ROLE OF E2FC TRANSCRIPTION FACTOR DURING THE UV-B RESPONSES IN Arabidopsis

MARÍA SOL GOMEZ; MA LORENA FALCONE FERREYRA; PAULA CASATI

Congreso; LIV Reunión SAIB 2018; 2018

Plants are normally exposed to a constantly changing environment, which influences the developmental programs executed throughout theirlifetime. Solar radiation is one of the most important environmental factors affecting plant growth, but its spectrum includes UV-B radiation, ahigh-energy component to which plants need to adapt. High UV-B intensities induce damage responses in plants, affecting cell cycle anddevelopment. Inhibition of leaf growth is one of the most consistent responses. The Retinoblastoma-E2F pathway (RBR/E2F/DP) plays animportant role in the regulation of the cell cycle and in several differentiation processes. In this work, we particularly analyzed the role of E2Fc,one of the six E2F transcription factors in Arabidopsis, in the response after high UV-B radiation. This transcription factor acts as a repressor ofcell proliferation and is a positive regulator of the endoreduplication onset. For this purpose, we analyzed the effect of UV-B light in thedevelopment of Arabidopsis thaliana transgenic lines with altered expression of E2Fc. By phenotypic studies and microscopic analysis in leavesand roots, together with molecular biology experiments, we show that E2Fc regulates the inhibition of cell proliferation at UV-B intensities thatcause DNA damage. In addition, our results demonstrate that E2Fc regulates the expression of genes involved in the activation of programmedcell death without having a direct participation in DNA repair.