Functional analysis of hydrophobin genes in sexual development of Botrytis cinerea

R.B. Terhem, J.A.L. van Kan

Research output: Contribution to journalArticleAcademicpeer-review

9 Citations (Scopus)

Abstract

Hydrophobins are small secreted fungal proteins that play roles in growth and development of filamentous fungi, i.e. in the formation of aerial structures and the attachment of hyphae to hydrophobic surfaces. In Botrytis cinerea, three hydrophobin genes have been identified. Studies by Mosbach et al. (2011) showed that hydrophobins are neither involved in conferring surface hydrophobicity to conidia and aerial hyphae of B. cinerea, nor are they required for virulence. The present study investigated the role of hydrophobins in sclerotium and apothecium development. Expression analysis revealed high expression of the Bhp1 gene during different stages of apothecium development. Two Bhp1 splice variants were detected that differ by an internal stretch of 13 amino acid residues. Seven different mutants in which either a single, two or three hydrophobin genes were knocked out, as well as two wild type strains of opposite mating types, were characterized for sclerotium and apothecium development. No aberrant morphology was observed in sclerotium development when single deletion mutants in hydrophobin genes were analyzed. Sclerotia of double knock out mutant ¿Bhp1/¿Bhp3 and the triple knock out mutant, however, showed easily wettable phenotypes. For analyzing apothecium development, a reciprocal crossing scheme was setup. Morphological aberrations were observed in crosses with two hydrophobin mutants. When the double knock out mutant ¿Bhp1/¿Bhp2 and the triple knock out mutant were used as the maternal parent (sclerotia), and fertilized with wild type microconidia, the resulting apothecia were swollen, dark brown in color and had a blotched surface. After initially growing upwards toward the light source, the apothecia in many cases collapsed due to loss of structural integrity. Aberrant apothecium development was not observed in the reciprocal cross, when these same mutants were used as the paternal parent (microconidia). These results indicate that the presence of hydrophobins in maternal tissue is important for normal development of apothecia of B. cinerea.
Original languageEnglish
Pages (from-to)42-51
JournalFungal Genetics and Biology
Volume71
DOIs
Publication statusPublished - 2014

Fingerprint

Botrytis
Sexual Development
Hyphae
Mothers
Genes
Fungal Proteins
Fungal Spores
Hydrophobic and Hydrophilic Interactions
Growth and Development
Virulence
Fungi
Color
Phenotype
Gene Expression
Light
Amino Acids

Keywords

  • neurospora-crassa conidia
  • chestnut blight fungus
  • rodlet layer
  • cryphonectria-parasitica
  • schizophyllum-commune
  • aerial hyphae
  • cell-surface
  • expression
  • proteins
  • sc3

Cite this

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title = "Functional analysis of hydrophobin genes in sexual development of Botrytis cinerea",
abstract = "Hydrophobins are small secreted fungal proteins that play roles in growth and development of filamentous fungi, i.e. in the formation of aerial structures and the attachment of hyphae to hydrophobic surfaces. In Botrytis cinerea, three hydrophobin genes have been identified. Studies by Mosbach et al. (2011) showed that hydrophobins are neither involved in conferring surface hydrophobicity to conidia and aerial hyphae of B. cinerea, nor are they required for virulence. The present study investigated the role of hydrophobins in sclerotium and apothecium development. Expression analysis revealed high expression of the Bhp1 gene during different stages of apothecium development. Two Bhp1 splice variants were detected that differ by an internal stretch of 13 amino acid residues. Seven different mutants in which either a single, two or three hydrophobin genes were knocked out, as well as two wild type strains of opposite mating types, were characterized for sclerotium and apothecium development. No aberrant morphology was observed in sclerotium development when single deletion mutants in hydrophobin genes were analyzed. Sclerotia of double knock out mutant ¿Bhp1/¿Bhp3 and the triple knock out mutant, however, showed easily wettable phenotypes. For analyzing apothecium development, a reciprocal crossing scheme was setup. Morphological aberrations were observed in crosses with two hydrophobin mutants. When the double knock out mutant ¿Bhp1/¿Bhp2 and the triple knock out mutant were used as the maternal parent (sclerotia), and fertilized with wild type microconidia, the resulting apothecia were swollen, dark brown in color and had a blotched surface. After initially growing upwards toward the light source, the apothecia in many cases collapsed due to loss of structural integrity. Aberrant apothecium development was not observed in the reciprocal cross, when these same mutants were used as the paternal parent (microconidia). These results indicate that the presence of hydrophobins in maternal tissue is important for normal development of apothecia of B. cinerea.",
keywords = "neurospora-crassa conidia, chestnut blight fungus, rodlet layer, cryphonectria-parasitica, schizophyllum-commune, aerial hyphae, cell-surface, expression, proteins, sc3",
author = "R.B. Terhem and {van Kan}, J.A.L.",
year = "2014",
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language = "English",
volume = "71",
pages = "42--51",
journal = "Fungal Genetics and Biology",
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}

Functional analysis of hydrophobin genes in sexual development of Botrytis cinerea. / Terhem, R.B.; van Kan, J.A.L.

