Heme oxygenase contributes to alleviate salinity damage in Glycine max L. leaves

CARLA ZILLI; DIEGO SANTA CRUZ; GUSTAVO YANNARELLI; GUILLERMO NORIEGA; MARIA TOMARO; KARINA BALESTRASSE

International Journal of Cell Biology

Hindawi Publishing Corporation

Año: 2009 vol. 2009 p. 1 - 9

1687-8876

Plants are frequently subjected to different kind of stress, such as salinity and, like other organisms, they have evolved strategies for preventing and repairing cellular damage caused by salt stress. To assess salinity-induced toxicity in plants, we performed experiments focusing on the metabolic adaptation of soybean plants (Glycine max L.) to NaCl-induced oxidative stress. Plants were cultured in Hoagland solution and subjected to different NaCl concentrations (0-200 mM) for 10 days. Afterwards, leaves were harvested for analysis. Treatments with 100 and 200 mM NaCl induced ion leakage and lipid peroxidation augmentation, loss in chlorophyll content and accumulation of O2- and H2O2. However, 50 mM NaCl did not modify these parameters, which remains similar to control values. To understand the biochemical responses to salinity, activities and gene expressions of antioxidant enzymes, such as catalase (CAT) and superoxide dismutase (SOD) were assayed. CAT and SOD activities and gene expressions were increased under 100 mM NaCl, while no differences were observed respect to controls under 50 mM salt. Treatment with 200 mM NaCl caused a diminution in both enzyme activities and gene expressions. Similar results were obtained when heme oxygenase (HO-1) activity, protein and gene expression were measured. To evaluate the involvement of HO-1 in the protection against salinity, experiments were carried out in the presence of Zn-protoporphyrin IX (ZnPPIX), a potent HO activity inhibitor. Results here reported let us conclude that HO plays a leading role in the defense mechanisms against salinity.