RT Journal Article SR Electronic T1 MPG1 Encodes a Fungal Hydrophobin Involved in Surface Interactions during Infection-Related Development of Magnaporthe grisea. JF The Plant Cell JO Plant Cell FD American Society of Plant Biologists SP 985 OP 999 DO 10.1105/tpc.8.6.985 VO 8 IS 6 A1 Talbot, N. J. A1 Kershaw, M. J. A1 Wakley, G. E. A1 De Vries, OMH. A1 Wessels, JGH. A1 Hamer, J. E. YR 1996 UL http://www.plantcell.org/content/8/6/985.abstract AB The rice blast fungus expresses a pathogenicity gene, MPG1, during appressorium formation, disease symptom development, and conidiation. The MPG1 gene sequence predicts a small protein belonging to a family of fungal proteins designated hydrophobins. Using random ascospore analysis and genetic complementation, we showed that MPG1 is necessary for infection-related development of Magnaporthe grisea on rice leaves and for full pathogenicity toward susceptible rice cultivars. The protein product of MPG1 appears to interact with hydrophobic surfaces, where it may act as a developmental sensor for appressorium formation. Ultrastructural studies revealed that MPG1 directs formation of a rodlet layer on conidia composed of interwoven ~5-nm rodlets, which contributes to their surface hydrophobicity. Using combined genetic and biochemical approaches, we identified a 15-kD secreted protein with characteristics that establish it as a class I hydrophobin. The protein is able to form detergent-insoluble high molecular mass complexes, is soluble in trifluoroacetic acid, and exhibits mobility shifts after treatment with performic acid. The production of this protein is directed by MPG1.