CONICET | Buscador de Institutos y Recursos Humanos

Prosopis strombulifera (Lam.) Benth. is a halophytic shrub abundant in high-salinity areas in central Argentina, with high tolerance against NaCl but strong growth inhibition by Na2SO4. In the present study, the modulation of the antioxidant systems (enzymatic and non-enzymatic components) was analyzed in P. strombulifera plants grown in hydroponic culture under different salt treatments (NaCl, Na2SO4 and the iso-osmotic mixture). P. strombulifera plants growing under Na2SO4 treatment showed strong indications of oxidative stress, with increases in both H2O2 and O2-?. Modifications in antioxidant enzymes activities were observed mainly under Na2SO4 treatment, where CAT seems to plays an important role in early detoxification of H2O2 in roots, whereas SOD and APX have a predominant role in leaves. As part of the non-enzymatic system, phytochemicals profile was analyzed in leaves and 23 compounds were identified, being polyphenols the most abundant. Control plants presented the major variety of phytochemicals (14). Na2SO4-treated plants presented 10 compounds and NaCl-treated plants 9 compounds, but with a different profile. NaCl-treated plants showed the highest antioxidant capacity. Our findings confirm that different types of salt treatments provoke a differential modulation of the antioxidant systems. Polyphenols and other ROS-detoxifying compounds, in a joint action with the enzymatic antioxidant system, are proposed to have a fundamental role in the cellular protection of P. strombulifera plants under severe oxidative stress. Our findings also highlight the potential of this halophyte as a valuable source of bioactive compounds with high antioxidant activity and health benefits.