Abstract: This invention relates generally to plant cells and/or plants with increased yield as compared to a corresponding non-transformed wild type plant cell by increasing or generating one or more activities of polypeptides associated with the intermediate phosphoribosylpyrophosphate (PRPP) in plants. In particular, this invention relates to plant cells and/or plants with increased yield as compared to a corresponding non-transformed wild type plant cell by increasing or generating one or more activities of phosphoribosyl pyrophosphate synthases (PRPP synthetase, PRS) The invention also deals with methods of producing and screening for and breeding such plant cells and/or plants.