The invention relates to transgenic expression constructs and vectors comprising plant promoters with a non-seed tissue, preferably vegetative plant tissue specific expression profile, and the use of these transgenic expression constructs or vectors for the transgenic expression of nucleic acid sequences in plants. More preferably, the promoters of the invention are the promoter of the Pisum sativum ptxA gene, or the promoter of the Glycine max extensin (SbHRGP3) gene, and functional equivalent fragments and functional equivalent homologs thereof, or their complements, having essentially the same promoter activity. The invention furthermore relates to transgenic plants and plant cells transformed with these expression constructs or vectors, to cultures, parts or propagation material derived therefrom, and to the use of same for the preparation of foodstuffs, animal feeds, seed, pharmaceuticals or fine chemicals, to improve plant biomass, yield, or provide desirable phenotypes.