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Acute and chronic effect of copper on levels of reduced and oxidized glutathione and nutrient uptake of tomato plants
Author(s) -
Garrido Tatiana,
Mendoza Jorge,
Riveros Raúl,
Sáez Luis
Publication year - 2010
Publication title -
journal of plant nutrition and soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 1436-8730
DOI - 10.1002/jpln.200800306
Subject(s) - chlorosis , shoot , glutathione , phytotoxicity , chemistry , horticulture , toxicity , copper , nutrient , biomass (ecology) , acute toxicity , botany , agronomy , biology , biochemistry , organic chemistry , enzyme
Phytotoxicity due to copper (Cu) is generally associated with visible symptoms such as a decrease in plant shoot and root growth and chlorosis. The application of low levels of Cu or plant exposure to the metal for short periods can affect several cell processes, involving changes in the levels of metabolites related to the plant antioxidative response. The purpose of this study was to compare the response of the reduced and oxidized glutathione system and Cu uptake in tomato plants exposed to phytotoxic levels of Cu in hydroponic culture. Attention was centered on establishing whether determination of the levels of both peptides in plants exposed for a short period of time (acute treatment) compared with exposure for an extended period (chronic treatment) could be used as an early indicator of Cu stress in tomato plants. For the acute treatment, the plants were exposed to 0.4, 9, and 36 μM Cu for 48 h, and for the chronic treatment to 0.4, 3, and 12 μM Cu for 28 d. Results indicate that plants subjected to the chronic treatment showed toxicity symptoms, among them chlorosis and a drastic decrease of the aerial part and root biomass, an effect that was not observed in the plants subjected to the acute treatment. Moreover, Cu applied to the plant, either in the acute or in the chronic treatment, modified the levels of reduced and oxidized glutathione in shoots and roots. The most noticeable effect was observed on the concentration of reduced glutathione in roots, where the concentration of this peptide decreased as the Cu concentration increased, and this effect was independent of the morphological changes undergone by the root and of the time of Cu application. The similarity of the responses to the acute and the chronic treatments indicates that assessment of the redox state of glutathione in the roots of plants exposed to copper, especially the change in levels of reduced glutathione, may represent a good indicator of the early plant response to stress due to excessive Cu supply.