E2F TRANSCRIPTION FACTORS ROLE IN THE DEVELOPMENT OF Arabidopsis thaliana PLANTS UNDER UV-B RADIATION

MA. LORENA FALCONE FERREYRA; MA. SOL GOMEZ; PAULA CASATI

Buenos Aires

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

Plant development involves the production of new cells that arise at the meristems from divisions of pluripotent stem cells, followed by their successive cell cycle exit and differentiation. In particular, cell division is a tightly regulated process that is influenced by innate genetic cues as well as by external environmental signals. The Retinoblastoma E2F pathway plays an important role in the regulation of the cell cycle and in different differentiation processes. UV-B radiation negatively affects cell proliferation and development; thus, we analyzed the effect of this radiation in different Arabidopsis thaliana mutants and transgenic lines with altered expression of genes encoding E2F transcription factors. In this work, we analyzed the role of E2Fb, a transcriptional activator which regulates the E2Fe expression, among many others genes. Previous reports have shown that E2Fe is a transcriptional repressor of the photolyase PHR1, and plants knocked out in the E2Fe gene are more tolerant to UV-B radiation. Through phenotypic analysis, microscopy observations and molecular biology experiments carried out using plants exposed to UV-B radiation, we show that mutant plants in the E2Fb gene are less sensitive to this radiation than wild type plants. For example, these mutants show a lower decrease in the rosette and leaf area than wild type plants. Together, our data demonstrate that E2Fb participates in UV-B responses in Arabidopsis and it may regulate the expression of genes involved in the cell cycle checkpoints.