FB1-induced phytotoxicity: redox state of different intracellular compartments and their correlation with autophagy

OTAIZA GONZÁLEZ, SANTIAGO NICOLÁS; ENET, ALEJANDRO; ROBERT, GERMÁN; THEUMER, MARTIN GUSTAVO; LASCANO, H. RAMIRO

Santa Fe

Congreso; XXXIII Argentinian meeting of Plant Physiology; 2021

Sociedad Argentina de Fisiología Vegetal

Mycotoxin FB1 is an important pathogenicity factor in the Fusarium verticillioides-plant interaction and alone induces many of the phytopathological signs observed in infection. The aim of the work was to correlate the role of autophagy and redox changes in different intracellular compartments in a model of acute phytotoxicity induced by FB1.Arabidopsis Col-0, atg7 mutant seedlings were grown with FB1 (0-1 µM). At 7 days after planting, cell death was determined by electrolyte leakage (EL) and ratiometric redox-sensitive GFP (roGFP) expressed in different compartments (cytoplasm, mitochondria, peroxisome and chloroplast) of the plant, were observed by confocal microscope and analyzed with FIJI ImageJ software.FB1 induced different EL profile in atg7 with respect to Col-0 (decrease and increase at low and high concentrations of FB1, respectively). Also, a different oxidation level was observed in the cytoplasm in atg7 at 0.1 µM (decrease) and 1 µM (increase) of FB1 with respect to Col-0.Our preliminary results suggests that autophagy induces death at low concentrations of FB1 and inhibition at high concentrations of the mycotoxin. Likewise, cell death is correlated with a higher level of oxidation in the cellular cytoplasm.