Polyamine metabolism in sunflower and wheat leaf discs under cadmium or copper stress

• Published in: Plant science (Limerick) Vol. 164; no. 2; pp. 293 - 299
• Main Authors: Groppa, Marı́a D, Benavides, Marı́a P, Tomaro, Marı́a L
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01.02.2003; Elsevier Science
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Cadmium; Copper; Economic plant physiology; Fundamental and applied biological sciences. Psychology; Heavy metal stress; Helianthus annuus; Metabolism; Metabolism. Physicochemical requirements; Mineral nutrition; Nutrition. Photosynthesis. Respiration. Metabolism; Plant physiology and development; Polyamines; Wheat; dSAM, decarboxylated S-adenosyl methionine; Cadmium; DAO, diamine oxidase; PAO, polyamine oxidase; Spd, spermidine; Pas, polyamines; Polyamines; ODC, ornithine decarboxylase; Put, putrescine; ADC, arginine decarboxylase; Helianthus annuus; Spm, spermine; SAM, S-adenosyl methionine; Copper; Wheat; Heavy metal stress; Monocotyledones; Arginine decarboxylase; Ethylene; Lyases; Biosynthesis; Compositae; Cereal crop; Enzymatic activity; Gramineae; Carboxy-lyases; Dicotyledones; Angiospermae; Plant tissue disc; Polyamine; Enzyme; Plant leaf; Ornithine decarboxylase; Metabolism; Amine oxidase (copper-containing); Heavy metal; Carbon-carbon lyases; Spermatophyta; Oxidoreductases; Oil plant (vegetal); Triticum aestivum
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/S0168-9452(02)00412-0

The influence of Cd 2+ or Cu 2+ on polyamine (Pa) metabolism and ethylene evolution was studied in sunflower and wheat leaf-discs. Both metals increased putrescine (Put) content in wheat leaves 280 and 90%, respectively, but reduced this Pa in sunflower leaves by about 50% of the control values. Spermidine content was diminished in cadmium and copper sunflower treated leaves (41 and 79%, respectively) while spermine was reduced by both metals in wheat (around 40%). In sunflower leaves, both metals greatly reduced arginine decarboxylase (ADC) activity, while ornithine decarboxylase (ODC) was only decreased by cadmium. However, in wheat leaves, cadmium increased ADC and ODC activities (210 and 2200% over the control, respectively), and Cu 2+ raised ODC activity fivefold respect to the control, with the resulting increase in Put concentration. Moreover, the decreased diamine oxidase activity observed with both metals in wheat leaves might contribute to the high Put level observed. Cadmium and copper increased ethylene production sixfold in wheat leaves, while in sunflower leaves, only copper produced a great increment in the hormone (300% over the control).