Salicylic acid as modulator of Cd toxicity in soybean plants

SANTA- CRUZ DM; ZILLI CG; CAGGIANO E; LÓPEZ LECUBE M; ROMANELLO M; NORIEGA GO; TOMARO ML; BALESTRASSE KB

Puerto Madryn

Congreso; 46th Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2010

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

<!-- @page { size: 21cm 29.7cm; margin: 2cm } P { margin-bottom: 0.21cm } A:link { color: #0000ff } --> In this study, the possibility of enhancing Cd stress tolerance of soybean plants (Glycine max L.) by exogenous application of salicylic acid (SA) was investigated. Salicilic acid was applied in the Hoagland solution at various concentrations ranging from 62 to 500 µM for 48 h. After SA pre-treatment, plants were subjected to 25µM Cd for 5 days. Our results showed that 125 µM SA provided significant protection against Cd compared to controls, diminishing TBARS levels (40%) and increasing GSH content (36%) respect to Cd treated plants. Pre-treatment with 125 µM SA did no elevate catalase (CAT) activity, but enhanced heme oxygenase-1 (HO-1) (24%) activity and gene expression. These findings indicate that HO-1 acts not only as the rate limiting enzyme in heme catabolism, but also as an antioxidant enzyme. Results show that SA, which is a well known phenolicphytohormone with roles in plant growth and development, could be used effectively to protect soybean plants from the damaging effects of Cd pollution in soils by promoting heme catabolism leading to the production of the highly antioxidant biliverdin and carbon monoxide, without any adverse effect on the plant growth.