Woody plants having improved growth properties

A method for producing a genetically modified woody plant having increased biomass and/or wood density compared to a corresponding non-genetically modified woody plant of the same species, said method comprising:

• a) transforming a woody plant cell with an expression cassette which comprises a nucleic acid molecule operably linked to a heterologous promoter and encoding at least one inhibitory polynucleotide that targets an endogenous gene sequence in the transformed woody plant cell to reduce or eliminate expression of a protein encoded by the endogenous gene sequence, wherein said at least one inhibitory polynucleotide is expressed in said transformed woody plant cell, and wherein said endogenous gene sequence encodes an endogenous polypeptide having an amino acid sequence selected from the group consisting of (i) the amino acid sequence as set forth in SEQ ID NO:
• 98 and (ii) an amino acid sequence having at least 95% amino acid sequence identity to the amino acid sequence as set forth in SEQ ID NO:
• 98, and overexpressing said inhibitory nucleic acid sequence in said transformed woody plant cell to produce genetically modified woody plant cell, and obtaining genetically modified woody plants and parts thereof having reduced or elimination of expression of said endogenous polypeptide as compared to a corresponding non-genetically modified woody plant of same species lacking said expression cassette;
• b) selecting a genetically modified woody plant and a part thereof from said genetically modified woody plants and parts thereof of step a) with improved biomass and/or wood density as compared to a corresponding non-genetically modified woody plant of the same species;
• and
• c) growing the genetically modified woody plant and the part thereof of step b) under conditions which permit development of the genetically modified woody plant.