Journal
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
Volume 75, Issue -, Pages 8-15Publisher
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.ecoenv.2011.08.029
Keywords
Copper toxicity; Metallophytes; Organic acids; Phenolic compounds; Root exudates
Categories
Funding
- National Commission for Scientific and Technological Research (CONICYT), through FONDECYT [11080131]
- Scientific and Technological National Commission Research (CONICYT) [24091053]
Ask authors/readers for more resources
A hydroponic experiment was carried out to determine the root exudation patterns in two Cu-metallophytes (Oenothera picensis and Imperata condensata) and two agricultural plants (Lupinus albus and Helianthus annuus). Plants were grown in nutrient solution at increasing Cu doses (0, 0.125, 0.25, 0.5, 1 and 2 mg Cu L-1), and plant growth, root elongation, Cu accumulation and root exudates were measured. All plants showed a decrease of over 60% in root elongation at the highest Cu supply level, being O. picensis the most sensitive specie and showing the highest shoot and root Cu concentrations (116 and 2657 mu g Cu g(-1), respectively), which were six fold higher than the other species. Differences in root exudation patterns of low molecular weight organic acids were found, with extremely high amounts of succinic acid exuded by O. picensis (1049 mu mol g(-1) h(-1)), and citric acid by I. condensata (164 mu mol g(-1) h(-1)). In metallophytes, the organic acid exudation was increased even with no root elongation, meanwhile agricultural plants exuded citric acid at constant levels. Exudation of phenolic compounds was highly species-dependent, with catechin mainly exuded by I. condensata, (2.62 mu mol g(-1) h(-1)) cinnamic acid by O. picensis (5.08 mu mol g(-1) h(-1)) and coumaric acid exclusively exuded by H. annuus (13.6 mu mol g(-1) h(-1)) at high Cu levels. These results indicated that differences in root exudation patterns among metallophytes and agricultural plants could affect their Cu tolerance. Particularly, the higher exudation rate showed by I. condensata can be an effective exclusion mechanism to tolerate high Cu concentrations, supporting its use in Cu phytostabilization programs. (C) 2011 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available