scholarly journals Plant nitrogen uptake and assimilation: regulation of cellular pH homeostasis

2020 ◽  
Vol 71 (15) ◽  
pp. 4380-4392 ◽  
Author(s):  
Huimin Feng ◽  
Xiaorong Fan ◽  
Anthony J Miller ◽  
Guohua Xu
Keyword(s):  
Intracellular Ph ◽  
Ph Regulation ◽  
N Uptake ◽  
Plant Cells ◽  
Proton Pumps ◽  
Ph Homeostasis ◽  
Long Distance ◽  
N Source ◽  
N Assimilation ◽  
In Cells

Abstract The enzymatic controlled metabolic processes in cells occur at their optimized pH ranges, therefore cellular pH homeostasis is fundamental for life. In plants, the nitrogen (N) source for uptake and assimilation, mainly in the forms of nitrate (NO3–) and ammonium (NH4+) quantitatively dominates the anion and cation equilibrium and the pH balance in cells. Here we review ionic and pH homeostasis in plant cells and regulation by N source from the rhizosphere to extra- and intracellular pH regulation for short- and long-distance N distribution and during N assimilation. In the process of N transport across membranes for uptake and compartmentation, both proton pumps and proton-coupled N transporters are essential, and their proton-binding sites may sense changes of apoplastic or intracellular pH. In addition, during N assimilation, carbon skeletons are required to synthesize amino acids, thus the combination of NO3– or NH4+ transport and assimilation results in different net charge and numbers of protons in plant cells. Efficient maintenance of N-controlled cellular pH homeostasis may improve N uptake and use efficiency, as well as enhance the resistance to abiotic stresses.

scholarly journals pH homeostasis in human lymphocytes: modulation by ions and mitogen.

1984 ◽  
Vol 98 (3) ◽  
pp. 885-893 ◽  
Author(s):  
C Deutsch ◽  
J S Taylor ◽  
M Price
Keyword(s):  
Intracellular Ph ◽  
Proliferative Response ◽  
Prolonged Exposure ◽  
Ph Regulation ◽  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
Peripheral Blood Lymphocytes ◽  
Ph Homeostasis ◽  
Normal Medium ◽  
Ph Range

Quiescent human peripheral blood lymphocytes have been shown to maintain a relatively constant intracellular pH of 7.0-7.2 over an extracellular pH range of 6.9-7.4. Two methods of measuring intracellular pH were used in these studies, 19F nuclear magnetic resonance and [14C]5,5-dimethyloxazolidine-2,4-dione (DMO) equilibrium distributions. When ATP levels were decreased in these cells, actively maintained pH regulation was abolished and cells exhibited a constant pH gradient of 0.2 pH unit (acid inside relative to outside). Possible mechanisms for pH regulation are discussed. The effects of the Na+ and K+ composition of the medium on pH regulation showed no correlation with their effects on mitogen-induced proliferative response, which we have previously determined (Deutsch, C., and M. Price, 1982, J. Cell. Physiol., 111:73-79). In low-Na+ mannitol medium, pH regulation was similar to that observed for lymphocytes in normal medium, whereas mitogen-induced proliferation was severely inhibited in low-Na+ mannitol. In contrast, high-K+, low Na+ medium caused loss of pH homeostasis, whereas it restored the proliferative response. Loss of pH homeostasis was also observed on prolonged exposure of lymphocytes to mitogen (greater than 6 h in culture). However, mitogen stimulation led to little or no change in intracellular pH in the first few hours of cell culture. Therefore, a shift in intracellular pH is not a necessary or general event in mitogen-stimulated proliferation of lymphocytes.

scholarly journals Regulation of intracellular pH during oocyte growth and maturation in mammals

Reproduction ◽  
2009 ◽  
Vol 138 (4) ◽  
pp. 619-627 ◽  
Author(s):  
Greg FitzHarris ◽  
Jay M Baltz
Keyword(s):  
Intracellular Ph ◽  
Ph Regulation ◽  
Cell Types ◽  
Mammalian Development ◽  
Ph Homeostasis ◽  
Oocyte Growth ◽  
Homeostatic Process ◽  
Mapk Signalling ◽  
Recent Developments ◽  
Early Mammalian Development

Regulation of intracellular pH (pHi) is a fundamental homeostatic process essential for the survival and proliferation of virtually all cell types. The mammalian preimplantation embryo, for example, possesses Na+/H+and HCO3−/Cl−exchangers that robustly regulate against acidosis and alkalosis respectively. Inhibition of these transporters prevents pH corrections and, perhaps unsurprisingly, leads to impaired embryogenesis. However, recent studies have revealed that the role and regulation of pHiis somewhat more complex in the case of the developing and maturing oocyte. Small meiotically incompetent growing oocytes are apparently incapable of regulating their own pHi, and instead rely upon the surrounding granulosa cells to correct ooplasmic pH, until such a time that the oocyte has developed the capacity to regulate its own pHi. Later, during meiotic maturation, pHi-regulating activities that were developed during growth are inactivated, apparently under the control of MAPK signalling, until the oocyte is successfully fertilized. Here, we will discuss pH homeostasis in early mammalian development, focussing on recent developments highlighting the unusual and unexpected scenario of pH regulation during oocyte growth and maturation.

