scholarly journals Association of antioxidative enzymes with the synergistic effect of selenium and UV irradiation in enhancing plant growth

2000 ◽  
Vol 9 (2) ◽  
pp. 177-186 ◽  
Author(s):  
T. XUE ◽  
H. HARTIKAINEN
Keyword(s):  
Synergistic Effect ◽  
Uv Irradiation ◽  
Antioxidative Enzymes ◽  
Higher Plants ◽  
High Energy ◽  
Glutathione S Transferase ◽  
Animal Cells ◽  
Normal Light ◽  
Addition Level

Selenium (Se) is able to defend human and animal cells against UV(B) stress. Higher plants are generally considered not to require Se but to have a low tolerance to it. However, recently it has been demonstrated that Se is able to protect also plants against UV-induced oxidative stress and even to promote the growth of plants subjected to high-energy light. In the present study the effects of Se on antioxidative enzymes possibly associated with this synergistic effect were investigated. Ryegrass and lettuce were grown in soil supplemented with Se at 0, 0.1 or 1.0 mg kg-1 under normal light or subjected to UV episodes. Lipid peroxidation and the changes of antioxidative enzymes were measured at two growing stages. The positive synergistic effect of the lower Se dosage and UV was found to be at least partly associated with the antioxidative role of Se through increased glutathione peroxidase (GSH-Px) and catalase (CAT) activity, whereas ascorbate peroxidase (APX) responded negatively to both factors. The contribution of the other enzymes studied seemed to be plant-specific: glutathione S-transferase (GST) increased in both ryegrass assays and superoxide dismutase (SOD) in the first lettuce assay. At the higher addition level Se acted as a pro-oxidant and diminished fresh weight yields. UV irradiation alleviated the toxicity coincidently with increase of CAT in ryegrass and SOD in lettuce.;

scholarly journals Comparative proteomic analysis provides new insights into regulation of microspore embryogenesis induction in winter triticale (× Triticosecale Wittm.) after 5-azacytidine treatment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Monika Krzewska ◽  
Ewa Dubas ◽  
Gabriela Gołębiowska ◽  
Anna Nowicka ◽  
Agnieszka Janas ◽  
...  
Keyword(s):  
Energy Demand ◽  
Protein Biosynthesis ◽  
Gene Expression Pattern ◽  
Microspore Embryogenesis ◽  
High Energy ◽  
Glutathione S Transferase ◽  
Winter Triticale ◽  
Dh Lines ◽  
Cell Proteome

AbstractEffective microspore embryogenesis (ME) requires substantial modifications in gene expression pattern, followed by changes in the cell proteome and its metabolism. Recent studies have awakened also interest in the role of epigenetic factors in microspore de-differentiation and reprogramming. Therefore, demethylating agent (2.5–10 μM 5-azacytidine, AC) together with low temperature (3 weeks at 4 °C) were used as ME-inducing tiller treatment in two doubled haploid (DH) lines of triticale and its effect was analyzed in respect of anther protein profiles, expression of selected genes (TAPETUM DETERMINANT1 (TaTPD1-like), SOMATIC EMBRYOGENESIS RECEPTOR KINASE 2 (SERK2) and GLUTATHIONE S-TRANSFERASE (GSTF2)) and ME efficiency. Tiller treatment with 5.0 µM AC was the most effective in ME induction; it was associated with (1) suppression of intensive anabolic processes-mainly photosynthesis and light-dependent reactions, (2) transition to effective catabolism and mobilization of carbohydrate reserve to meet the high energy demand of cells during microspore reprograming and (3) effective defense against stress-inducing treatment, i.e. protection of proper folding during protein biosynthesis and effective degradation of dysfunctional or damaged proteins. Additionally, 5.0 µM AC enhanced the expression of all genes previously identified as being associated with embryogenic potential of microspores (TaTPD1-like, SERK and GSTF2).

scholarly journals Human GSTA1-1 reduces c-Jun N-terminal kinase signalling and apoptosis in Caco-2 cells

2006 ◽  
Vol 400 (1) ◽  
pp. 135-141 ◽  
Author(s):  
Laura Romero ◽  
Kimberly Andrews ◽  
Lorraine Ng ◽  
Kelly O'Rourke ◽  
Ann Maslen ◽  
...  
Keyword(s):  
Uv Irradiation ◽  
Protective Role ◽  
Stress Conditions ◽  
Glutathione S Transferase ◽  
Kinase Activation ◽  
Protein Levels ◽  
Induced Apoptosis ◽  
Factor Α ◽  
Jnk Activation

