A method of modifying at least one carbohydrate in a tissue of a plant is described. The method is typically applied to a sugarcane plant of the genus Saccharum method and includes the steps of inserting into a plant cell a gene silencing cassette which includes nucleic acid operably linked to transcription elements such as a monocotyledonous promoter for transcribing the nucleic acid in a plant cell, wherein transcription of the nucleic acid decreases activity of UMP synthase. The method further includes the steps of regenerating a transgenic plant from the plant cell and producing the tissue with increased carbohydrate content. Vectors for use therefor, as well as a transformed plant cell and a transgenic plant or plant part containing or derived from a transformed plant cell are also described.