HeT ellagitanin alters cell redox status and ROS accumulation in strawberry plants

MARTOS, GUSTAVO G.; MAMANí DE MARCHESE, MA. ALICIA; TOMAS GRAU, RODRIGO H; DíAZ RICCI, JUAN C.

Córdoba

Congreso; 52º Reunión Anual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular (SAIB).; 2016

SAIB

It was reported that strawberry leaves exposed to various biotic and abiotic factors accumulate a phenolic compound identifiedas 1-0galloyl-2,3;4,6-bis-hexahydroxydiphenoyl-â-D-glucopyranose (HeT) and that foliar applications of HeT increased resistance toward C. acutatum, responsible of anthracnose disease. In this paper we have investigated theearly cellular events that take place during the activation of the immune response of strawberry plants treated with HeT. Antiradical activity of HeT was confirmed in vitro showing that HeT acts as an antioxidant, scavenging superoxide radicals. A rapid decrease of the intracellular H2O2 in isolated mesophyll cells treated with HeT was observed 1 hour post treatment (hpt), suggesting that this effect may be due to the decrease of superoxide anion (substrate of the superoxide dismutase). Within vitro analysis it was also observed that HeT inhibits the activity of the enzymes catalase and peroxidase. The latter may explain the accumulation of H2O2 observed 4 hpt in strawberry plants treated with HeT. The addition of HeT to mesophyll cells also caused a rapid hyperpolarization of the plasmatic membrane, possibly due to the movement of ions through the membrane provoked by the alteration of the cell redox status. Finally, a quick accumulation of nitric oxide in the chloroplasts of cells treated with HeT was observed.