Eucalyptus species are the most widely planted hardwood species in the world and are renowned for their rapid growth and adaptability. In Brazil, one of the most widely grown Eucalyptus cultivars is the fast-growing Eucalyptus urophylla x Eucalyptus grandis hybrid. | Flavonoid supplementation affects the expression of genes involved in cell wall formation and lignification metabolism and increases sugar content and saccharification in the fast-growing eucalyptus hybrid E. urophylla x E. grandis