Ectopic Expression of E2FB, a Cell Cycle Transcription Factor, Accelerates Flowering and Increases Fruit Yield in Tomato

Cell division and plant development are two interconnected and dependent processes. Nowadays, the sequencing of plant genomes has allowed the identification of the majority of cell cycle regulators. However, the function of many of these cell cycle genes remains unclear. At present, the majority of cell cycle studies have been focused on the model plant Arabidopsis thaliana. In this model plant, the cell cycle transcription factor E2FB acts as positive regulator of cell proliferation. In this work we analyzed the effect of expressing E2FB in tomato. E2FB-expressing plants show reduced levels of cell cycle genes in mature leaves and grow and develop faster than wild type (wt). E2FB^OE plants flower significantly earlier than wt and produce more and bigger fruits, with the total fruit yield significantly higher in E2FB^OE than in wt plants. Taken together, our data indicate that the rate of cell proliferation and differentiation is important for tomato development and that cell cycle genes are good candidates to manipulate to improve crop productivity.