Glutathione-mediated Antioxidative Mechanisms in Sunflower (<Emphasis Type="Italic">Helianthus Annuus</Emphasis> L.) Cells in Response to Cadmium Stress |
| |
Authors: | Email author" target="_blank">Susana M?GallegoEmail author Marcelo J?Kogan Claudia E?Azpilicueta Clara?Pe?a María L?Tomaro |
| |
Institution: | (1) Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, Argentina |
| |
Abstract: | Cadmium (Cd) homeostasis and detoxification in sunflower (Helianthus annuus L.) cells differing in Cd sensitivity/tolerance were studied by analyzing the glutathione-mediated antioxidant mechanism
vis-à-vis phytochelatin biosynthesis in vitro. Calluses exposed to Cd-shock/-acclimatization (150μM) were assayed for oxidative stress, reduced glutathione (GSH), glutathione
disulfide (GSSG), phytochelatins (PCs) and reactive oxygen species (ROS). Although Cd did not induce any oxidative stress
in Cd-tolerant callus (TCd), it generated oxidative stress in Cd-shock callus (SCd) both in terms of lipid peroxidation and
protein oxidation. GSH/GSSG ratio remained similar to control values in the cadmium-acclimatized calluses. However, after
acute treatment, there was a decline in both GSH and GSSG levels in SCd with concomitant reduction in the GSH/GSSG ratio.
Analysis of PCs was performed using HPLC and mass spectrometry methods. PC concentration in TCd were approximately twice those
that in SCd, showing in both cases a 1:2:1 relative proportion for PC n = 2 (PC2): PC n = 3 (PC3): PC n = 4 (PC4). Calluses growing in the presence of Cd developed an increased resistance to paraquat oxidative stress generation.
These results indicated that PCs synthesis was an important mechanism for Cd detoxification in sunflower calluses, but the
capacity to grow in the presence of Cd is related to the tissues ability to maintain high intracellular levels of GSH. |
| |
Keywords: | Antioxidants Cadmium Glutathione Glutathione disulfide Helianthus annuus L Lipid peroxidation Phytochelatins Protein oxidation Reactive oxygen species Sunflower |
本文献已被 SpringerLink 等数据库收录! |
|