The invention relates to methods for increasing the oil content in plants, preferably in plant seeds, by expressing the Ypr140w polypeptide from yeast or corresponding polypeptides from plants. The invention furthermore relates to expression constructs for expressing the yeast polypeptide Ypr140w or corresponding polypeptides from plants in plants, preferably in plant seeds, the transgenic plants expressing the polypeptide and to the use of the transgenic plants for the production of food, feed, seed, pharmaceuticals or fine chemicals, in particular for the production of oils.