The present invention provides compositions and methods for regulating expression of heterologous nucleotide sequences in a plant. Compositions include a novel promoter nucleotide sequence for the gene encoding ubiquitin in Tripsacum dactyloides, as well as vectors, microorganisms, plants and plant cells having the promoter nucleotide sequence, or variants and fragments thereof. Methods for expressing a heterologous nucleotide sequence in a plant using the promoter sequences disclosed herein are also provided. The methods include stably incorporating into the genome of a plant cell a nucleotide sequence operably linked to the promoter of the present invention and regenerating a stably transformed plant that expresses the nucleotide sequence.