scholarly journals Isoprene: An Antioxidant Itself or a Molecule with Multiple Regulatory Functions in Plants?

Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 684
Author(s):  
Susanna Pollastri ◽  
Ivan Baccelli ◽  
Francesco Loreto
Keyword(s):  
Metabolic Flux ◽  
Mep Pathway ◽  
Protective Mechanism ◽  
Oxygen Species ◽  
Terrestrial Plants ◽  
Oxidative Stresses ◽  
Low Concentrations ◽  
Volatile Organic ◽  
Regulatory Functions ◽  
Reduced State

Isoprene (C5H8) is a small lipophilic, volatile organic compound (VOC), synthesized in chloroplasts of plants through the photosynthesis-dependent 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway. Isoprene-emitting plants are better protected against thermal and oxidative stresses but only about 20% of the terrestrial plants are able to synthesize isoprene. Many studies have been performed to understand the still elusive isoprene protective mechanism. Isoprene reacts with, and quenches, many harmful reactive oxygen species (ROS) like singlet oxygen (1O2). A role for isoprene as antioxidant, made possible by its reduced state and conjugated double bonds, has been often suggested, and sometimes demonstrated. However, as isoprene is present at very low concentrations compared to other molecules, its antioxidant role is still controversial. Here we review updated evidences on the function(s) of isoprene, and outline contrasting indications on whether isoprene is an antioxidant directly scavenging ROS, or a membrane strengthener, or a modulator of genomic, proteomic and metabolomic profiles (perhaps as a secondary effect of ROS removal) eventually leading to priming of antioxidant plant defenses, or a signal of stress for neighbor plants alike other VOCs, or a hormone-like molecule, controlling the metabolic flux of other hormones made by the MEP pathway, or acting itself as a growth and development hormone.

ABOUT SOME PECULIARITIES OF THE PHYSIOLOGICAL HETEROGENEITY OF THE POPULATION OF SCENEDESMUS QUADRICAUDA (TURP.) BREB. IN THE PRESENCE OF LOW CONCENTRATIONS OF METALS

2018 ◽  
pp. 34-43
Author(s):  
V. I. Ipatova ◽  
A. G. Dmitrieva ◽  
О. F. Filenko ◽  
T. V. Drozdenko
Keyword(s):  
Cell Division ◽  
Toxic Effect ◽  
Copper Chloride ◽  
Single Cells ◽  
Physiological State ◽  
Scenedesmus Quadricauda ◽  
Physiological Status ◽  
Lag Phase ◽  
Protective Mechanism ◽  
Low Concentrations

The structure of the laboratory population of green microalgae Scenedesmus quadricauda (Turp.) Breb (=Desmodesmus communis E. Hegew.) was studied at different stages of its growth (lag-phase, log-phase and stationary phase) at low concentrations of copper chloride and silver nitrate by the method microculture, allowing to monitor the state and development of single cells having different physiological status. The response of the culture of S. quadricauda - the change in the number of cells and the fractional composition (the fraction of dividing, «dormant» and dying cells) depended not only on the concentration of the toxicant in the medium, but also on the physiological state of the culture: the level of synchronization and the growth phase. Silver ions at low concentrations had a more pronounced toxic effect on the culture than copper ions at different phases of its development, especially at a concentration of 0.001 mg/l (10-9 M). The main mechanism of the toxic effect of metals is to inhibit the process of cell division. At low concentrations of toxicants, especially at a concentration of 0.001 mg/l, a «paradoxical» effect expressed in the predominance of the fraction of «dormant» cells was revealed. The temporary inhibition of the process of cell division can be regarded as a protective mechanism that allows preserving the integrity of the population and its ability to survive in a changing environment. The obtained data explain the effect of action of low concentrations of substances due to their inclusion in the cell, the subsequent accumulation in the cell and their low excretion.

scholarly journals Application of non-equilibrium plasmas in medicine

2012 ◽  
Vol 77 (12) ◽  
pp. 1689-1699 ◽  
Author(s):  
Zoran Petrovic ◽  
N. Puac ◽  
G. Malovic ◽  
S. Lazovic ◽  
D. Maletic ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Medical Applications ◽  
Gas Mixture ◽  
Oxygen Species ◽  
Special Issue ◽  
Plasma Sources ◽  
Volatile Organic ◽  
Plasma Needle ◽  
Group A ◽  
Non Equilibrium

