Method for modifying plant morphology, biochemistry and physiology

A method for stimulating root growth or for enhancing the formation of lateral or adventitious roots or for altering root geotropism comprising expression of a nucleic acid encoding a plant cytokinin oxidase selected from the group consisting of:

• a. nucleic acids comprising a DNA sequence as given in any of SEQ ID NOs:27, 1, 3, 5, 7, 9, 11, 25, 26, 28 to 31, 33 or 34, or the complement thereof,
• b. nucleic acids comprising the RNA sequences corresponding to any of SEQ ID NOs:27, 1, 3, 5, 7, 9, 11, 25, 26, 28 to 31, 33 or 34, or the complement thereof,
• c. nucleic acids specifically hybridizing to any of SEQ ID NOs:
• 27, 1, 3, 5, 7, 9, 11, 25, 26, 28 to 31, 33 or 34, or to the complement thereof,
• d. nucleic acids encoding a protein comprising the amino acid sequence as given in any of SEQ ID NOs:
• 2, 4, 6, 8, 10, 12, 32 or 35, or the complement thereof,
• e. nucleic acids as defined in any of (a) to (d) characterized in that said nucleic acid is DNA, genomic DNA, cDNA, synthetic DNA or RNA wherein T is replaced by U,
• f. nucleic acid which is degenerated to a nucleic acid as given in any of SEQ ID NOs:27, 1, 3, 5, 7, 9, 11, 25, 26, 28 to 31, 33 or 34, or which is degenerated to a nucleic acid as defined in any of (a) to (e) as a result of the genetic code,
• g. nucleic acids which are diverging from a nucleic acid encoding a protein as given in any of SEQ ID NOs:
• 2, 4, 6, 8, 10, 12 or 35 or which is diverging from a nucleic acid as defined in any of (a) to (e), due to the differences in codon usage between the organisms,
• h. nucleic acids encoding a protein as given in SEQ ID NOs:
• 2, 4, 6, 8, 10, 12 or 35 or nucleic acids as defined in (a) to (e) which are diverging due to the differences between alleles,
• i. nucleic acids encoding a protein as given in any of SEQ ID NOs:
• 2, 4, 6, 8, 10, 12 or 35,
• j. functional fragments of nucleic acids as defined in any of (a) to (i) having the biological activity of a cytokinin oxidase, and
• k. nucleic acids encoding a plant cytokinin oxidase, or comprising expression, preferably in roots, of a nucleic acid encoding a protein that reduces the level of active cytokinins in plants or plant parts.

An isolated nucleic acid encoding a plant protein having cytokinin oxidase activity selected from the group consisting of:

• a. a nucleic acid comprising a DNA sequence as given in any of SEQ ID NOs:
• 29, 3, 5, 9, 26, 27, 31, 33 or 34, or the complement thereof,
• b. a nucleic acid comprising the RNA sequences corresponding to any of SEQ ID NOs:
• 29, 3, 5, 9, 26, 27, 31, 33 or 34, or the complement thereof,
• c. a nucleic acid specifically hybridizing to a nucleic acid as given in any of SEQ ID NOs:
• 29, 3, 5, 9, 26, 27, 31, 33 or 34, or the complement thereof,
• d. a nucleic acid encoding a protein with an amino acid sequence comprising the polypeptide as given in SEQ ID NO:
• 32 and which is at least 70% similar to the amino acid sequence as given in SEQ ID NO:
• 4,
• e. a nucleic acid encoding a protein with an amino acid sequence which is at least 47% similar to the amino acid sequence as given in SEQ ID NO:
• 6,
• f. a nucleic acid encoding a protein with an amino acid sequence which is at least 47% similar to the amino acid sequence as given in SEQ ID NO:
• 10 or 35,
• g. a nucleic acid encoding a protein comprising the amino acid sequence as given in any of SEQ ID NOs:
• 4, 6, 10, 32 or 35,
• h. a nucleic acid which is degenerated to a nucleic acid as given in any of SEQ ID NOs:
• 29, 3, 5, 9, 26, 27, 33 or 34 or which is degenerated to a nucleic acid as defined in any of (a) to (g) as a result of the genetic code,
• i. a nucleic acid which is diverging from a nucleic acid encoding a protein as given in any of SEQ ID NOs:
• 4, 6, 10 or 35 or which is diverging from a nucleic acid as defined in any of (a) to (g) due to the differences in codon usage between the organisms,
• j. a nucleic acid encoding a protein as given in SEQ ID NOs:
• 4, 6, 10 or 35, or a nucleic acid as defined in (a) to (g) which is diverging due to the differences between alleles,
• k. a nucleic acid encoding an immunologically active fragment of a cytokinin oxidase encoded by a nucleic acid as given in any of SEQ ID NOs:
• 29, 3, 5, 9, 26, 27, 31, 33 or 34, or an immunologically active fragment of a nucleic acid as defined in any of (a) to (j),
• l. a nucleic acid encoding a functional fragment of a cytokinin oxidase encoded by a nucleic acid as given in any of SEQ ID NOs:
• 29, 3, 5, 9, 26, 27, 31, 33 or 34, or a functional fragment of a nucleic acid as defined in any of (a) to (j), wherein said fragment has the biological activity of a cytokinin oxidase, and
• m. a nucleic acid encoding a protein as defined in SEQ ID NO:
• 4, 6, 10 or 35, provided that said nucleic acid is not the nucleic acid as deposited under any of the following Genbank accession numbers:
• AC005917, AB024035, and AC023754.