positive regulation negative regulation stage of development signal

positive regulation negative regulation stage of development signal receptor + adenyl cyclase MAPK transcription factor X heterotrimeric G protein dissociation protein kinase Talbot Ann Rev of Microbiol 2003

spore tip mucilage Howard and Valent Annu. Rev. Microbiol. 1996

chitin WT albino melanin appressorium pore Howard and Valent 1996

melanin biosynthesis Howard and Valent 1996

Collapse high concentration of non-permeable solute conidium germ tube appressorium sonicated cells Howard and Valent 1996

Cosegregation of the appressorium deficiency phenotype with the mpg 1: : Hph deletion allele. WT mpg 1 - hyg. S hyg. R hyg. S MPG 1 directs formation of the hydrophobic rodlet layer of conidia. WT mpg 1 - hyg. R WT mpg 1 MPG 1+ Reintroduction of MPG 1 restores pathogenicity, appressorium development and cell surface hydrophobicity mpg 1 -; hyg. R MPG 1 -; hyg. S Talbot et al 1996

appressoria build turgor during incubation 1 -6 > hardness water incubation softer = earlier penetration PEG > conc >hardness = lower pressure to inhibit penetration Howard et al 1991

homeodomain WT Zn finger mutants Park et al 2004

WT mst 1 - appressoria can form can’t penetrate no peg From Park et al 2004 MST 1 is dispensable for mobilization of glycogen and lipid storage molecules A. Glycogen stained with iodine moved from conidia to appressoria and degraded B. Lipid droplets stained with Nile Red Upper =DIC Lower = epifluorescence Park et al 2004