The effect of GSTA1-1 (glutathione S-transferase Alpha 1-1) on JNK (c-Jun N-terminal kinase) activation was investigated in Caco-2 cells in which GSTA1 expression increases with degree of confluency, and in MEF3T3 cells with Tet-Off-inducible GSTA1 expression. Comparison of GSTA1 expression in pre-confluent, confluent and 8-day post-confluent Caco-2 cells revealed progressively increasing mRNA and protein levels at later stages of confluency. Exposure of pre-confluent cells to stress conditions including IL-1β (interleukin-1β), H2O2 or UV irradiation resulted in marked increases in JNK activity as indicated by c-Jun phosphorylation. However, JNK activation was significantly reduced in post-confluent cells exposed to the same stresses. Western-blot analysis of GSTA1-1 protein bound to JNK protein pulled down from cellular extracts showed approx. 4-fold higher GSTA1-1–JNK complex formation in post-confluent cells compared with pre-confluent cells. However, stress conditions did not alter the amount of GSTA1-1 bound to JNK. The role of GSTA1-1 in JNK suppression was more specifically revealed in Tet-Off-inducible MEF3T3-GSTA1-1 cells in which GSTA1 overexpression significantly reduced phosphorylation of c-Jun following exposure to IL-1β, H2O2 and UV irradiation. Finally, the incidence of tumour necrosis factor α/butyrate-induced apoptosis was significantly higher in pre-confluent Caco-2 cells expressing low levels of GSTA1 compared with post-confluent cells. These results indicate that GSTA1 suppresses activation of JNK signalling by a pro-inflammatory cytokine and oxidative stress and suggests a protective role for GSTA1-1 in JNK-associated apoptosis.

The Organization of the Cytoskeleton During Meiosis in Eggplant (Solanum Melongena (L.)): Microtubules and F-Actin are Both Necessary for Coordinated Meiotic Division

1989 ◽  
Vol 92 (4) ◽  
pp. 541-550 ◽  
Author(s):  
J. A. TRAAS ◽  
S. BURGAIN ◽  
R. DUMAS DE VAULX
Keyword(s):  
Higher Plants ◽  
Solanum Melongena ◽  
Preprophase Band ◽  
Male Meiosis ◽  
Animal Cells ◽  
Division Plane ◽  
Nucleation Sites ◽  
Division Process ◽  
Spatial Programming

Address for reprints Because two division planes form at right angles, male meiosis in higher plants provides striking examples of both division control and spatial programming. To investigate these processes we have stained microtubules and actin filaments during male meiosis in the eggplant. Our results indicate the following. (1) That microtubules and their nucleation sites are involved in the establishment of polarity; this is supported by our observation that the drug CIPC affects spindle polarity.(2) That actin microfilaments are involved in spindle formation and integrity, but not in the establishment of polarity: cytochalasin B and D affect the organization of the spindle microtubules, but not their polarized distribution.(3) That microtubules radiating from the daughter nuclei at the cell poles during interkinesis probably establish the future division plane by concentrating actin in that plane (cf. the proposed role of asters in positioning the contractile ring in animal cells).(4) That this concentration of F-actin in the division plane may be involved in preparing the cytoplasm for cytokinesis and in memorizing the division plane (much as the preprophase band observed in polarized tissues does).(5) That phragmoplast formation is a two-step process. No phragmoplast forms after metaphase I, but a four-way phragmoplast forms after metaphase II, indicating that mitosis and cytokinesis are not obligatorily coupled. These studies demonstrate that actin and microtubules are jointly involved in the spatial coordination of the division process.

Carbon-Induced UV Sensitivity in Aluminum Nitride

1998 ◽  
Vol 4 (S2) ◽  
pp. 570-571
Author(s):  
Y. Berta ◽  
R. A. Gerhardt
Keyword(s):  
Dielectric Loss ◽  
Aluminum Nitride ◽  
Uv Irradiation ◽  
High Performance ◽  
High Energy ◽  
Multichip Modules ◽  
Low Oxygen ◽  
Carbon Impurities ◽  
Ultimate Purpose

