A transgenic plant transformed by a Dof transcription factor, OBP3, coding nucleic acid, wherein expression of the nucleic acid sequence in the plant results in an alteration in the size of the resulting plant as compared to a corresponding wild-type variety of plant. Also provided are agricultural products, including seeds, produced by the transgenic plants. Further provided are isolated OBP3's, isolated nucleic acid coding OBP3's, and vectors and host cells containing the latter.