Gene identification in the obligate fungal pathogen Blumeria graminis by expressed sequence tag analysis

Powdery mildew of barley is caused by the obligate fungal pathogen Blumeria graminis f. sp. hordei. Haploid conidia of B. graminis, landing on the bar ley leaf, germinate to form first a primary germ tube and then an appressor ial germ tube. The appressorial germ tube differentiates into a mature appr essorium from which direct penetration of host epidermis occurs. Here we pr esent data on 4908 expressed sequence tags obtained from B. graminis conidi a. The combined sequences represent 2676 clones describing 1669 individual genes. Comparison with sequences from other pathogenic and nonpathogenic fu ngi defines hypotheses on the genes required for pathogenicity and growth o n the host. The putative roles of some of the identified genes are discusse d. (C) 2001 Academic Press.