We review the potential of plasma medical applications, the connections to nanotechnologies and the results obtained by our group. A special issue in plasma medicine is the development of the plasma sources that would achieve non-equilibrium at atmospheric pressure in atmospheric gas mixture with no or only marginal heating of the gas, and with desired properties and mechanisms that may be controlled. Our studies have shown that control of radicals or chemically active products of the discharge such as ROS (reactive oxygen species) and/or NO may be used to control the growth of the seeds. At the same time specially designed plasma needle and other sources were shown to be efficient to sterilize not only colonies of bacteria but also planctonic samples (microorganisms protected by water) or bio films. Finally we have shown that plasma may induce differentiation of stem cells. Non-equilibrium plasmas may be used in detection of different specific markers in medicine. For example proton transfer mass spectroscopy may be employed in detection of volatile organic compounds without their dissociation and thus as a technique for instantaneous measurement of the presence of markers for numerous diseases.

scholarly journals Molecular Characterization of Reactive Oxygen Species in Myocardial Ischemia-Reperfusion Injury

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Tingyang Zhou ◽  
Chia-Chen Chuang ◽  
Li Zuo
Keyword(s):  
Reactive Oxygen Species ◽  
Myocardial Ischemia ◽  
Energy Demand ◽  
Heart Diseases ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
High Energy ◽  
Protective Mechanism ◽  
Oxygen Species ◽  
Myocardial Ischemia Reperfusion

Myocardial ischemia-reperfusion (I/R) injury is experienced by individuals suffering from cardiovascular diseases such as coronary heart diseases and subsequently undergoing reperfusion treatments in order to manage the conditions. The occlusion of blood flow to the tissue, termed ischemia, can be especially detrimental to the heart due to its high energy demand. Several cellular alterations have been observed upon the onset of ischemia. The danger created by cardiac ischemia is somewhat paradoxical in that a return of blood to the tissue can result in further damage. Reactive oxygen species (ROS) have been studied intensively to reveal their role in myocardial I/R injury. Under normal conditions, ROS function as a mediator in many cell signaling pathways. However, stressful environments significantly induce the generation of ROS which causes the level to exceed body’s antioxidant defense system. Such altered redox homeostasis is implicated in myocardial I/R injury. Despite the detrimental effects from ROS, low levels of ROS have been shown to exert a protective effect in the ischemic preconditioning. In this review, we will summarize the detrimental role of ROS in myocardial I/R injury, the protective mechanism induced by ROS, and potential treatments for ROS-related myocardial injury.

scholarly journals Oxidative Stress of Plants: Chemistry, Physiology, Methods of Protection

2021 ◽  
pp. 30-43
Author(s):  
Ekaterina Khozeeva ◽  
◽  
Yuliya Zimina ◽  
Galina Sroslova ◽  
◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Protective Mechanism ◽  
Oxygen Species ◽  
Biotic And Abiotic Stress ◽  
Stress Effects ◽  
Agricultural Plants ◽  
A Chain ◽  
Main Components

Under conditions of biotic and abiotic stress, reactive oxygen species (ROS) are formed in plants, which causes oxidative stress. At the same time, ROS play additional signaling roles in plant adaptation to stress. The study of the mechanisms of this process makes it possible to develop new ways of protecting organisms, in particular, agricultural plants, from negative stress effects. This review describes the current understanding of oxidative stress – the process of inhibition of the vital activity of cells under the action of reactive oxygen species. The distinctive features of plant oxidative stress and two main pathways of metabolic protection – the jasmonate and salicylate pathways – are separately identified. Various ways of identifying oxidative stress are also given. Innovative methods of protecting agricultural plants from oxidative stress are considered: the use of biopesticides – rhizobacteria and microscopic fungi, elicitors – the youngest direction in creating effective methods of protection. It also describes a relatively outdated method of protection – the use of fungicides. These substances were included in the review due to the recent appearance of biodegradable preparations of this type. Special attention is paid to elicitors – substances that are not typical for plants, the appearance of which in the cell causes a chain of biochemical processes similar to the metabolism of plants under oxidative stress. The most studied substances with the properties of elicitors are described: salicylic acid, jasmonates, hytosan and hydrogen peroxide; their role in the chain of response reactions. As an alternative, isothiocyanates – the main components of the “mustard bomb” – the protective mechanism of plants of the cruciferous family are considered. Also, the latest studies of isothiocyanates in the metabolic processes of plants are described.

