Mstu1, an APSES Transcription Factor, Is Required for Appressorium-Mediated Infection in Magnaporthe grisea

• Published in: Bioscience, biotechnology, and biochemistry Vol. 73; no. 8; pp. 1779 - 1786
• Main Authors: NISHIMURA, Marie, FUKADA, Junji, MORIWAKI, Akihiro, FUJIKAWA, Takashi, OHASHI, Miho, HIBI, Tadaaki, HAYASHI, Nagao
• Format: Journal Article
• Language: English
• Published: Tokyo Japan Society for Bioscience, Biotechnology, and Agrochemistry 01.08.2009; Japan Society for Bioscience Biotechnology and Agrochemistry; Oxford University Press
• Subjects: Ascomycetes; Biological and medical sciences; Fertility; Fundamental and applied biological sciences. Psychology; Fungal Proteins - genetics; Fungal Proteins - metabolism; glycogen; Glycogen - metabolism; lipid; Lipid Metabolism; Magnaporthe - genetics; Magnaporthe - metabolism; Magnaporthe - physiology; Magnaporthe grisea; Movement; Mycelium - genetics; Mycelium - metabolism; Mycelium - physiology; Oryza - microbiology; Oryza sativa; pathogenicity; Plant Diseases - microbiology; Plant Leaves - microbiology; Reproduction, Asexual; Sequence Deletion; Spores, Fungal - physiology; StuA; Time Factors; Transcription Factors - genetics; Transcription Factors - metabolism; transfer; Ascomycota; Fungi; Infection; Pathogenicity; Magnaporthe grisea; Glycogen; Transfer; Lipids; StuA; Transcription factor; lipid
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1271/bbb.90146

The APSES protein family includes important transcriptional regulators of morphological processes in ascomycetes. We identified a deletion mutant of the APSES protein Mstu1 in Magnaporthe grisea that showed reduced conidiation and mycelial growth. Mstu1 formed a number of appressoria comparable to the wild type, although appressorium formation was delayed. In M. grisea, rapid transfer of conidial glycogen and lipid droplets to incipient appressoria is required for appressorial turgor generation, which the fungus uses to penetrate plant cuticles. Appressorial turgor was low in mstu1 and the mutant was deficient in appressorium-mediated invasion of rice leaves. The transfer of conidial glycogen and lipid droplets was remarkably delayed in mstu1, and a consequent delay in degradation of these conidial reserves was observed. Our results indicate that Mstu1 is required for appressorium-mediated infection due to its involvement in the mobilization of lipids and glycogen.