Abstract
In the Sahelian zone, low soil N could be as limiting as drought in pearl millet production. Although growth and crop productivity depend on several biochemical reactions in which the nitrogen metabolism plays a great role, there is little information available on how N uptake and key enzymes, nitrate reductase and glutamine synthetase, are affected by nitrogen and water interaction in millet. For this purpose, the millet variety cv. Souna III was grown in the field during the dry season under three levels of nitrogen fertilization (NO = 0.0, N1 = 17.13, and N2 = 68.50 kg N ha-1) and different water regimes (well-watered and water-stressed) in a split-plot experimental design. Irrigation was stopped for water-stressed plants during tillering, and the grain formation and filling phases, thereby giving rise to two water deficit cycles. A major quantity of mobilized N (79-100%) was taken up before flowering in all N treatments. Nitrogen uptake declined significantly only during the second water deficit cycle. During the first water deficit cycle, aboveground biomass was reduced and the maintenance of the N uptake resulted in increased N and nitrate concentrations. The water deficit reduced nitrate reductase activity jn all treatments and the effect was greater under high N. The increase in nitrate concentration under water deficit conditions showed that the reduction in nitrate reductase activity was probably not due to limiting nitrates. Glutamine synthetase activity was higher under the low N treatments, N1 and N0, showing the absence of a stimulating effect of glutamine synthetase activity by nitrate or ammonium. These results are discussed on the basis of their effect on grain N and grain yield.
Abstract from the paper’s OpenAlex record; open copy licensed other-oa. 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 9
Claim · model-written summary
Most mobilized N uptake occurred before flowering in all N treatments.
- Taxon
- Pearl Millet
Cenchrus americanust0 - Organ / stage
- before floweringe0
- Outcome
- mobilized Ne0
- Value
- 79-100%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A major quantity of mobilized N (79-100%) was taken up before flowering in all N treatments.”
t0“Pearl Millet”
Claim · model-written summary
Nitrogen uptake declined significantly only in the second water deficit cycle.
- Taxon
- Pearl MilletCenchrus americanust0
- Treatment
- second water deficit cyclee0
- Outcome
- Nitrogen uptakee0
- Direction
- declinede0
- Qualifier
- only during the second water deficit cyclee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nitrogen uptake declined significantly only during the second water deficit cycle.”
t0“Pearl Millet”
Claim · model-written summary
Aboveground biomass fell during the first water deficit cycle.
- Taxon
- Pearl MilletCenchrus americanust0
- Treatment
- first water deficit cyclee0
- Outcome
- aboveground biomasse0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“During the first water deficit cycle, aboveground biomass was reduced”
t0“Pearl Millet”
Claim · model-written summary
Maintained nitrogen uptake in the first deficit cycle resulted in increased N concentration.
- Taxon
- Pearl MilletCenchrus americanust0
- Outcome
- Ne0
- Direction
- increasede0
- Qualifier
- maintenance of the N uptakee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the maintenance of the N uptake resulted in increased N and nitrate concentrations”
t0“Pearl Millet”
Claim · model-written summary
Maintained nitrogen uptake in the first deficit cycle resulted in increased nitrate concentration.
- Taxon
- Pearl MilletCenchrus americanust0
- Outcome
- nitrate concentrationse0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the maintenance of the N uptake resulted in increased N and nitrate concentrations”
t0“Pearl Millet”
Claim · model-written summary
Water deficit reduced nitrate reductase activity in all treatments, especially at high N.
- Taxon
- Pearl MilletCenchrus americanust0
- Treatment
- water deficite0
- Gene
- nitrate reductasee0
- Outcome
- nitrate reductase activitye0
- Direction
- reducede0
- Qualifier
- greater under high Ne0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The water deficit reduced nitrate reductase activity jn all treatments and the effect was greater under high N.”
t0“Pearl Millet”
Claim · model-written summary
The authors infer that reduced nitrate reductase activity under deficit was probably not caused by limited nitrate.
- Taxon
- Pearl MilletCenchrus americanust0
- Gene
- nitrate reductasee0
- Outcome
- reduction in nitrate reductase activitye0
- Qualifier
- probably not due to limiting nitratese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The increase in nitrate concentration under water deficit conditions showed that the reduction in nitrate reductase activity was probably not due to limiting nitrates.”
t0“Pearl Millet”
Claim · model-written summary
Glutamine synthetase activity was higher at low N treatments N1 and N0.
- Taxon
- Pearl MilletCenchrus americanust0
- Treatment
- low N treatments, N1 and N0e0
- Gene
- Glutamine synthetasee0
- Outcome
- Glutamine synthetase activitye0
- Direction
- highere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Glutamine synthetase activity was higher under the low N treatments, N1 and N0”
t0“Pearl Millet”
Claim · model-written summary
The authors found no stimulation of glutamine synthetase activity by nitrate or ammonium.
- Taxon
- Pearl MilletCenchrus americanust0
- Gene
- glutamine synthetasee0
- Outcome
- absence of a stimulating effect of glutamine synthetase activitye0
- Qualifier
- by nitrate or ammoniume0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“showing the absence of a stimulating effect of glutamine synthetase activity by nitrate or ammonium”
t0“Pearl Millet”
The same questions in other papers
drought · nutrient: content · Cenchrus americanus (pearl millet)Positive and negative results
1 paper in the same direction as this paper · 2 in the opposite direction
- positive
- positive
- no effect
drought · growth · Cenchrus americanus (pearl millet)Positive and negative results
10 papers in the same direction as this paper · 5 in the opposite direction
- positive
- positive
- positive
12 papers more in this group
See all 16 papers →drought · physiology: enzyme activity · Cenchrus americanus (pearl millet)Results agree
1 paper in the same direction as this paper
- negative
nitrogen · physiology: enzyme activity · Cenchrus americanus (pearl millet)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.