We used non-radioactive DDRT-PCR to screen molecular variants at expression level in P.graminea and P.teres, grown in vitro with glucose or plant cell walls as sugar supplies. A number of differential transcripts were identified between the two species, either constitutive species specific or induced by growth conditions. The different types of transcripts can be exploited to address several questions about the biology of these two pathogens. Two clones corresponding to transcripts specifically induced by cell walls in P.graminea or in P.teres and one constitutively expressed in P.graminea have been sequenced. Preliminary sequence analysis shows some homology with known genes in database.