Biochemical mechanisms and physiological consequences of the toxic effect of silver and mercury ions on higher plants

In general mechanics stress is clearly defined as the point or degree of bending of an elastic system at the very point of just symptomless reversibility and irreversible deformation or break. In medicine and botany, stress is supposed to indicate all situations beyond normal, defined by the observer. All organs of higher plants (with some exceptions) perform aerobic metabolism and are thus subject to activated oxygen species. Oxygen oversaturation and thus oxygen stress may occur under various different conditions. Since most abiotic and biotic stress situations in plants result in the accelerated production of ROS oxidative stress is a common signaling event in plant stress and redox regulation therefore plays a central role in the stress signaling network (PASTORI & FOYER 2002). In this review basic reactions operating during stress and defence will be discussed where certain prooxidative situations and antioxidative processes in plants will be dealt with.

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Assessment of the Environmental Hazard and Possibility of Processing of Refinement Tailings of Loparite Ores Concentration

Ecology and Industry of Russia ◽

10.18412/1816-0395-2020-12-46-51 ◽

2020 ◽

Vol 24 (12) ◽

pp. 46-51

Author(s):

A.A. Goryachev ◽

E.A. Krasavtseva ◽

V.V. Lashchuk ◽

P.V. Ikkonen ◽

A.A. Smirnov ◽

...

Keyword(s):

Toxic Effect ◽

Specific Activity ◽

Higher Plants ◽

Natural Radionuclides ◽

Water Extract ◽

Material Composition ◽

Distilled Water ◽

Average Content ◽

Waste Storage ◽

Ore Dressing

Geotechnical properties and material composition of loparite ore dressing tailings have been investigated. It was established that already at the stage of waste storage, heterogeneity of the material composition and contents of valuable components is formed. The average content of loparite and eudialyte in the refinement tailings is 1.1 and 0.5%, respectively. The effective specific activity of natural radionuclides 226Ra, 232Th and 40K and investigated samples is in range values 646±21 – 1300±24 Bk/kg. When leaching samples of tailings in distilled water, the concentration of fluorineions in the water extract significantly exceeds the MPC of water bodies for fishery and household purposes. By phytotesting it was found that water extracts of tailings and its dilution – enrichment do not have a significant toxic effect on the growths of higher plants.

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Alterations in Auxin and Cytokinin Metabolism of Higher Plants Due to Expression of Specific Genes From Pathogenic Bacteria: a Review

Functional Plant Biology ◽

10.1071/pp9930405 ◽

1993 ◽

Vol 20 (5) ◽

pp. 405 ◽

Cited By ~ 24

Author(s):

JD Hamill

Keyword(s):

Plant Physiology ◽

Transgenic Plants ◽

Pseudomonas Syringae ◽

Pathogenic Bacteria ◽

Higher Plants ◽

Plant Tissues ◽

Cytokinin Metabolism ◽

Ipt Gene ◽

New Approach ◽

Biochemical Mechanisms

This review deals with the physiological and morphological effects of altering the auxin/cytokinin balance in transgenic plants by expressing specific genes from pathogenic bacteria. Genes which have been used to alter auxin levels or sensitivity in transgenic plants include the iaaM/iaaH genes from Agrobacterium tumefaciens and A. rhizogenes; gene 5 and possibly gene 6b from A. tumefaciens; the rol B and possibly the rol A gene from A. rhizogenes and the iaaL gene from Pseudomonas syringae subsp. savastanoi (P. savastanoi). Genes which have been used to alter cytokinin levels in transgenic plants include the ipt gene from A. tumefaciens and the rol C gene from A. rhizogenes. A variety of biochemical mechanisms have been identified which result in alterations to phytohormone levels following expression of these genes in transgenic plants. Many of the effects on plant development are consistent with observations made following exogenous auxin and/or cytokinin application to plant tissues, and the availability of these genes offers a new approach to the study of plant physiology using transformation methodology.

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In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100083035 ◽

1978 ◽

Vol 36 (2) ◽

pp. 434-435

Author(s):

D. Reis ◽

B. Vian ◽

J. C. Roland

Keyword(s):

Cell Wall ◽

Self Assembly ◽

Plant Cell Wall ◽

Higher Plants ◽

Three Dimensional ◽

Cytochemical Study ◽

Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

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Localization of Adenosine Triphosphatase Activity in the Phleom of Nicotiana Tabacum

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100094401 ◽

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.

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A Scanning Electron Microscopic Study of Pro-Vascular Cellular Morphology in Chaetophora Incressata

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100119880 ◽

1985 ◽

Vol 43 ◽

pp. 638-639

Author(s):

A. E. Hotchkiss ◽

A. T. Hotchkiss ◽

R. P. Apkarian

Keyword(s):

Green Algae ◽

Vascular Plants ◽

Vascular System ◽

Higher Plants ◽

Wall Structure ◽

Electron Microscopic ◽

Physiological Processes ◽

Scanning Electron Microscopic Study ◽

Scanning Electron Microscopic ◽

Scanning Electron

Multicellular green algae may be an ancestral form of the vascular plants. These algae exhibit cell wall structure, chlorophyll pigmentation, and physiological processes similar to those of higher plants. The presence of a vascular system which provides water, minerals, and nutrients to remote tissues in higher plants was believed unnecessary for the algae. Among the green algae, the Chaetophorales are complex highly branched forms that might require some means of nutrient transport. The Chaetophorales do possess apical meristematic groups of cells that have growth orientations suggestive of stem and root positions. Branches of Chaetophora incressata were examined by the scanning electron microscope (SEM) for ultrastructural evidence of pro-vascular transport.

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