Phenolic metabolism of Matricaria chamomilla plants exposed to nickel.
We examined accumulation of phenolic acids, total soluble phenolics and flavonoids, and activities of phenolic metabolism-related enzymes (shikimate dehydrogenase (SKDH), phenylalanine ammonia-lyase (PAL), cinnamyl alcohol dehydrogenase (CAD), polyphenol oxidase (PPO)) in Matricaria chamomilla plants exposed to 3, 60 and 120 microM of nickel (Ni) for 10 days. Ni showed low toxicity as indicated by unaltered content of total soluble phenolics in the leaf rosettes. In the roots, the effects of Ni were more visible, including increased total phenolics and PAL activity, but a decrease in PPO activity was observed. CAD activity was not affected by any of the Ni concentrations. Cinnamic acid derivatives were affected more than benzoic acid derivatives. Accumulation of chlorogenic acid, an important antioxidant compound, was enhanced by Ni treatment (ca. 4-fold in 120 microM Ni). Accumulation of protocatechuic acid, a phenol with high chelating strength, even decreased in the leaf rosettes. These observations are discussed in connection to antioxidative properties of phenolic metabolites and previously tested metals (cadmium and copper).
Kovácik
Jozef
J
Department of Botany, Institute of Biology and Ecology, Faculty of Science, P.J. Safárik University, Mánesova 23, 041 67 Kosice, Slovak Republic. jozkovacik@yahoo.com
Klejdus
Borivoj
B
Backor
Martin
M
D005419:Flavonoids / Q000378:metabolism; D031168:Matricaria / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism*; D009532:Nickel / Q000494:pharmacology* / Q000633:toxicity; D010636:Phenols / Q000378:metabolism*; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D012995:Solubility / Q000187:drug effects
D005419:Flavonoids; D010636:Phenols; D009532:Nickel