Mechanisms of intracellular pH regulation during postischemic reperfusion of diabetic rat hearts

Diabetes ◽  
1995 ◽  
Vol 44 (2) ◽  
pp. 196-202 ◽  
Author(s):  
N. Khandoudi ◽  
M. Bernard ◽  
P. Cozzone ◽  
D. Feuvray
Keyword(s):  
Intracellular Ph ◽  
Ph Regulation ◽  
Diabetic Rat ◽  
Intracellular Ph Regulation ◽  
Postischemic Reperfusion ◽  
Rat Hearts

scholarly journals Biochar and urease inhibitor mitigate NH3 and N2O emissions and improve wheat yield in a urea fertilized alkaline soil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Khadim Dawar ◽  
Shah Fahad ◽  
M. M. R. Jahangir ◽  
Iqbal Munir ◽  
Syed Sartaj Alam ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Grain Yield ◽  
Block Design ◽  
N Uptake ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
Urease Inhibitor ◽  
Alkaline Soil ◽  
Total N ◽  
N Assimilation

AbstractIn this study, we explored the role of biochar (BC) and/or urease inhibitor (UI) in mitigating ammonia (NH3) and nitrous oxide (N2O) discharge from urea fertilized wheat cultivated fields in Pakistan (34.01°N, 71.71°E). The experiment included five treatments [control, urea (150 kg N ha−1), BC (10 Mg ha−1), urea + BC and urea + BC + UI (1 L ton−1)], which were all repeated four times and were carried out in a randomized complete block design. Urea supplementation along with BC and BC + UI reduced soil NH3 emissions by 27% and 69%, respectively, compared to sole urea application. Nitrous oxide emissions from urea fertilized plots were also reduced by 24% and 53% applying BC and BC + UI, respectively, compared to urea alone. Application of BC with urea improved the grain yield, shoot biomass, and total N uptake of wheat by 13%, 24%, and 12%, respectively, compared to urea alone. Moreover, UI further promoted biomass and grain yield, and N assimilation in wheat by 38%, 22% and 27%, respectively, over sole urea application. In conclusion, application of BC and/or UI can mitigate NH3 and N2O emissions from urea fertilized soil, improve N use efficiency (NUE) and overall crop productivity.

CPX, a selective A1-adenosine-receptor antagonist, regulates intracellular pH in cystic fibrosis cells

1995 ◽  
Vol 269 (1) ◽  
pp. C226-C233 ◽  
Author(s):  
V. Casavola ◽  
R. J. Turner ◽  
C. Guay-Broder ◽  
K. A. Jacobson ◽  
O. Eidelman ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Receptor Antagonist ◽  
Intracellular Ph ◽  
Adenosine Receptor ◽  
Ph Regulation ◽  
Cystic Fibrosis Transmembrane Regulator ◽  
Wild Type ◽  
A1 Adenosine Receptor ◽  
Adenosine Receptor Antagonist ◽  
Cystic Fibrosis Transmembrane

The selective A1-adenosine-receptor antagonist, 8-cyclopentyl-1,3-dipropylxanthine (CPX), has been reported to activate Cl- efflux from cystic fibrosis cells, such as pancreatic CFPAC-1 and lung IB3 cells bearing the cystic fibrosis transmembrane regulator(delta F508) mutation, but has little effect on the same process in cells repaired by transfection with wild-type cystic fibrosis transmembrane regulator (O. Eidelman, C. Guay-Broder, P. J. M. van Galen, K. A. Jacobson, C. Fox, R. J. Turner, Z. I. Cabantchik, and H. B. Pollard. Proc. Natl. Acad. Sci. USA 89: 5562-5566, 1992). We report here that CPX downregulates Na+/H+ exchange activity in CFPAC-1 cells but has a much smaller effect on cells repaired with the wild-type gene. CPX also mildly decreases resting intracellular pH. In CFPAC-1 cells, this downregulation is dependent on the presence of adenosine, since pretreatment of the cells with adenosine deaminase blocks the CPX effect. We also show that, by contrast, CPX action on these cells does not lead to alterations in intracellular free Ca2+ concentration. We conclude that CPX affects pH regulation in CFPAC-1 cells, probably by antagonizing the tonic action of endogenous adenosine.

scholarly journals Activation of vacuolar-type proton pumps by protein kinase C. Role in neutrophil pH regulation

1992 ◽  
Vol 267 (32) ◽  
pp. 22740-22746
Author(s):  
A Nanda ◽  
A Gukovskaya ◽  
J Tseng ◽  
S Grinstein
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Ph Regulation ◽  
Proton Pumps ◽  
Kinase C
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