This disclosure concerns compositions and methods for promoting transcription of a nucleotide sequence in a plant or plant cell, employing a minimal core promoter element from a Zea mays Ubiquitin-1 gene promoter, and the full-length nucleotide sequence elements from a Rice Ubiquitin-3 promoter. Some embodiments relate to a synthetic bi-directional promoter that may function in plants to promote transcription of two operably linked nucleotide sequences.