Elevation of cytosolic Ca2+ in response to energy deficiency in plants: the general mechanism of adaptation to low oxygen stress

2018 ◽  
Vol 475 (8) ◽  
pp. 1411-1425 ◽  
Author(s):  
Abir U. Igamberdiev ◽  
Robert D. Hill
Keyword(s):  
Nitric Oxide ◽  
Ph Regulation ◽  
Oxygen Deficiency ◽  
Pyruvate Decarboxylase ◽  
General Mechanism ◽  
Low Oxygen ◽  
Energy Deficiency ◽  
Cell Compartments ◽  
Cytosolic Side ◽  
Nitric Oxide Cycle

Ca2+ can be released from cell compartments to the cytosol during stress conditions. We discuss here the causes of Ca2+ release under conditions of ATP concentration decline that result in the suppression of ATPases and activation of calcium ion channels. The main signaling and metabolic consequences of Ca2+ release are considered for stressed plant cells. The signaling function includes generation and spreading of calcium waves, while the metabolic function results in the activation of particular enzymes and genes. Ca2+ is involved in the activation of glutamate decarboxylase, initiating the γ-aminobutyric acid shunt and triggering the formation of alanine, processes which play a role, in particular, in pH regulation. Ca2+ activates the transcription of several genes, e.g. of plant hemoglobin (phytoglobin, Pgb) which scavenges nitric oxide and regulates redox and energy balance through the Pgb–nitric oxide cycle. This cycle involves NADH and NADPH oxidation from the cytosolic side of mitochondria, in which Ca2+- and low pH-activated external NADH and NADPH dehydrogenases participate. Ca2+ can also activate the genes of alcohol dehydrogenase and pyruvate decarboxylase stimulating hypoxic fermentation. It is concluded that calcium is a primary factor that causes the metabolic shift under conditions of oxygen deficiency.

Tolerance of roots to low oxygen: ‘Anoxic’ cores, the phytoglobin-nitric oxide cycle, and energy or oxygen sensing

2019 ◽  
Vol 239 ◽  
pp. 92-108 ◽  
Author(s):  
William Armstrong ◽  
Peter M. Beckett ◽  
Timothy D. Colmer ◽  
Timothy L. Setter ◽  
Hank Greenway
Keyword(s):  
Nitric Oxide ◽  
Oxygen Sensing ◽  
Low Oxygen ◽  
Nitric Oxide Cycle

Sensitivity of malaria parasites to nitric oxide at low oxygen tensions

The Lancet ◽  
1998 ◽  
Vol 351 (9116) ◽  
pp. 1630 ◽  
Author(s):  
AW Taylor-Robinson ◽  
M Looker
Keyword(s):  
Nitric Oxide ◽  
Low Oxygen ◽  
Malaria Parasites ◽  
Oxygen Tensions

scholarly journals Decreased glutamine synthetase, increased citrulline–nitric oxide cycle activities, and oxidative stress in different regions of brain in epilepsy rat model

2010 ◽  
Vol 67 (1) ◽  
pp. 105-113 ◽  
Author(s):  
Mummedy Swamy ◽  
Wan Roslina Wan Yusof ◽  
K. N. S. Sirajudeen ◽  
Zulkarnain Mustapha ◽  
Chandran Govindasamy
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Glutamine Synthetase ◽  
Rat Model ◽  
Nitric Oxide Cycle ◽  
And Oxidative Stress

scholarly journals Effects of Low-oxygen Atmosphere on Ethanolic Fermentation in Fresh-cut Carrots

1997 ◽  
Vol 122 (1) ◽  
pp. 107-111 ◽  
Author(s):  
Hisashi Kato-Noguchi ◽  
Alley E. Watada
Keyword(s):  
Alcohol Dehydrogenase ◽  
Daucus Carota ◽  
Continuous Flow ◽  
Pyruvate Decarboxylase ◽  
Oxygen Atmosphere ◽  
Low Oxygen ◽  
Ethanolic Fermentation ◽  
Fresh Cut ◽  
Fermentation Metabolism

Carrot (Daucus carota L.) root shreds were stored under a continuous flow of 0.5% and 2% O2 (balance N2) or in air for 7 days at 5 and 15 °C to study the regulation of ethanolic fermentation metabolism. Low-O2 atmospheres of 0.5% and 2% caused increases in ethanol and acetaldehyde concentrations and the activities of alcohol dehydrogenase (ADH) and pyruvate decarboxylase (PDC) compared to air. By day 3, ethanol increased 38-, 25-, 13-, and 9.5-fold; acetaldehyde increased 20-, 13-, 7.7-, and 5.6-fold; ADH increased 7.6-, 6.3-, 3.8-, and 2.7-fold; and PDC increased 4.2-, 3.9-, 2.3-, and 2.2-fold in samples at 0.5% O2 at 15 or 5 °C and at 2% O2 at 15 or 5 °C, respectively, compared with corresponding samples in air. These results indicate that ethanolic fermentation was accelerated more in the 0.5% than in the 2% O2 atmosphere and more at 15 °C than at 5 °C. The acceleration of ethanolic fermentation may allow production of some ATP, which may permit the carrot tissues to survive.

