ABSTRACT
Taking the cutting seedlings of grape variety 'Ze-xiang' as test materials, a hydroponic experiment was conducted to study the generation patterns of endogenous nitric oxide (NO) and reactive oxygen species (ROS) in their roots and leaves, and the changes of root MDA content and root activity under the stress of cadmium chloride (CdCl2). In the treatments 0-1 mmol x L(-1) of CdCl2, the NO content and NOS activity in roots and leaves and the root activity all presented a tendency of increasing first and decreasing afterwards with increasing CdCl2. At 0.01 mmol L(-1) of CdCl2, the NO content and NOS activity in roots increased by 51% and 63%, respectively; but at >0.1 mmol L(-1) of CdCl2, they decreased significantly. At 0.01 and 0.05 mmol x L(-1) of CdCl2, the leaf NO content and NOS activity had the greatest increase; at 0.5 and 1.0 mmol x L(-1) of CdCl2, the root O2 generation rate and H2O2 and MDA contents increased significantly. At the same concentrations of CdCl2, the O2 generation rate in leaves was much lower while the H2O2 content was much higher, compared with those in roots.
Subject(s)
Cadmium Chloride/toxicity , Nitric Oxide/biosynthesis , Plant Roots/metabolism , Reactive Oxygen Species/metabolism , Vitis/metabolism , Plant Leaves/metabolism , Seedlings/metabolism , Stress, PhysiologicalABSTRACT
This paper studied the fatty acid composition, reactive oxygen species (ROS), lipoxygenase (LOX) activity, and malondialdehyde (MDA) content in the leaves and roots of Malus hupehensis seedlings under effects of cadmium (Cd) stress. Noticeable changes were observed in the kinds and relative contents of fatty acids after treated with CdCl2 for 7-12 hours. The relative contents of unsaturated fatty acids in leaves and roots reached the maximum after treated for 7 hours, being 82. 82% and 72. 43% , respectively. The kinds of fatty acids in leaves increased from 11 to 14 after treated for 12 hours, while those in roots increased from 4 to 6 after treated for 17 hours. The O2* generation rate and the H2O2 content reached the maximum after treated for 3 and 7 hours, respectively, and the MDA content and LOX activity increased with treating time. Cd stress altered the fatty acid composition of Malus hupehensis via the inducement of reactive oxygen species and lipoxygenase, and induced lipid peroxidation, which was caused by both ROS and LOX within the first 12 hours of CdCl2 treatment and mainly by the increase of LOX activity since then.
Subject(s)
Cadmium/toxicity , Fatty Acids/metabolism , Lipid Peroxidation/drug effects , Malus/metabolism , Stress, Physiological , Fatty Acids/chemistry , Lipoxygenase/metabolism , Malus/chemistry , Malus/drug effects , Reactive Oxygen Species/metabolism , Soil Pollutants/toxicityABSTRACT
Taking the one-year cutting-seedlings of four grape cultivars (Kyoho, Muscat Hamburg, Long Yan, and Ze Xiang) as test materials, their root mitochondrial hydrogen peroxide (H2O2) content, membrane permeability transition pore (MPTP), membrane potential (Deltapsi), cytochrome C (Cyt c) content, and root activity were measured under effects of CdCl2. For all test grape cultivars, the root mitochondrial H2O2 content and MPTP increased, but the Deltapsi, Cyt c content, and root activity decreased after treated with 0.5 mmol CdCl2 x L(-1). The mitochondrial H2O2 content and Cyt c content were in the sequence of Kyoho > Ze Xiang > Muscat Hamburg > Long Yan, while the root activity, MPTP, and Deltapsi were in adverse, i.e., Long Yan > Muscat Hamburg > Ze Xiang > Kyoho. Among the test grape cultivars, the root activity of Kyoho was easier to be inhibited under Cd stress, while that of Long Yan was least affected by CdCl2.
