Phenolic compounds composition and physiological attributes of Matricaria chamomilla grown in copper excess

Four-week old plants of chamomile (Matricaria chamomilla) cultivated in nutrient solution were exposed to copper (3, 60 and 120 mu M) for 10 days. At 120 mu M, Cu decreased dry mass production, water, chlorophyll and nitrogen content in both the leaf rosettes and roots. Five phenolic acids were detected in methanol extracts of the leaf rosettes (protocatechuic, p-hydroxybenzoic, vanillic, chlorogenic and salicylic acid) and six additional compounds (gentisic, syringic, caffeic, sinapic and o-lp-coumaric acid) were released after acid hydrolysis. Most of the I I phenolic acids detected increased in 60 mu M Cu but in the 120 mu M treatment their contents were lower or not significantly different from the control. Among coumarin-related compounds, (Z)- and (E)-2-beta-D-glucopyranosyloxy-4-methoxycinnamic acids increased in 60 and 120 mu M Cu while herniarin rose in the 3 and 60 mu M Cu by the end of the experiment. The amounts of umbelliferone were not affected by any of the doses tested. These facts in relation to antioxidative properties of phenolic metabolites are also discussed. The malondialdehyde content of the leaf rosettes was not affected by exposure of plants to 120 mu M Cu in a time-course experiment but in the roots a sharp increase was observed after 24 and 48 h of treatment. At 120 mu M, Cu stimulated a 9-fold higher K+ loss than the 60 mu M treatment while at the lowest concentration it stimulated potassium uptake. Cu accumulation in the roots was 3-, 49- and 71-fold higher than that in the leaf rosettes in the 3, 60, and 120 mu M Cu treatments, respectively. Results suggest that 120 mu M Cu dose is limiting for chamomile growth under the conditions of present research. (c) 2007 Elsevier B.V. All rights reserved.