title: Glutamate kinase as a potential biomarker of heavy metal stress in plants.
abstract: Changes of glutamate kinase activity (GKA) in plants under cadmium and zinc chronic stress reported here reveal a regulatory role of this enzyme in plant heavy metal stress adaptation and indicate its potential use as a stress biomarker. Results of the first experimental series confirmed the toxic effects of cadmium and zinc at tested levels (30, 60, 90 mg Cd kg(-1) and 250, 500, 750 mg Zn kg(-1) soil) for spinach. A significant decrease of GKA in plants grown on contaminated treatments was found. Changes of GKA of plants grown on the highest contaminated treatments in the second series of experiments showed a similar course as a curve of plant stress response indicating the process of plant adaptation to chronic stresses--the decline of GKA in period of damage of cell activities, increase of its activity in period of maximum resistance and its following decrease in period of the plant metabolism depletion.
authors.affiliation: Department of Agrochemistry and Plant Nutrition, Czech University of Life Sciences, Kamycka 129, 16521 Prague, Czech Republic. pavlikova@af.czu.cz
authors.forename: Daniela
authors.initials: D
authors.lastname: Pavlíková
authors.forename: Milan
authors.initials: M
authors.lastname: Pavlík
authors.forename: Ludmila
authors.initials: L
authors.lastname: Staszková
authors.forename: Václav
authors.initials: V
authors.lastname: Motyka
authors.forename: Jirina
authors.initials: J
authors.lastname: Száková
authors.forename: Pavel
authors.initials: P
authors.lastname: Tlustos
authors.forename: Jirí
authors.initials: J
authors.lastname: Balík
mesh_terms: D000222:Adaptation, Physiological; D015415:Biomarkers / Q000378:metabolism; D002104:Cadmium / Q000378:metabolism / Q000633:toxicity*; D017851:Phosphotransferases (Carboxyl Group Acceptor) / Q000378:metabolism*; D035261:Plant Components, Aerial / Q000187:drug effects / Q000378:metabolism; D012989:Soil Pollutants / Q000378:metabolism / Q000633:toxicity*; D018724:Spinacia oleracea / Q000187:drug effects* / Q000378:metabolism; D015032:Zinc / Q000378:metabolism / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D012989:Soil Pollutants; D002104:Cadmium; D017851:Phosphotransferases (Carboxyl Group Acceptor); C020650:glutamate 5-kinase; D015032:Zinc