scholarly journals Looking beyond stratification: a model-based analysis of the biological drivers of oxygen deficiency in the North Sea

2016 ◽  
Vol 13 (8) ◽  
pp. 2511-2535 ◽  
Author(s):  
Fabian Große ◽  
Naomi Greenwood ◽  
Markus Kreus ◽  
Hermann-Josef Lenhart ◽  
Detlev Machoczek ◽  
...  
Keyword(s):  
North Sea ◽  
Oxygen Deficiency ◽  
Low Oxygen ◽  
The North ◽  
Oxygen Conditions ◽  
Southern Central ◽  
The North Sea ◽  
Central North Sea ◽  
The Impact ◽  
Oxygen Dynamics

Abstract. Low oxygen conditions, often referred to as oxygen deficiency, occur regularly in the North Sea, a temperate European shelf sea. Stratification represents a major process regulating the seasonal dynamics of bottom oxygen, yet, lowest oxygen conditions in the North Sea do not occur in the regions of strongest stratification. This suggests that stratification is an important prerequisite for oxygen deficiency, but that the complex interaction between hydrodynamics and the biological processes drives its evolution. In this study we use the ecosystem model HAMSOM-ECOHAM to provide a general characterisation of the different zones of the North Sea with respect to oxygen, and to quantify the impact of the different physical and biological factors driving the oxygen dynamics inside the entire sub-thermocline volume and directly above the bottom. With respect to oxygen dynamics, the North Sea can be subdivided into three different zones: (1) a highly productive, non-stratified coastal zone, (2) a productive, seasonally stratified zone with a small sub-thermocline volume, and (3) a productive, seasonally stratified zone with a large sub-thermocline volume. Type 2 reveals the highest susceptibility to oxygen deficiency due to sufficiently long stratification periods (>  60 days) accompanied by high surface productivity resulting in high biological consumption, and a small sub-thermocline volume implying both a small initial oxygen inventory and a strong influence of the biological consumption on the oxygen concentration. Year-to-year variations in the oxygen conditions are caused by variations in primary production, while spatial differences can be attributed to differences in stratification and water depth. The large sub-thermocline volume dominates the oxygen dynamics in the northern central and northern North Sea and makes this region insusceptible to oxygen deficiency. In the southern North Sea the strong tidal mixing inhibits the development of seasonal stratification which protects this area from the evolution of low oxygen conditions. In contrast, the southern central North Sea is highly susceptible to low oxygen conditions (type 2). We furthermore show that benthic diagenetic processes represent the main oxygen consumers in the bottom layer, consistently accounting for more than 50 % of the overall consumption. Thus, primary production followed by remineralisation of organic matter under stratified conditions constitutes the main driver for the evolution of oxygen deficiency in the southern central North Sea. By providing these valuable insights, we show that ecosystem models can be a useful tool for the interpretation of observations and the estimation of the impact of anthropogenic drivers on the North Sea oxygen conditions.

scholarly journals Nanostructured Equimolar Ceria-Praseodymia for Total Oxidations in Low-O2 Conditions

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 165 ◽  
Author(s):  
Enrico Sartoretti ◽  
Fabio Martini ◽  
Marco Piumetti ◽  
Samir Bensaid ◽  
Nunzio Russo ◽  
...  
Keyword(s):  
Active Oxygen Species ◽  
Oxygen Deficiency ◽  
Direct Injection ◽  
Particulate Filter ◽  
Low Oxygen ◽  
Total Oxidation ◽  
Gasoline Engines ◽  
Gasoline Particulate Filter ◽  
Complementary Techniques ◽  
Temperature Programmed

A Gasoline Particulate Filter (GPF) can be an effective solution to abate the particulate matter produced in modern direct injection gasoline engines. The regeneration of this system is critical, since it occurs in oxygen deficiency, but it can be promoted by placing an appropriate catalyst on the filter walls. In this paper, a nanostructured equimolar ceria-praseodymia catalyst, obtained via hydrothermal synthesis, was characterized with complementary techniques (XRD, N2-physisorption, FESEM, XPS, Temperature Programmed Reduction, etc.) and its catalytic performances were investigated in low oxygen availability. Pr-doping significantly affected ceria structure and morphology, and the weakening of the cerium–oxygen bond associated to Pr insertion resulted in a high reducibility. The catalytic activity was explored considering different reactions, namely CO oxidation, ethylene and propylene total oxidation, and soot combustion. Thanks to its capability of releasing active oxygen species, ceria-praseodymia exhibited a remarkable activity and CO2-selectivity at low oxygen concentrations, proving to be a promising catalyst for coated GPFs.

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