Expression of a modified Avr3a gene under the control of a synthetic pathogen-inducible promoter leads to Phytophthora infestans resistance in potato.

Late blight resistance of potato was improved by the co-expression of the potato resistance gene R3a and the pathogen-inducible avirulence gene Avr3a of Phytopthora infestans. The synthetic pathogen-inducible promoter 2xS-4xD-NpCABE, which is composed of the cis-acting elements S and D and the core promoter of the NpCABE gene, was developed for potato. By analysis of 20 core promoters from Solanacea species synthetic promoters of the 2xS-2xD-type were generated which differ in their background activity, strength and promoter inducibility.