Abstract: An isolated protein which exhibits cytokinin oxidizing activity selected from the group consisting of SEQ. ID No. 1, a protein having an amino acid sequence which includes the amino acid sequence of SEQ. ID No. 1, a protein having an amino acid sequence which includes a portion of the amino acid sequence of SEQ. ID No. 1, the included portion being at least about 20 amino acid residues in length and conferring the cytokinin oxidizing activity on the protein, and a protein including an amino acid sequence with at least about 65% sequence identity to SEQ. ID No. 1, the remainder of amino acid residues being conservatively substituted. Nucleic acids encoding proteins which exhibit cytokinin oxidizing activity and related products and methods are also disclosed.