The present invention provides compositions and methods for manipulation of plant polysaccharides and plant polysaccharide synthases. Compositions include novel nucleotide sequences encoding polysaccharide synthases polypeptides, and biologically active variants thereof. Further provided are methods for polysaccharide manipulation using the sequences disclosed herein. One method comprises stably incorporating into the genome of a plant cell, a nucleotide sequence of the present invention operably linked to a heterologous promoter and regenerating a stably transformed plant that expresses the nucleotide sequence. Methods for enhancing digestibility of plants, improving gum extractability from plants, and altering plant growth are also provided.