TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Molecule: In the isolated nucleic acid molecule, the nucleic acid is cDNA or genomic DNA. The polypeptide preferably comprises or consists of an amino acid sequence comprising 334-467 amino acids (SEQ ID NO: not defined) given in the specification. The polypeptide is a variant polypeptide and comprises an amino acid sequence which has 60-70% amino acid sequence identity with the amino acid sequences comprising fully defined 334-467 amino acids (SEQ ID NO: not defined) given in the specification, which sequence has been modified by deletion, addition or substitution of at least one amino acid residue where the modification retains or enhances the glycosyl hydrolase enzyme activity of the polypeptide. The vector is adapted for the recombinant expression of the nucleic acid molecule. The promoter sequence is a senescence inducible promoter sequence. Preferred Cell: The isolated cell is preferably a eukaryotic cell or a fungal cell, where the fungal cell is Aspergillus spp, Neurospora spp, or Saccaromyces spp. The cell is preferably a plant cell. The cell is transfected with a further nucleic acid molecule where the nucleic acid molecule encodes a polypeptide that has phenol oxidase activity. The further nucleic acid molecule comprises: (a) a nucleic acid molecule comprising fully defined 1999-2044 bp (SEQ ID NO: not defined) given in the specification; (b) a nucleic acid molecule comprising nucleic acid sequences that hybridize to the sequence identified in (a) above under stringent hybridization and encodes a hemocyanin polypeptide with phenol oxidase activity; and (c) a nucleic acid molecule comprising nucleic acid sequences that are degenerate as a result of the genetic code to the nucleic acid sequence defined in (a) and (b). The further nucleic acid molecule encodes a protease that digests the hemocyanin polypeptide to provide a phenol oxidase polypeptide. The cell may also be a prokaryotic cell. Preferred Plant: The plant is a biomass crop, e.g. switchgrass, alfalfa, willow, poplar, eucalyptus, miscanthus, wheat, maize, or barley. Preferred Method: In preparing a plant biomass for saccharification, the transgenic plant material is further processed by saccharification to sugar. In preparing plant biomass for saccharification, the sugar is used as a feedstock in the production of ethanol by microbial fermentation. In recombinant production of a polypeptide, the cell is a bacterial cell. EXAMPLE - No suitable example given.