Oxidative conditions induces the electrical breakdown of Plant Lipid Membranes: implications in signaling and death processes during stress response

CORVALÁN, NATALIA A.; FELSZTYNA, IVÁN; CAVIGLIA, AGUSTÍN; ENET, ALEJANDRO; LASCANO, HERNÁN RAMIRO

Córdoba

Congreso; XXXII Reunión Argentina de Fisiología Vegetal; 2018

Sociedad Argentina de Fisiología Vegetal

Cell membrane systems, whose integrity is crucial to the plant physiology, are one of the maintargets of oxidative processes mediated by ROS. These chemical species interact with unsaturatedfatty acids of membrane lipids triggering a peroxidation chain reaction that involves the formationof lipid radicals (RO?, ROO?), lipid hydroperoxides (ROOH) and a variety of breakdown products ina process known as lipoperoxidation (LPO), which is re-initiated and propagated by redox-cyclingin the presence of transition metal ions. Even though the chemical reactions leading the oxidativedamage of cell membranes are well known, its effects on the functionality and the physicalproperties of the membrane remain poorly understood. In the present work, a thorough analysisof the electro-biophysical parameters of lipid bilayers composed of purified lipids from PlasmaMembrane of soybean leaves (Glycine max L) is performed under different oxidative conditions.Our preliminary results show that oxidative stress (1) induces nonlinear behavior (transitions) ofelectrical properties (Capacitance, Resistance and Conductance) dependent on ROS concentrationthresholds and ROS exposure-time; and (2) favors the Reversible Electrical Breakdown of themembrane as a part of an excess energy dissipation mechanism (EEDM), which could have acritical role during oxidative burst in stress response.