Biochemical mechanisms of detoxification in higher plants

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Biochemical mechanisms of detoxification in higher plants

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[...]... leading to the formation of polychlorinated contaminants Dioxins are also formed in high-temperature chemical processes (including garbage incineration) in which organic and inorganic compounds with one or more atoms of chlorine (including molecular chlorine) participate Automobiles are another source of dioxins These compounds end up in the exhausts along with the combustion gases from the engines of. .. cadmium inhibits the action of zinc-containing enzymes and damages the normal functioning of the kidneys, resulting in proteinuria In the liver, cadmium blocks the activities of enzymes containing SH-groups [315] Earthworms are capable to rapidly accumulate cadmium from soil; consequently they are often used as bioindicators of cadmium [277] 1.1.11 Gaseous contaminants Many gases contained in air are... microbiological transformations of sulfur-containing compounds Once in the atmosphere, SO2 can bind with water, thereby maintaining its stable concentration in the air The burning of coal and oil, metallurgical processes and the processing of sulfur-containing ore form anthropogenic SO2 Most of the anthropogenic sources of SO2 (about 87%) are connected with power engineering and industry The total anthropogenic... and the digestive tract Depending on dose, arsenic and its compounds are carcinogenic (International Agency for Research on Cancer) [246], causing cancer of the skin, liver, intestines, bladder and lungs The long-term use of arsenic-containing insecticides against phylloxera induced the so-called “cancer of the viticulturist”, a cancer disease typical for people working in vineyards [145] Some tropical... the chemical industry For the production of paper from woody raw material, lignin must be 1.1 Environmental contaminants 9 eliminated to leave just the cellulose This delignification process implies the interaction of phenolic lignin fragments with chlorine reagents resulting in the formation of dioxins or their precursors During the standard bleaching process of woody polysaccharides, chlorine or its... anthropogenic sources of lead are waste extracted during high temperature processes in metallurgy, metal working, engineering, chemical, chemico-pharmaceutical, petrochemical and other industries; and the exhaust gases of internal combustion engines using lead-containing petrol High levels of lead contamination are typically found in the soils of military proving grounds [1] Lead compounds (oxides, chlorides,... metabolites, other ingredients) might be considered as compounds having a (very low) toxicity, although their consumption in small amounts is harmless The United States Food and Drug Administration (FDA) has created and maintains a list of common plant toxins, and guidelines defining acceptable toxin levels A number of medical supplies, including antibiotics, also belong to the category of substances of low toxicity... substance of group C In animals TNT is slowly metabolized via the reduction of nitro groups leading to the formation of nitroso derivatives, hydroxylaminodinitrotoluenes, aminodinitrotoluenes (ADNTs) and diaminonitrotoluenes Besides, oxidation of the methyl group and formation of nitro- and amino-derivatives of benzyl alcohol and benzoic acid may take place Some of these metabolites (mainly amino-derivatives)... found in the gas used in the chlorination of water supplies Polychlorinated contaminants are formed as admixtures during the interaction of chlorine with carbon (e.g., of electrodes and aerial oxygen) It should be stressed that dioxins constitute a serious hazard to the environment and human health [90] According to the rate of environmental contamination by dioxins the pulp and paper industry is the second... described in the following section Arsenic This element occurs in the ores of copper, lead, iron, nickel, cobalt and other metals All compounds of arsenic are highly toxic Upon heating they are decomposed, releasing poisonous arsenical vapors The main sources of environmental contamination by arsenic are emissions from the mining industry, the production of arsenic and its compounds, the smelting of copper, . parameters determining the continuing existence of mankind. The inexorable and seemingly permanent increase of technogenic contaminants in all ecological. understanding of the mechanisms of detoxification of environmental contaminants in plants; to describe the principles of the practical realization of these

Ngày đăng: 16/03/2014, 18:07

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