Method of increasing expression of nucleic acid molecules in plants using multiple transcription units

A method of increasing expression of a nucleic acid molecule, the method comprising introducing into a plant or plant part a construct comprising three plant transcription units (PTU), each of said PTUs comprising components for enhancing expression of an operably linked nucleic acid molecule and where each PTU comprises the same maize globulin 1 seed promoter selected from the group consisting of SEQ ID NO:

• 1, SEQ ID NO:
• 2, SEQ ID NO:
• 5 and SEQ ID NO:
• 7 operably linked to a nucleic acid molecule encoding exo-β-1,4-glucanase (CBH1), assaying said plants or plant parts for expression of said CBH1 and selecting said plants or plant parts accumulating said CBH1 at levels at least 3 times higher than CBH1 produced in a plant or plant part comprising a single copy of said PTU, said single copy PTU consisting of the same components as each of said multiple PTUs.