Akademik Veri Yönetim Sistemi
SCIENTIA HORTICULTURAE, cilt.137, ss.81-86, 2012 (SCI-Expanded)
Since bromine is toxic to plants and humans, understanding plant responses to excess bromine is essential, and there is a need to know possible physiological mechanisms for the avoidance of Br-induced stress. Therefore, we investigated bromine-induced oxidative stress in carrot under glasshouse conditions in response to application of bromate and chloride. Five levels of Br (0, 0.125, 0.25, 0.50 and 1.00 mmol kg(-1) as KBrO3) and three levels of Cl (0, 10 and 20 mmol kg(-1) as KCl) were applied to soil-grown plants. Shoot dry weight of carrot was reduced with the highest level of applied Br, and both shoot and storage root dry weights were also reduced by the applied Cl. Low rates of application of Br gave higher total chlorophyll and carotenoid concentrations, but higher levels of applied Br significantly reduced both total chlorophyll and carotenoids. Accumulation of malondialdehyde (MDA, an indicator of lipid peroxidation) and H2O2 was significantly increased by Br treatments, as were activity of the antioxidant enzymes catalase (CAT) and ascorbate peroxidase (APX). There was no clear change in activity of superoxide dismutase (SOD) in response to Br. Chloride treatments did not appear to lower the activity of the antioxidant enzymes, but gave increased concentrations of H2O2 (although not MDA). Total bromine concentrations of the shoots and storage roots were significantly increased by increasing levels of Br supply, although Cl supply noticeably decreased them. Based on the present work, it can be concluded that applied Br caused oxidative stress and membrane damage in carrot plants. However, applied Cl levels in this work did not prevent oxidative damage, but significantly reduced Br concentrations in the shoots and storage roots. (C) 2012 Elsevier B.V. All rights reserved.