title: The role of salicylic acid in the prevention of oxidative stress elicited by cadmium in soybean plants.
abstract: The protective action of salicylic acid (SA) pre-treatment on soybean plants before cadmium (Cd) addition was tested. Oxidative stress parameters, such as TBARS formation, glutathione and chlorophyll content, were altered by Cd, instead no differences were observed in plants only pre-treated with SA. Antioxidant enzymes were affected by Cd treatment, while SA protected against these effects. These findings indicated that SA could act as a protector against oxidative stress induced by Cd. Taking into account the fact that heme-oxygenase-1 (HO-1) has been previously described as a novel antioxidant enzyme, experiments were carried out to determine whether it was involved in the protection exerted by SA. As expected, Cd brought about an enhancement of 57 % in HO-1 activity and 150 % in protein content (150 %), SA also increased both the enzyme activity and its protein content (28 and 75 %, respectively). Surprisingly, the observed rise of HO activity and protein content under SA treatment was lower than that produced by Cd alone. These lower values indicated, that HO-1 could not be directly involved in the protection of SA against Cd effects. In order to shed light in the mechanisms involved in SA effects, Cd content was determined in the tissues of Cd treated plants with and without SA pre-treatment. Results indicated that, in the presence of SA, Cd uptake was inhibited, thus avoiding its deleterious effects. Moreover, the observed HO-1 activity enhancement by SA indicates that this phytohormone could be engaged in the signalling pathway of heme degradation.
authors.affiliation: Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET, Buenos Aires, Argentina.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Noriega
authors.forename: Ethel
authors.initials: E
authors.lastname: Caggiano
authors.forename: Manuel López
authors.initials: ML
authors.lastname: Lecube
authors.forename: Diego Santa
authors.initials: DS
authors.lastname: Cruz
authors.forename: Alcira
authors.initials: A
authors.lastname: Batlle
authors.forename: María
authors.initials: M
authors.lastname: Tomaro
authors.forename: Karina Beatriz
authors.initials: KB
authors.lastname: Balestrasse
mesh_terms: D002104:Cadmium / Q000494:pharmacology*; D051547:Heme Oxygenase-1 / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D020156:Salicylic Acid / Q000494:pharmacology*; D013025:Glycine max / Q000187:drug effects* / Q000378:metabolism
chemical_list: D002104:Cadmium; D051547:Heme Oxygenase-1; D020156:Salicylic Acid