The invention provides compositions and methods for inhibiting the expression of the gene XAX1 in grass plants. Plants with inhibited expression of XAX1 have use, e.g., in biofuel production by increasing the amount of soluble sugar that can be extracted from the plant.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
 This invention was made with government support under DE-AC02-05CH11231 awarded by the United States Department of Energy. The government has certain rights in the invention.