Salicylic acid increases tolerance to oxidative stress induced by hydrogen peroxide accumulation in leaves of cadmium-exposed flax
The aim of this study is to investigate the impacts of exogenous salicylic acid (SA) pretreatments on hydrogen peroxide (H2O2) accumulation, protein oxidation, and H2O2-scavenging enzymes in leaves of Cd-treated flax seedlings. Cdenhanced H2O2 levels were related to increased activities of guaiacol peroxidase (POX, EC 1.11.1.7) and ascorbate peroxidase (APX, EC 1.11.1.11), and were independent of changes in catalase (CAT, EC 1.11.1.6) and superoxide dismutase (SOD, EC 1.15.1.1) activities. In control flax seedlings, exogenous SA pretreatments inhibited the activity of CAT, resulted in an enhanced production of H2O2 suggesting that SA requires H2O2 to initiate an oxidative stress. However, although leaves of Cd-free flax seedlings pretreated with SA accumulated in vivo H2O2 by 1.2-fold compared with leaves of Cd-only exposed ones; the damage to growth and proteins after the exposure to Cd was significantly less, indicating that SA can regulate the Cd-induced oxidative stress. Moreover, the Cd-treated seedlings primed with SA exhibited a higher level of total antioxidant capacities and increased activities of H2O2-detoxifying enzymes.
Main Authors: | , , , , , , |
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Other Authors: | |
Format: | artículo biblioteca |
Language: | English |
Published: |
Taylor & Francis
2014
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Subjects: | Cadmium, Salicylic acid, Hydrogen peroxide, Antioxidant enzymes, |
Online Access: | http://hdl.handle.net/10261/101892 http://dx.doi.org/10.13039/501100007521 |
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Summary: | The aim of this study is to investigate the impacts of exogenous salicylic acid (SA) pretreatments on hydrogen peroxide (H2O2) accumulation, protein oxidation, and H2O2-scavenging enzymes in leaves of Cd-treated flax seedlings. Cdenhanced H2O2 levels were related to increased activities of guaiacol peroxidase (POX, EC 1.11.1.7) and ascorbate peroxidase (APX, EC 1.11.1.11), and were independent of changes in catalase (CAT, EC 1.11.1.6) and superoxide
dismutase (SOD, EC 1.15.1.1) activities. In control flax seedlings, exogenous SA pretreatments inhibited the activity of
CAT, resulted in an enhanced production of H2O2 suggesting that SA requires H2O2 to initiate an oxidative stress.
However, although leaves of Cd-free flax seedlings pretreated with SA accumulated in vivo H2O2 by 1.2-fold compared with leaves of Cd-only exposed ones; the damage to growth and proteins after the exposure to Cd was significantly less, indicating that SA can regulate the Cd-induced oxidative stress. Moreover, the Cd-treated seedlings primed with SA exhibited a higher level of total antioxidant capacities and increased activities of H2O2-detoxifying enzymes. |
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