Blood concentrations of volatile organic compounds in a nonoccupationally exposed US population and in groups with suspected exposure

1994 ◽  
Vol 40 (7) ◽  
pp. 1401-1404 ◽  
Author(s):  
D L Ashley ◽  
M A Bonin ◽  
F L Cardinali ◽  
J M McCraw ◽  
J V Wooten
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Reference Range ◽  
Industrialized Countries ◽  
Blood Concentrations ◽  
Health And Nutrition ◽  
Low Concentrations ◽  
Study Results ◽  
The Us ◽  
Volatile Organic

Abstract Exposure to certain volatile organic compounds (VOCs) commonly occurs in industrialized countries. We developed a method for measuring 32 VOCs in 10 mL of whole blood at low concentration. We used this method to determine the internal dose of these compounds in 600 or more people in the US who participated in the Third National Health and Nutrition Examination Survey. From our study results, we established a reference range for these VOCs in the general population of the US. We found detectable concentrations of 1,1,1-trichloroethane, 1,4-dichlorobenzene, 2-butanone, acetone, benzene, chloroform, ethylbenzene, m,p-xylene, styrene, tetrachloroethane, and toluene in most of the blood samples of nonoccupationally exposed persons. The accuracy of VOC evaluations depends on the ability of investigators to make sensitive and reproducible measurements of low concentrations of VOCs and to eliminate all sources of interference and contamination.

Ammonium utilization in Bacillus subtilis: transport and regulatory functions of NrgA and NrgB

Microbiology ◽  
2003 ◽  
Vol 149 (11) ◽  
pp. 3289-3297 ◽  
Author(s):  
Christian Detsch ◽  
Jörg Stülke
Keyword(s):  
Bacillus Subtilis ◽  
Large Fraction ◽  
Glutamate Synthase ◽  
Nitrogen Sources ◽  
Covalent Modification ◽  
Ammonium Transporter ◽  
Ammonium Ion ◽  
Ammonium Transport ◽  
Low Concentrations ◽  
Regulatory Functions

Bacillus subtilis uses glutamine as the best source of nitrogen. In the absence of glutamine, alternative nitrogen sources such as ammonium can be used. Ammonium utilization involves the uptake of the gas or the ammonium ion, the synthesis of glutamine by the glutamine synthetase and the recycling of the glutamate by the glutamate synthase. In this work, ammonium transport in B. subtilis was studied. At high ammonium concentrations, a large fraction of the ammonium is present as ammonia, which may enter the cell via diffusion. In contrast, the ammonium transporter NrgA is required for ammonium utilization at low concentrations or at low pH values when the equilibrium between uncharged ammonia and the ammonium ion is shifted towards ammonium. Moreover, a functional NrgA is essential for the transport of the ammonium analogue methylammonium. NrgA is encoded in the nrgAB operon. The product of the second gene, NrgB, is a member of the PII family of regulatory proteins. In contrast to PII proteins from other organisms, there is no indication for a covalent modification of NrgB in response to the nitrogen supply of the cell. It is demonstrated here that NrgB is localized at the membrane, most likely in association with the ammonium transporter NrgA. The presence of a functional NrgB is required for full-level expression of the nrgAB operon in response to nitrogen limitation, suggesting that NrgB might relay the information on ammonium availability to downstream regulatory factors and thus fine-tune their activity.

Detection and discrimination of volatile organic compounds by noble metal nanoparticle functionalized MoS2 coated biodegradable paper sensors

2020 ◽  
Vol 44 (38) ◽  
pp. 16613-16625
Author(s):  
Radha Bhardwaj ◽  
Venkatarao Selamneni ◽  
Uttam Narendra Thakur ◽  
Parikshit Sahatiya ◽  
Arnab Hazra
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Noble Metal ◽  
Low Cost ◽  
Metal Nanoparticle ◽  
Selective Detection ◽  
Low Concentrations ◽  
Volatile Organic

In the current study, noble metal nanoparticle functionalized MoS2 coated biodegradable low-cost paper sensors were fabricated for the selective detection of low concentrations of volatile organic compounds (VOCs).

Further experiments on the value of dissolved organic matter as food for Siboglinum fiordicum (Pogonophora)

1979 ◽  
Vol 59 (1) ◽  
pp. 133-148 ◽  
Author(s):  
A. J. Southward ◽  
Eve C. Southward ◽  
T. Brattegard ◽  
T. Bakke
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Organic Matter ◽  
Organic Acids ◽  
Experimental Conditions ◽  
Larval Stages ◽  
Low Concentrations ◽  
Volatile Organic ◽  
Volatile Organic Acids ◽  
Almost All

Adult and larval stages of Siboglinum fiordicum, collected from 32 to 35 m depth, accumulate measurable quantities of amino acids and glucose from low concentrations. The amino acids are absorbed against a considerable gradient. The glucose and the amino acids are metabolized in the tissues and substantial amounts are respired to give carbon dioxide or volatile organic acids. Under the experimental conditions almost all the metabolism follows aerobic pathways.

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