Large-Scale Gene Disruption in Magnaporthe oryzae Identifies MC69, a Secreted Protein Required for Infection by Monocot and Dicot Fungal Pathogens

• DOI: 10.1371/journal.ppat.1002711
• Publication Date: 2012-05-10T21:11:07Z
• Authors: Hiromasa Saitoh; Shizuko Fujisawa; Chikako Mitsuoka; Akiko Ito; Akiko Hirabuchi; Kyoko Ikeda; Hiroki Irieda; Kae Yoshino; Kentaro Yoshida; Hideo Matsumura; Yukio Tosa; Joe Win; Sophien Kamoun; Yoshitaka Takano; Ryohei Terauchi
• Keywords: Conidiation; Appressorium; Magnaporthe

To search for virulence effector genes of the rice blast fungus, Magnaporthe oryzae, we carried out a large-scale targeted disruption 78 putative secreted proteins that are expressed during early stages infection M. oryzae. Disruption majority did not affect growth, conidiation, or pathogenicity One exception was gene MC69. The mc69 mutant showed severe reduction in symptoms on and barley, indicating importance MC69 exhibit changes saprophytic growth conidiation. Microscopic analysis behavior revealed is dispensable appressorium formation. However, failed to develop invasive hyphae after formation leaf sheath, critical role interaction with host plants. encodes hypothetical 54 amino acids protein signal peptide. Live-cell imaging suggested fluorescently labeled translocated into cytoplasm. Site-directed mutagenesis two conserved cysteine residues (Cys36 Cys46) mature impaired function without affecting its secretion, suggesting disulfide bond function. Furthermore, deletion orthologous reduced cucumber anthracnose fungus Colletotrichum orbiculare both Nicotiana benthamiana leaves. We conclude commonly required different plant pathogenic fungi, oryzae C. monocot dicot plants, respectively.