Identification of an elicitin gene cluster in Phytophthora cinnamomi

Elicitins are a group of highly conserved proteins secreted by species of P hytophthora and a species of the related genus Pythium, Pythium vexans. Som e of these proteins act as inducers of the necrotic hypersensitive-like res ponse and the associated systemic acquired resistance phenomenon, in some s pecies. We cloned and characterised the cinnamomin-beta and -alpha genes an d two related elicitin genes from Phytophthora cinnamomi. These four open r eading frames (ORFs) are clustered in tandem pairs. Two out of these four g enes present homologies with the basic and acidic elicitin groups; but the two others encode, if expressed, elicitin isoforms exhibiting homologies wi th the class II of highly acidic elicitins.