title: Enhanced lipoxygenase activity is involved in the stress response but not in the harmful lipid peroxidation and cell death of short-term cadmium-treated barley root tip.
abstract: Root growth inhibition and radial root swelling were the characteristic symptoms of barley root tips after the short-term exposure of roots to 15 and 30μM Cd. Higher Cd concentrations caused extensive cell death and root growth arrest. Enhanced lipid peroxidation was observed as early as 1h after the short-term treatment in a Cd concentration-dependent manner. In contrast to lipid peroxidation, the induction of lipoxygenase activity was detected only 3h after the exposure of roots to 15 or 30μM Cd. In addition, it was not observed in 60μM Cd-treated root tips. The highest lipoxygenase activity was detected 6h after 15μM Cd treatment in the meristematic and elongation zone of root tip and was probably associated with the radial expansion of cells. Our results indicate that the upregulation of lipoxygenase is an important component of stress response in barley roots to toxic Cd. It is probably involved in the morphological stress response of root tips or/and in the alleviation of Cd-induced toxic alterations in plant cell membranes, but it is not responsible for the Cd-induced harmful lipid peroxidation and cell death.
authors: Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84523 Bratislava, Slovak Republic.
authors: Ľubica
authors: Ľ
authors: Liptáková
authors: Jana
authors: J
authors: Huttová
authors: Igor
authors: I
authors: Mistrík
authors: Ladislav
authors: L
authors: Tamás
mesh_terms: D002104:Cadmium / Q000633:toxicity*; D016923:Cell Death / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D001467:Hordeum / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development / Q000502:physiology; D007527:Isoenzymes; D015227:Lipid Peroxidation / Q000187:drug effects; D008084:Lipoxygenase / Q000187:drug effects / Q000378:metabolism*; D018519:Meristem / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development / Q000502:physiology; D010940:Plant Proteins / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development / Q000502:physiology; D013312:Stress, Physiological / Q000187:drug effects; D013997:Time Factors
chemical_list: D007527:Isoenzymes; D010940:Plant Proteins; D002104:Cadmium; D008084:Lipoxygenase