Analysis of Expressed Sequence Tags from the Fungal Banana Pathogen Mycosphaerella fijiensis

ABSTRACT

Mycosphaerella fijiensis is a fungal pathogen causing black leaf streak disease in banana plants. In order to develop our understanding of the molecular mechanisms of host infection by M. fijiensis, we initiated a first step towards large-scale gene discovery through the generation and analysis of expressed sequence tags (ESTs). Three cDNA libraries representing different culture conditions were constructed. A subset of clones was sequenced at the 5’ end and a total of 3,771 ESTs were generated. These ESTs were clustered into a set of 1,945 unique sequences. BLASTX analysis indicated that 410 of the unisequences showed homology to genes with known function, including those related to pathogenicity and virulence. Meanwhile, 66% and 89% of the ESTs matched to the predicted transcripts and genome sequences of M. fijiensis, respectively. The diversity of the EST collection developed in this study will facilitate genome annotation as well as identification and characterization of genes involved in host infection and fungal development through a comparative and functional genomics approach.