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Poster: Biology & Disease Mgmt: Mycology


Genome and transcriptome analysis of Phellinus noxius, a wood decay fungus
H. LEE (1), C. Chen (2), I. Tsai (3), R. Liou (2), C. Chung (2) (1) National Taiwan University, Taiwan; (2) National Taiwan University, Taiwan; (3) Academia Sinica, Taiwan

Phellinus noxius, which causes brown root rot disease in more than 200 tree species, has recently gained much attention in East Asia. However, little is known about the genome of P. noxius. In this study, four mate-pair libraries of a P. noxius basidiospore isolate A42 were sequenced by using Illumina platform. Genome assembly and ab intio gene prediction resulted in a draft genome of ~32 Mb (N50 = 1.55 Mb) which includes 11,025 coding sequences. Both A and B mating type loci were identified. Sequence alignment of A42 and a Japanese isolate showed high similarity in B locus and one of the two HD1-HD2 pairs in A locus. Sequence analysis of the B locus of 12 basidiospore isolates from a single basidiocarp showed no polymorphism, which suggests a bipolar mating system. To facilitate gene annotation and to better understand the expression profiles of genes involved in stress responses, transcriptomes under various stress conditions were examined, encompassing temperature shift and nutrient deficiency (minimal medium, carbon deficiency, nitrogen deficiency). Genes involved in nutrient metabolism, secondary metabolites biosynthesis, hydrophobin production, and stress responses were induced. A particularly up-regulated pattern was found in the glyoxylate metabolism pathway which produces oxalate, an organic acid known to facilitate the activity of cell-wall degrading enzymes, as a byproduct. Investigations of the stress-related genes in disease development are underway.