Análise do perfil enzimático da catalase em plântulas de Anadenanthera colubrina (Vell.) Brenan sob condições de estresse oxidativo.

Abstract

On the adverse environmental conditions, plants suffer different kinds of stress promoted by various factors, biotic and abiotic. By the way, these situations discharge plant defense mechanisms to keep the cell homeostasis. An example of stress suffered by the plants is oxidative stress that produces certain compounds named ROS, reactive oxygen species.On this situation, defense molecules are activated such as antioxidant enzymes. One of them is catalase, which has the function to degradete the oxygen peroxide in water and oxygen. The aim of this work was evaluate the effect of oxygen peroxide in seedlings of Anadenanthera colubrine (Vell.) Brenan grown in two different substrates, Germitest® paper and sterile sand. The activity of the catalase enzyme in challenged plants with peroxide solutions in 0 mM, 2.5 mM, 5.0 mM, 7.50 mM, 10.0 mM was measured. Equally the soluble protein concentration in leave tissue was determined. In the system based on paper grown, the percentual of grown (91.68%) was higher than the sand system-based (76.50%). Statistical differences were observed between sand system and paper one (t paired test, p<0,05).The water lost during the stress period for all treatments was high, after 48 hours. No statistical differences were observed for the concentration of extracted proteins for both systems (sand and paper, ANOVA, p>0,05). The SDS-PAGE for seedlings grown in sand showed specific bands at the concentrations of 2.5 and 5.0 mM. The catalase activity for the treatments mentioned increased in comparison with the control group and the highest activity was observed for 5.0 mM concentration. In conclusion, 5.0mM concentration for seedlings grown in sterile sand induced catalase activity increased. For this treatment specific bands were observed in SDS-PAGE, probably proteins related to oxidative stress. Finally, we could suggest the sand system as appropriate to studying defense plant.