium concentration did not further reduce rate of nitrate uptake”
t0“Sweet Potato”
Claim · model-written summary
Tenfold higher ammonium doubled ammonium uptake.
- Taxon
- sweet potatoIpomoea batatast0
- Outcome
- rate of ammonium uptakee0
- Direction
- doublede0
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“rate of ammonium uptake was doubled”
t0“Sweet Potato”
Claim · model-written summary
Equimolar nitrate had no effect on ammonium uptake at 0.1 m M ammonium.
- Taxon
- sweet potatoIpomoea batatast0
- Treatment
- equimolar nitratee0
- Outcome
- rate of ammonium uptakee0
- Direction
- no effecte0
- Qualifier
- at 0.1 m M ammoniume0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Presence of equimolar nitrate had no effect on rate of ammonium uptake at 0.1 m M ammonium”
t0“Sweet Potato”
Claim · model-written summary
Ambient ammonium increased potassium efflux.
- Taxon
- sweet potatoIpomoea batatast0
- Treatment
- ambient ammoniume0
- Outcome
- Efflux of Ke0
- Direction
- increasede0
- Qualifier
- initially K‐free solutionse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Efflux of K to initially K‐free solutions was increased by ambient ammonium”
t0“Sweet Potato”
Claim · model-written summary
Potassium transport shifted from efflux to influx without consistent change in nitrogen uptake.
- Taxon
- sweet potatoIpomoea batatast0
- Outcome
- transition from K efflux to influxe0
- Qualifier
- without a consistent change in rates of ammonium or nitrate uptakee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a transition from K efflux to influx occurred without a consistent change in rates of ammonium or nitrate uptake”
t0“Sweet Potato”
Claim · model-written summary
Authors proposed two nitrate uptake components, one linked to nitrate reductase and inhibited by ammonium.
- Taxon
- sweet potatoIpomoea batatase0
- Organ / stage
- rootse0
- Gene
- nitrate reductasee0
- Outcome
- nitrate uptakee0
- Qualifier
- inhibited by ammoniume0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“two components of nitrate uptake by sweet potato roots exist, one of which is assumed to be associated with nitrate reductase and inhibited by ammonium”
The same questions in other papers
nitrogen · nutrient: content · Ipomoea batatas (sweet potato)Positive and negative results
3 papers in the same direction as this paper · 5 in the opposite direction
- positive
- positive
- positive
5 papers more in this group
See all 9 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.