BENÍCIO; http://lattes.cnpq.br/8012347991452670; BENÍCIO, Danniely Alves.
Résumé:
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.
