THE VEGETAL DEFENSE INDUCING ACTIVITY OF HET DEPENDS ON ITS REDOX STATE

MARTOS, G.G.; TOMAS GRAU, RODRIGO H; DÍAZ RICCI, JUAN C.

Tafí del Valle. Tucumán

Jornada; 35º Jornadas Científicas de la Asociación de Biología de Tucumán.; 2018

Asociación de Biología de Tucumán

It was previously reported that the ellagitannin HeT, obtained from strawberry leaves, has antibacterial properties and is also an inducer of the plant defense response. It was also shown that the antibacterial activity is due to a strong interaction with the plasma membrane that affects the flow of electrons and causes the oxidation of the HeT molecule. In this work we investigated whether, as with bacteria, HeT is oxidized by the interaction with plant cell, and if the redox state of HeT influences its activity as an inducer of plant defense. First, tests were carried out by UVVis spectroscopy where it was demonstrated that the interaction of HeT with isolated strawberry cells causes the oxidation of HeT. Subsequently, biochemical, molecular and phytopathological tests were carried out with HeT in the reduced state (HeT-red) and in the oxidized state (HeT-ox), in order to study the relationship between the capacity to induce the defense and the redox state of the molecule. The results obtained showed that the isolated strawberry cells treated with HeT-red produced a biphasic accumulation of H2O2 with peaks at 2 and 5 hours post treatment, whereas in the cells treated with HeT-ox there was no accumulation at all. In the same way, molecular studies showed that only HeT-red is able to induce over expression of the genes: FaCAT, FaAPX, FaPR1, FaChi2-2, FaERS1 and FaETR1 associated with the activation of the immune response in strawberry plants. Finally, a phytopathological test was carried out where it was demonstrated that only HeT-red is able to induce a protective effect in strawberry plants against the virulent pathogen Colletotricum acutatum.