The present invention relates generally to the field of molecular biology and concerns a method for improving plant growth characteristics. More specifically, the present invention concerns a method for improving plant growth characteristics by modulating expression in a plant of a plant nucleic acid encoding a cyclin dependent kinase (CDK) and/or by modulating activity in a plant of a plant CDK protein, which CDK protein comprises different motifs or which CDK nucleic acid encodes such protein. The present invention also concerns plants having modulated expression of a plant CDK nucleic acid and/or modulated activity of a plant CDK protein, which CDK protein comprises different sequence motifs or which nucleic acid encodes such protein and which plants have improved growth characteristics relative to corresponding wild type plants. The invention additionally relates to specific nucleic acid sequences encoding for the aforementioned proteins having the aforementioned plant growth improving activity, nucleic acid constructs, vectors and plants containing said nucleic acid sequences.
