The present invention relates generally to the field of molecular biology and concerns a method for improving various economically important growth characteristics in plants. More specifically, the present invention concerns inter alia a method for modifying growth characteristics in plants by modulating expression in a plant of a nucleic acid encoding a HUB1 (Histone Monoubiquitination 1) polypeptide or encoding another protein useful in the methods of the present invention. The modified growth characteristics comprise a modification of light regulated phenotypes, such as modified circadian clock and/or circadian clock responses, or modified plant architecture.