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

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

Córdoba

Congreso; XXXII Reunión Argentina de Fisiología Vegetal; 2018

Sociedad Argentina de Fisiología Vegetal - SAFV

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