CATALASE RESPONSE IN ROOTS OF WHEAT PLANTS SUBJECTED TO ABIOTIC STRESS FACTORS

BARCIA R ; PENA LB; BENAVIDES MP; GALLEGO SM

Congreso; 46th Annual Meeting- XLVI Reunión Annual. Sociedad Argentina de Investigación en Bioquímica y Biología Molecular. SAIB.; 2010

SAIB

Adverse environmental growth conditions are related to oxidative stress production in plant cell. Catalase, CAT, (H2O2: H2O2 oxidoreductase; EC 1.11.1.6) is one of the most important antioxidant enzymes. It is found in all aerobic organisms and catalyses the dismutation of H2O2 to O2 and H2O. In Triticum aestivum (wheat) two genes codes for this enzyme: cat1 and cat2. In the present work we studied in which way CAT activity, isioforms and cat genes expression were affected by abiotic stress factors in wheat root. Treatments with 1 and 10 µM CdCl2, 0,5 µM paraquat (PQ), 1 mM H2O2 and water deprivation (22% polyethylene glycol, PEG) were performed using floating culture system. Cd2+, PQ and H2O2 decreased specific CAT enzyme activity (15, 20, 26 and 10% for 1 and 10 µM Cd2+, 0,5 µM PQ, 1 mM H2O2 respectively respect to control values). On the other hand, water deficit increase absolute CAT activity, but this increment is related to an increment in root protein content. Two bands of CAT activity were detected in native PAGE. No modification in the number of isoform was detected in root of treated plants respect to control. Nevertheless cat1 and cat2 gene expression were modified by treatments. Taken together all these result indicate that catalase is an enzyme sensitive to abiotic stress factors and that its regulation has high degree of complexity.