HO-1 involvement in the protection exerted by salicylic acid in Cd treatment in soybean plant

NORIEGA GO; CAGGIANO E; LOPEZ LECUBE M; SANTA CRUZ DM; TOMARO ML; BALESTRASSE KB

Edinburgo

Congreso; 7th International Meeting on Heme Oxygenases and Related Enzymes; 2012

University of Edinburgh

In higher plants, Cd promotes the accumulation of reactive oxygen species, causes severe damage to important cellular components, such as lipids, protein, DNA, and RNA, and leads to a decreased growth, roll and chlorosis of leaf, and root necroses. Salicylic acid (SA) is an endogenous growth regulator, which participates in physiological processes in plants, such as growth, photosynthesis, nitrate metabolism, ethylene production and flowering. SA is also known to be involved in abiotic stress signaling, including plant response to heavy metals. Aims. Experiments were carried out in order to elucidate the role of SA pre-treatment on HO-1 behaviour in Cd treated soybean plants.Methods and Results .Soybean plants were pretreated with different SA concentrations for 48 h before 5 days treatment with 50 µM Cd. We demonstrated that Cd brought about oxidative stress, measured as TBARS formation, GSH and chlorophyll contents, as well as, antioxidant enzymes such as , catalase, superoxide dismutase and guayacol peroxidase. Under these conditions HO-1 activity and protein content were increased (50%). Pre-treatment with SA prevented oxidative stress and provoked a lower enhancement in HO-1 activity and protein content (30%). Atomic absorption spectrometry indicated that Cd uptake is diminished in the presence of SA. Conclusions. These findings highlight on one hand, that SA inhibits Cd uptake and on the other hand enhances HO-1 activity and protein content in soybean plants.