EVALUATION OF THE OXIDATIVE STRESS IN SUSPENSION OF PLANT CELLS

GUSTAVO GABRIEL MARTOS; DÍAZ RICCI, JUAN CARLOS

Jornada; XXXVIII Jornadas Científicas de la Asociación de Biología de Tucumán; 2011

Universidad Nacional de Tucumán

Plants under biotic or abiotic stress react producing a series of biochemical reactions that can lead to a defense response. The measure and kinetics of reactive oxygen species (ROS), such as hydrogen peroxide (H2O2), are very useful tools in the study of defense reponse in plants. In this work, we present a system to study intracell levels of H2O2 in plant cell suspensions. Mesophyll cells of strawberry plants (Fragaria x ananassa) Pájaro variety, of 8 weeks old, were used. 1,5 g of leaves were washed, cut into squares, and homogenized in a potter with 10 mL of buffer W5. The cells were recovered by differential centrifugation. The level of H2O2 was measured by fluorometry and cellular viability was determined with Blue Evans dye. The suspension (1,5 x 106 cell/mL) was evaluated during 24 hours. The initial level of H2O2 decreased approximately 65% after an overnight in the dark at 25°C and celullar viability decreased 8% 24 hs after extraction. The system was induced with Paraquat (0,1 mM) showing a peak of H202 3 hours after the induction. A system induced in the same way but with a previous 30 minute treatment with ascorbic acid (5 mM) exhibited lower values than the control. These results let us conclude that the developed system of cellular suspension constitutes a useful method for the study of stress in plants.