Aluminum nitride, translucent, calcia-sintered and hot pressed, with its superior thermal properties has applications in high performance electronic devices such as multichip modules. In these applications, A1N is exposed to high energy electromagnetic sources which could alter its properties; for example, upon UV irradiation, thermal conductivity drops and dielectric loss increases. These observations indicate that the UV altered properties are due to the presence of impurities. The early studies concentrated primarily on oxygen doped samples, which photodarken upon UV exposure; the role of other impurities was not considered.In the current work, we consider the role of carbon in the microstructure of two very low oxygen content (< 0.3 wt %), carbon-containing samples, labeled B and E, for the ultimate purpose of 3 determining the mechanism by which carbon impurities affect the properties of A1N. Previous work on these samples correlated higher carbon content with a lower increase in the dielectric loss factor, after UV irradiation,

Localization of Adenosine Triphosphatase Activity in the Phleom of Nicotiana Tabacum

1972 ◽  
Vol 30 ◽  
pp. 230-231
Author(s):  
James Cronshaw ◽  
Jamison E. Gilder
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Higher Plants ◽  
High Surface ◽  
Root Tip ◽  
Animal Cells ◽  
Physiological Processes ◽  
Tip Cells ◽  
Atpase Localization

Adenosine triphosphatase (ATPase) activity has been shown to be associated with numerous physiological processes in both plants and animal cells. Biochemical studies have shown that in higher plants ATPase activity is high in cell wall preparations and is associated with the plasma membrane, nuclei, mitochondria, chloroplasts and lysosomes. However, there have been only a few ATPase localization studies of higher plants at the electron microscope level. Poux (1967) demonstrated ATPase activity associated with most cellular organelles in the protoderm cells of Cucumis roots. Hall (1971) has demonstrated ATPase activity in root tip cells of Zea mays. There was high surface activity largely associated with the plasma membrane and plasmodesmata. ATPase activity was also demonstrated in mitochondria, dictyosomes, endoplasmic reticulum and plastids.

Characteristics Of The Structure Formation Of Gypsum Binder Modified With Zinc Hydrosilicates

2020 ◽  
pp. 40-46
Keyword(s):  
Synergistic Effect ◽  
Physicochemical Properties ◽  
Structure Formation ◽  
Silicic Acid ◽  
Chemical Properties ◽  
Crystal Formation ◽  
Ability To Act ◽  
Chemical Factors ◽  
Sorption Characteristics

The authors' methodic for assessing the role of chemical and physic-chemical factors during the structure formation of gypsum stone is presented in the article. The methodic is also makes it possible to reveal the synergistic effect and to determine the ranges of variation of controls factors that ensure maximum values of such effect. The effect of a micro-sized modifier based on zinc hydro-silicates on the structure formation of building gypsum is analyzed and corresponding dependencies are found. It is shown that effects of influence of modifier on the properties of gypsum compositions are determined by chemical properties of modifier. Among the mentioned properties are sorption characteristics (which depend on the amount of silicic acid and its state) and physicochemical properties - the ability to act as a substrate during crystal formation. The proposed method can also be extended to other binding substances and materials. This article contributes to the understanding of the processes that occur during the structure formation of composites, which will make it possible to control the structure formation in the future, obtaining materials with a given set of properties.

Physiological Role of Cyclic Electron Flow in Higher Plants

2012 ◽  
Vol 30 (1) ◽  
pp. 100
Author(s):  
Wei HUANG ◽  
Shi-Bao ZHANG ◽  
Kun-Fang CAO
Keyword(s):  
Higher Plants ◽  
Electron Flow ◽  
Physiological Role ◽  
Cyclic Electron Flow

Fundamentality

2017 ◽  
Author(s):  
Richard Healey
Keyword(s):  
Quantum Theory ◽  
High Energy Physics ◽  
Physical Property ◽  
Natural World ◽  
High Energy ◽  
Quantum Field Theories ◽  
Fundamental Physics ◽  
The World ◽  
Energy Physics

The metaphor that fundamental physics is concerned to say what the natural world is like at the deepest level may be cashed out in terms of entities, properties, or laws. The role of quantum field theories in the Standard Model of high-energy physics suggests that fundamental entities, properties, and laws are to be sought in these theories. But the contextual ontology proposed in Chapter 12 would support no unified compositional structure for the world; a quantum state assignment specifies no physical property distribution sufficient even to determine all physical facts; and quantum theory posits no fundamental laws of time evolution, whether deterministic or stochastic. Quantum theory has made a revolutionary contribution to fundamental physics because its principles have permitted tremendous unification of science through the successful application of models constructed in conformity to them: but these models do not say what the world is like at the deepest level.

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