Isolation and characterisation of five different hydrophobin-encoding cDNAs from the fungal tomato pathogen Cladosporium fulvum

Abstract

Five different hydrophobin-encoding cDNA clones from Cladosporium fulvum were isolated from cDNA libraries, made from nutrient-depleted mycelium. One cDNA clone was identical to the previously isolated hydrophobin HCf-1. The other clones were named HCf-2, -3, -4 and -5. HCf-1, -2, -3 and -4 show a high degree of identity, and are predicted to encode class I hydrophobins. HCf-5 encodes a class II hydrophobin. The expression patterns of these hydrophobins at various stages of development, and in liquid media lacking either carbon or nitrogen, or both, showed clear differences. All hydrophobins were more strongly expressed during sporulation than before, with HCf-4 and -5 showing the highest increase. Expression of HCf genes in infected plants was also higher at 16 days than at 10 days after infection. The expression of HCf-5 in sporulating mycelium was much lower in planta than in vitro. All HCf genes were upregulated under conditions of nutrient deprivation. HCf-1, -2, -3 and -4 showed highest levels of transcription in medium lacking both carbon and nitrogen. Expression of HCf-5 was highest in medium lacking nitrogen but containing carbon. HCf-1 was generally the most abundant hydrophobin. The introduction of multiple copies of HCf-1, which caused co-suppression of the endogenous HCf-1 gene, was shown to affect the expression of HCf-2, -3 and -4 also. Expression of HCf-4 was suppressed, but expression of HCf-2 and -3 was upregulated. Expression of HCf-5 was not changed.

Targeted Gene Silencing in the Model Mushroom Coprinopsis cinerea ( Coprinus cinereus ) by Expression of Homologous Hairpin RNAs

“…However, this conclusion is hampered by the fact that experimental attempts to demonstrate the splicing of the loop intron failed (data not shown) and that all silencing constructs used in the present study contained additional introns as a prerequisite for their expression. The lack of silencing in some of the transformants despite the presence of a complete silencing cassette may be due to a lack of expres- The simultaneous silencing of cgl1 and cgl2 using the cgl2 hairpin construct is, apart from a report on Cladosporium fulvum (54), the only demonstration of this feature of RNAmediated gene silencing in a fungus. The effect is possibly restricted to highly homologous genes (the coding regions of cgl1 and cgl2 are 87% identical) since the less homologous cgl3 gene (53% overall identity to cgl2 in its coding region) is not affected.…”

“…In fungi, studies of transgeneinduced gene silencing (quelling) in N. crassa were instrumental for the discovery of the mechanism and the genetic dissection of the underlying machinery (see reference 10 for a review). In the meantime, homology-based gene silencing induced by transgenes (cosuppression), antisense, or dsRNA has been demonstrated for many fungi including zygo-, asco-, and basidiomycetes (15,19,20,22,23,29,37,43,44,46,50,54,58,64). For homobasidiomycetes, there is one report of transgeneinduced silencing in Schizophyllum commune (53).…”

The Role of the Extracellular Matrix (ECM) in Phytopathogenic Fungi: A Potential Target for Disease Control

“…Class I hydrophobins form highly insoluble polymers, whereas class II hydrophobins form polymers that are soluble in some organic solvents (Sunde et al, 2008). These hydrophobins are differentially expressed during the growth stage, and seem to have different functions (Nielsen et al, 2001;Segers et al, 1999;Wessels et al, 1991;Whiteford et al, 2004). In M. oryzae, two hydrophobins are well characterized: class I Mpg1 (Talbot et al, 1993) and class II Mhp1 (Kim et al, 2005).…”

The β-1,3-Exoglucanase GeneexgA(exg1) ofAspergillus oryzaeIs Required to Catabolize Extracellular Glucan, and Is Induced in Growth on a Solid Surface

“…22,23) Secretory production of hydrophobin and cutinase has been implicated in infection by plantpathogenic fungi. [22][23][24][25] The hydrophobin ortholog RolA and the cutinase ortholog CutL1 have been reported in A. oryzae, and were found to function in plant surface interaction. 26,27) The expression of the rolA and cutL1 genes in A. oryzae was analyzed in culture on the filter membrane and onion inner skin.…”