In: Fungal Genetics and Biology, Vol. 71, 2014, p. 42-51.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Functional analysis of hydrophobin genes in sexual development of Botrytis cinerea

AU - Terhem, R.B.

AU - van Kan, J.A.L.

PY - 2014

Y1 - 2014

N2 - Hydrophobins are small secreted fungal proteins that play roles in growth and development of filamentous fungi, i.e. in the formation of aerial structures and the attachment of hyphae to hydrophobic surfaces. In Botrytis cinerea, three hydrophobin genes have been identified. Studies by Mosbach et al. (2011) showed that hydrophobins are neither involved in conferring surface hydrophobicity to conidia and aerial hyphae of B. cinerea, nor are they required for virulence. The present study investigated the role of hydrophobins in sclerotium and apothecium development. Expression analysis revealed high expression of the Bhp1 gene during different stages of apothecium development. Two Bhp1 splice variants were detected that differ by an internal stretch of 13 amino acid residues. Seven different mutants in which either a single, two or three hydrophobin genes were knocked out, as well as two wild type strains of opposite mating types, were characterized for sclerotium and apothecium development. No aberrant morphology was observed in sclerotium development when single deletion mutants in hydrophobin genes were analyzed. Sclerotia of double knock out mutant ¿Bhp1/¿Bhp3 and the triple knock out mutant, however, showed easily wettable phenotypes. For analyzing apothecium development, a reciprocal crossing scheme was setup. Morphological aberrations were observed in crosses with two hydrophobin mutants. When the double knock out mutant ¿Bhp1/¿Bhp2 and the triple knock out mutant were used as the maternal parent (sclerotia), and fertilized with wild type microconidia, the resulting apothecia were swollen, dark brown in color and had a blotched surface. After initially growing upwards toward the light source, the apothecia in many cases collapsed due to loss of structural integrity. Aberrant apothecium development was not observed in the reciprocal cross, when these same mutants were used as the paternal parent (microconidia). These results indicate that the presence of hydrophobins in maternal tissue is important for normal development of apothecia of B. cinerea.

AB - Hydrophobins are small secreted fungal proteins that play roles in growth and development of filamentous fungi, i.e. in the formation of aerial structures and the attachment of hyphae to hydrophobic surfaces. In Botrytis cinerea, three hydrophobin genes have been identified. Studies by Mosbach et al. (2011) showed that hydrophobins are neither involved in conferring surface hydrophobicity to conidia and aerial hyphae of B. cinerea, nor are they required for virulence. The present study investigated the role of hydrophobins in sclerotium and apothecium development. Expression analysis revealed high expression of the Bhp1 gene during different stages of apothecium development. Two Bhp1 splice variants were detected that differ by an internal stretch of 13 amino acid residues. Seven different mutants in which either a single, two or three hydrophobin genes were knocked out, as well as two wild type strains of opposite mating types, were characterized for sclerotium and apothecium development. No aberrant morphology was observed in sclerotium development when single deletion mutants in hydrophobin genes were analyzed. Sclerotia of double knock out mutant ¿Bhp1/¿Bhp3 and the triple knock out mutant, however, showed easily wettable phenotypes. For analyzing apothecium development, a reciprocal crossing scheme was setup. Morphological aberrations were observed in crosses with two hydrophobin mutants. When the double knock out mutant ¿Bhp1/¿Bhp2 and the triple knock out mutant were used as the maternal parent (sclerotia), and fertilized with wild type microconidia, the resulting apothecia were swollen, dark brown in color and had a blotched surface. After initially growing upwards toward the light source, the apothecia in many cases collapsed due to loss of structural integrity. Aberrant apothecium development was not observed in the reciprocal cross, when these same mutants were used as the paternal parent (microconidia). These results indicate that the presence of hydrophobins in maternal tissue is important for normal development of apothecia of B. cinerea.

KW - neurospora-crassa conidia

KW - chestnut blight fungus

KW - rodlet layer

KW - cryphonectria-parasitica

KW - schizophyllum-commune

KW - aerial hyphae

KW - cell-surface

KW - expression

KW - proteins

KW - sc3

U2 - 10.1016/j.fgb.2014.08.002

DO - 10.1016/j.fgb.2014.08.002

M3 - Article

VL - 71

SP - 42

EP - 51

JO - Fungal Genetics and Biology

JF - Fungal Genetics and Biology

SN - 1087-1845

ER -