Kazmierczak Pam, Kim Dae Hyuk, Turina Massimo, Van Alfen Neal K
Department of Plant Pathology, University of California-Davis, One Shields Ave., Davis, CA 95616, USA.
Eukaryot Cell. 2005 May;4(5):931-6. doi: 10.1128/EC.4.5.931-936.2005.
Hydrophobins are abundant small hydrophobic proteins that are present on the surfaces of many filamentous fungi. The chestnut blight pathogen Cryphonectria parasitica was shown to produce a class II hydrophobin, cryparin. Cryparin is the most abundant protein produced by this fungus when grown in liquid culture. When the fungus is growing on chestnut trees, cryparin is found only in the fungal fruiting body walls. Deletion of the gene encoding cryparin resulted in a culture phenotype typical of hydrophobin deletion mutants of other fungi, i.e., easily wettable (nonhydrophobic) hyphae. When grown on the natural substrate of the fungus, however, cryparin-null mutation strains were unable to normally produce its fungal fruiting bodies. Although the stromal pustules showed normal development initially, they were unable to erupt through the bark of the tree. The hydrophobin cryparin thus plays an essential role in the fitness of this important plant pathogen by facilitating the eruption of the fungal fruiting bodies through the bark of its host tree.
疏水蛋白是一类丰富的小疏水蛋白，存在于许多丝状真菌的表面。栗疫病菌Cryphonectria parasitica被证明能产生一种II类疏水蛋白——栗疫菌素。栗疫菌素是这种真菌在液体培养时产生的最丰富的蛋白质。当真菌在栗树上生长时，栗疫菌素仅存在于真菌子实体壁中。编码栗疫菌素的基因缺失导致了一种典型的其他真菌疏水蛋白缺失突变体的培养表型，即菌丝易于被湿润（非疏水）。然而，当在真菌的天然底物上生长时，栗疫菌素缺失突变菌株无法正常产生其子实体。尽管基质脓疱最初显示出正常发育，但它们无法穿透树皮喷发出来。因此，疏水蛋白栗疫菌素通过促进真菌子实体穿透寄主树的树皮，在这种重要植物病原菌的适应性方面发挥着重要作用。
