Even if urea and nitrate are the two major nitrogen (N) forms applied as fertilizers in agriculture and occur concomitantly in soils, the reciprocal influence of these two N sources on the mechanisms of their acquisition are poorly understood. Therefore, molecular and physiological aspects of urea and nitrate uptake were investigated in maize (Zea mays), a crop plant consuming high amounts of N. In roots, the urea uptake was stimulated by the presence of urea in the external solution, indicating the presence of an inducible transport system. On the other hand the presence of nitrate depressed the induction of urea uptake and, at the same time, the induction of nitrate uptake was depressed by the presence of urea. The expression of about 60,000 transcripts of maize in roots was monitored by microarray analyses and the transcriptional patterns of those genes involved in nitrogen acquisition were analysed by real-time RT-PCR. In comparison to the treatment without added N, the exposure of maize roots to urea modulated the expression of only very few genes, such as asparagine synthase. On the other hand, the concomitant presence of urea and nitrate enhanced the overexpression of genes involved in nitrate transport (NRT2), assimilation (nitrate and nitrite reductase, glutamine synthetase 2) and determined a specific response of 41 transcripts, including glutamine synthetase 1-5, GOGAT, shikimate kinase and arogenate dehydrogenase. Based also on the real-time RT-PCR analysis, the transcriptional modulation induced by both sources might determine an increase in N-metabolism promoting a more efficient assimilation of taken-up nitrogen.
This research output has an Altmetric Attention Score of 6. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 28 January 2025.
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#9,293,012
of 34,410,798 outputs
Outputs from Plant & Cell Physiology
#1,161
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Outputs of similar age
#93,693
of 396,474 outputs
Outputs of similar age from Plant & Cell Physiology
#16
of 61 outputs
Altmetric has tracked 34,410,798 research outputs across all sources so far. This one has received more attention than most of these and is in the 72nd percentile.
So far Altmetric has tracked 3,732 research outputs from this source. They typically receive a little more attention than average, with a mean Attention Score of 5.5. This one has gotten more attention than average, scoring higher than 68% of its peers.
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We're also able to compare this research output to 61 others from the same source and published within six weeks on either side of this one. This one has gotten more attention than average, scoring higher than 73% of its contemporaries.
