Occurrence of N-acetylhexosaminidase-encoding genes in ectomycorrhizal basidiomycetes

Authors

  • Björn D. Lindahl,

    Corresponding author
    1. Department of Forest Mycology and Pathology, SLU, Box 7026, SE-750 07 Uppsala, Sweden
      Author for correspondence: Björn Lindahl Tel: +46 18 672725 Fax: +46 18 673599 Email: bjorn.lindahl@mykopat.slu.se
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  • Andy F. S. Taylor

    1. Department of Forest Mycology and Pathology, SLU, Box 7026, SE-750 07 Uppsala, Sweden
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Author for correspondence: Björn Lindahl Tel: +46 18 672725 Fax: +46 18 673599 Email: bjorn.lindahl@mykopat.slu.se

Summary

  • • The genetic potential of ectomycorrhizal fungi to produce N-acetylhexosaminidases was investigated here. N-acetylhexosaminidases are enzymes that cleave monosaccharides from oligomers of N-acetylhexosamines and play an important role in the degradation of chitin.
  • • Degenerate PCR-primers were designed against genes coding for N-acetylhexosaminidases in basidiomycetes. PCR was performed with DNA templates extracted from sporocarps of 26 ectomycorrhizal fungal species and two saprotrophs.
  • • PCR-products were obtained from 18 species representing 12 genera distributed throughout the basidiomycete phylogeny. Sequencing confirmed that the products were homologous with N-acetylhexosaminidase genes from plants, animals and other fungi. Some species yielded two PCR-products representing isoenzymes.
  • • Chitin constitutes a potentially important nitrogen source in soil. Our results demonstrate that a wide range of ectomycorrhizal fungi have the genetic potential to produce N-acetylhexosaminidases, and the expression of this potential would enable them to exploit polymers of amino sugars as a source of nitrogen for themselves and their host plants.

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