A Homeobox Gene Is Essential for Conidiogenesis of the Rice Blast Fungus Magnaporthe oryzae

• DOI: 10.1094/mpmi-23-4-0366
• Publication Date: 2010-03-01T21:14:44Z
• Authors: Wende Liu; Shiyong Xie; Xinhua Zhao; Xin Chen; Wenhui Zheng; Guodong Lu; Jin-Rong Xu; Zonghua Wang
• Keywords: Conidiation; Magnaporthe; Appressorium; Fungal protein

Magnaporthe oryzae starts its infection by the attachment of pyriform conidia on rice tissues, and severity disease epidemic is proportional to quantity produced in blast lesions. However, mechanism conidial production not well understood. Homeodomain proteins play critical roles regulating various growth developmental processes fungi other eukaryotes. Through targeted gene replacement, we find that deletion HTF1, one seven homeobox genes fungal genome, does affect mycelial but causes total defect production. Further observation revealed Deltahtf1 mutant produces significantly more conidiophores, which curve slightly near tip could develop sterigmata-like structures. Although fails form conidia, it still melanized appressoria from hyphal tips infect plants. The expression level HTF1 reduced Deltamgb1 G-beta DeltacpkA mutant, ACR1 CON7 encodes transcription factor required for normal conidiogenesis downregulated mutant. These data suggest essential conidiogenesis, may be functionally related trimeric G-protein signaling transcriptional regulators are known important conidiation M. oryzae.