Impact of copper toxicity on stone-head cabbage (Brassica oleracea var. capitata) in hydroponics.
Arable soils are frequently subjected to contamination with copper as the consequence of imbalanced fertilization with manure and organic fertilizers and/or extensive use of copper-containing fungicides. In the present study, the exposure of stone-head cabbage (Brassica oleracea var. capitata) to elevated Cu(2+) levels resulted in leaf chlorosis and lesser biomass yield at ≥2 µ M. Root nitrate content was not statistically affected by Cu(2+) levels, although it was substantially decreased at ≥5 µ M Cu(2+) in the shoot. The decrease in nitrate contents can be related to lower nitrate uptake rates because of growth inhibition by Cu-toxicity. Shoot sulfate content increased strongly at ≥2 µ M Cu(2+) indicating an increase in demand for sulfur under Cu stress. Furthermore, at ≥2 µM concentration, concentration of water-soluble non-protein thiol increased markedly in the roots and to a smaller level in the shoot. When exposed to elevated concentrations of Cu(2+) the improved sulfate and water-soluble non-protein thiols need further studies for the evaluation of their direct relation with the synthesis of metal-chelating compounds (i.e., phytochelatins).
Institute of Agricultural Sciences, University of the Punjab , Lahore , Pakistan.
Sajid
S
Ali
Institute of Agricultural Sciences, University of the Punjab , Lahore , Pakistan ; Department of Biology, Colorado State University , Fort Collins, Colorado , USA.
Muhammad
M
Shahbaz
Department of Agronomy, Bahauddin Zakariya University , Multan , Pakistan.
Ahmad Naeem
AN
Shahzad
Institute of Agricultural Sciences, University of the Punjab , Lahore , Pakistan.
Hafiz Azhar Ali
HA
Khan
Institute of Agricultural Sciences, University of the Punjab , Lahore , Pakistan.
Moazzam
M
Anees
Institute of Agricultural Sciences, University of the Punjab , Lahore , Pakistan.
Muhammad Saleem
MS
Haider
Department of Environmental Science, Lahore College for Women University , Lahore , Pakistan.
Ammara
A
Fatima
Biomass; Brassica; Cabbage; Copper; Cu contamination; Hydroponics; Leaf chlorosis; Non-protein thiol; Nutrient uptake; Sulfur; Thiols; Toxicity