Mstu1, an APSES transcription factor, is required for appressorium-mediated infection in Magnaporthe grisea.
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.
Nishimura
Marie
M
National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan. marie@affrc.go.jp
Fukada
Junji
J
Moriwaki
Akihiro
A
Fujikawa
Takashi
T
Ohashi
Miho
M
Hibi
Tadaaki
T
Hayashi
Nagao
N
D005298:Fertility; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D006003:Glycogen / Q000378:metabolism; D050356:Lipid Metabolism; D020082:Magnaporthe / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D009068:Movement; D025282:Mycelium / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D012275:Oryza / Q000382:microbiology; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology; D012100:Reproduction, Asexual; D017384:Sequence Deletion; D013172:Spores, Fungal / Q000502:physiology; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D005656:Fungal Proteins; D014157:Transcription Factors; D006003:Glycogen