Identification of an in planta-induced mRNA of Plasmodiophora brassicae

RNA fingerprinting using the arbitrarily primed polymerase chain reaction ( RAP) were performed with a host-pathogen system consisting of a Chinese cab bage cultivar and two isolates of Plasmodiophora brassicae. One of the RAP products expressed specifically in a susceptible response (clubroots) was i solated, cloned, and sequenced. Northern blot analysis confirmed that the p roduct (Y10) was expressed in clubroot tissue where P, brassicae was shown to be at a vegetative growth stage. Southern blot analysis suggested that t he Y10 sequence existed as a single-copy per haploid genome of P. brassicae . Thus, Y10 sequence appears to be a transcript from P, brassicae growing i n planta.