HFB7 – A novel orphan hydrophobin of the Harzianum and Virens clades of Trichoderma, is involved in response to biotic and abiotic stresses

摘要: Hydrophobins are small secreted cysteine-rich proteins exclusively found in fungi. They able to self-assemble single molecular layers at hydrophobic-hydrophilic interfaces and can therefore be directly involved establishment of fungi their habitat. The genomes filamentous mycotrophic Trichoderma encode a rich diversity hydrophobins, which divided several groups based on structure evolution. Here we describe new member class II HFB7, that has taxonomically restricted occurrence Harzianum Virens clades Trichoderma. Evolutionary analysis reveals HFB7 form separate clade distinct from other hydrophobins genes encoding them evolve under positive selection pressure. Homology modelling comparison T. reesei HFB2 the two large hydrophobic patches surface protein remarkably conserved between despite significant difference primary structures. Expression hfb7 gene virens increases interactions with plant response abiotic stress conditions, is also upregulated during formation aerial mycelium standing liquid culture. This upregulation significantly exceeds expression strong constitutive promoter, strains overexpressing thus display only changes traits characterized by low expression, i.e. faster growth submerged not expressed conidia. Our data allow conclude this defence against factors related oxidative stress. Moreover, likely helps fungus wetlands or conditions high humidity.