The present disclosure concerns methods and compositions relating to UXS polypeptides and/or nucleic acids encoding UXS polypeptides. In certain claims, the methods and compositions are of use to improve digestibility and/or ease of grain processing. Such improvements relate to a modulation in arabinoxylan and/or hemicellulose content in transgenic plants. Such plants can, for example, comprise one or more nucleic acid sequences that inhibit expression of one or more UDP-Xylose Synthase (UXS) genes.