The long-term effect of zinc soil contamination on selected free amino acids playing an important role in plant adaptation to stress and senescence.
Increased endogenous plant cytokinin (CK) content through transformation with an isopentyl transferase (ipt) gene has been associated with improved plant stress tolerance. The objective of this study is to determine amino acid changes associated with elevated CK production in ipt transgenic tobacco (Nicotiana tabacum L., cv. Wisconsin 38). Nontransformed (WT) and transformed tobacco plants with ipt gene controlled by senescence-activated promoter (SAG) were exposed to zinc soil contamination (tested levels Zn1=250, Zn2=500, Zn3=750 mg kg(-1) soil). The Zn effect on plant stress metabolism resulted in changes in levels of selected free amino acids playing an important role in adaptation to stress and plant senescence (alanine, leucine, proline, methionine and γ-aminobutyrate) and differed for transformed and nontransformed tobacco plants. Analyses of amino acids confirmed that SAG tobacco plants had improved zinc tolerance compared with the WT plants. The enhanced Zn tolerance of SAG plants was associated with the maintenance of accumulation of proline, methionine and γ-aminobutyrate. The concentrations of leucine and alanine did not show significant differences between plant lines.
Department of Agro-Environmental Chemistry and Plant Nutrition, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, 16521 Prague, Czech Republic. Electronic address: pavlikova@af.czu.cz.
Daniela
D
Pavlíková
Department of Agro-Environmental Chemistry and Plant Nutrition, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, 16521 Prague, Czech Republic. Electronic address: zemanovav@af.czu.cz.
Veronika
V
Zemanová
Laboratory of Stress Physiology, Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, 16502 Prague, Czech Republic. Electronic address: prochazkovad@ueb.cas.cz.
Dagmar
D
Procházková
Isotope Laboratory, Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Vídeňská 1083, 14220 Prague, Czech Republic. Electronic address: pavlik@biomed.cas.cz.
Milan
M
Pavlík
Department of Agro-Environmental Chemistry and Plant Nutrition, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, 16521 Prague, Czech Republic. Electronic address: szakova@af.czu.cz.
Jiřina
J
Száková
Laboratory of Stress Physiology, Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, 16502 Prague, Czech Republic. Electronic address: wilhelmova@ueb.cas.cz.
Naďa
N
Wilhelmová
D000222:Adaptation, Physiological / Q000187:drug effects; D000596:Amino Acids / Q000032:analysis / Q000378:metabolism*; D003583:Cytokinins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012989:Soil Pollutants / Q000633:toxicity*; D013995:Time; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015032:Zinc / Q000633:toxicity*
D000596:Amino Acids; D003583:Cytokinins; D012989:Soil Pollutants; D015032:Zinc
Amino acid; Cytokinins; Plant; Senescence; Toxic element