The present invention provides transgenic higher plants and transgenic plant cells thereof which have been transformed with a plant translationally controlled tumor protein (TCTP) gene to improve growth rate in a growth stage-dependent manner, especially in the earlier vegetative growth stage from seedlings to young plants. Also, the invention provides methods for engineering higher plants so that they can be more efficiently transformed with other transforming vector constructs. Further, provided are TCTP expression vectors which contain an uninterrupted coding region for the TCTP protein used to generate transgenic plants and cells thereof.