The present invention provides an isolated promoter or an active fragment or derivative thereof capable of conferring selective expression on a gene to which it is operably connected in the endosperm of a developing plant seed and preferably in the basal endosperm transfer layer (BETL) of endosperm. The present invention also provides expression vectors and constructs and transgenic plant cells, plant parts and whole plants comprising the promoter, active fragments and derivatives, and well as methods of modulating one or more plant phenotypes employing the promoter, active fragments and derivatives.