A PROMOTER DIRECTING EPIDERMAL EXPRESSION IN TRANSGENIC ALFALFA

We describe the isolation, cloning and expression of a 2.8 kb promoter fragment of the Blec4 gene from pea (Pisum sativum cv. Alaska) and de monstrate that it is capable of directing the expression of the beta-g lucuronidase coding region to the developing epidermal tissue of veget ative and floral shoot apices of transgenic alfalfa (Medicago sativa c v. RegenSY). The Blec4 promoter represents a useful tool with which to target the expression of foreign genes to the epidermal layer of acti vely growing shoots. The activity of the Blec4 promoter in the epiderm is of the shoot apex makes it particularly suitable for genetically en gineering defense against insects and diseases that attack the growing shoot apex.