ArticlePlant physiology1994
Stimulation of Nitrate and Nitrite Efflux by Ammonium in Barley (Hordeum vulgare L.) Seedlings.
Article in Plant physiology, 1994. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 7 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
7 citing papers in PubMed, 1 synthesis or guideline pooled it, 48 citations in OpenAlex.
- Plant ammonium sensitivity is associated with external pH adaptation, repertoire of nitrogen transporters, and nitrogen requirement.Journal of experimental botany · 2024Pooled it
- Apoplastic synthesis of nitric oxide by plant tissues.The Plant cell · 2004Article
- Regulation of high-affinity nitrate transporter genes and high-affinity nitrate influx by nitrogen pools in roots of barley.Plant physiology · 2000Article
- Passive nitrate transport by root plasma membrane vesicles exhibits an acidic optimal pH like the H(+)-ATPase.Plant physiology · 2000Article
- Inhibition of nitrate uptake by ammonium in barley. Analysis Of component fluxesPlant physiology · 1999Article
- Evidence for Substrate Induction of a Nitrate Efflux System in Barley Roots.Plant physiology · 1996Article
- Effect of pH and calcium on short-term NO3- fluxes in roots of barley seedlings.Plant physiology · 1995Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
The inhibitory effect of NH4+ on net NO3- uptake has been attributed to an enhancement of efflux and, recently, to an inhibition of influx. To study this controversy, we devised treatments to distinguish the effects of NH4+ on these two processes. Roots of intact barley (Hordeum vulgare L.) seedlings, uninduced or induced with NO3- or NO2-, were used. Net uptake and efflux, respectively, were determined by following the depletion and accumulation in the external solutions. In roots of both uninduced and NO2- -induced seedlings, NO3- efflux was negligible; hence, the initial uptake rates were equivalent to influx. Under these conditions, NH4+ had little effect on NO3- uptake (influx) rates by either the low- or high-Km uptake systems. In contrast, in plants preloaded with NO3-, NH4+ and its analog CH3NH3+ decreased net uptake, presumably by enhancing NO3- efflux. The stimulatory effect of NH4+ on NO3- efflux was a function of external NH4+ and internal NO3- concentration. These results were corroborated by the absence of any effect of NH4+ on NO2- uptake unless the roots were preloaded with NO2-. In this case NH4+ increased efflux and decreased net uptake. Hence, the main effect of NH4+ on net NO3- and NO2- uptake appears to be due to enhancement of efflux and not to inhibition of influx.
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.