Chitinase gene expression during mycoparasitic interaction of Trichoderma harzianum with its host

Susanne Zeilinger, Christiane Galhaup, Kathrin Payer, Sheridan L. Woo, Robert L. Mach, Csaba Fekete, Matteo Lorito, Christian P. Kubicek

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179 Citations (Scopus)

Abstract

For monitoring chitinase expression during mycoparasitism of Trichoderma harzianum in situ, we constructed strains containing fusions of green fluorescent protein (GFP) to the 5'-regulatory sequences of the T. harzianum nag1 (N-acetyl-β-D-glucosaminidase-encoding) and ech42 (42-kDa endochitinase-encoding) genes. Confronting these strains with Rhizoctonia solani led to induction of gene expression before (ech42) or after (nag1) physical contact. A 12-kDa cut-off membrane separating the two fungi abolished ech42 expression, indicating that macromolecules are involved in its precontact activation. No ech42 expression was triggered by culture filtrates of R. solani or by placing T. harzianum onto plates previously colonized by R. solani. Instead, high expression occurred upon incubation of T. harzianum with the supernatant of R. solani cell walls digested with culture filtrates or purified endochitinase 42 (CHIT42, encoded by ech42) from T. harzianum. The chitinase inhibitor allosamidin blocked ech42 expression and reduced inhibition of R. solani growth during confrontation. The results indicate that ech42 is expressed before contact of T. harzianum with R. solani and its induction is triggered by soluble chitooligosaccharides produced by constitutive activity of CHIT42 and/or other chitinolytic enzymes.

Original languageEnglish
Pages (from-to)131-140
Number of pages10
JournalFungal Genetics and Biology
Volume26
Issue number2
DOIs
Publication statusPublished - Mar 1999

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Keywords

  • Biocontrol
  • Endochitinase 42
  • Gene expression
  • Green fluorescent protein
  • Mycoparasitism
  • N-acetyl-β-D-glucosaminidase I
  • Trichoderma harzianum

ASJC Scopus subject areas

  • Microbiology
  • Genetics

Cite this

Zeilinger, S., Galhaup, C., Payer, K., Woo, S. L., Mach, R. L., Fekete, C., Lorito, M., & Kubicek, C. P. (1999). Chitinase gene expression during mycoparasitic interaction of Trichoderma harzianum with its host. Fungal Genetics and Biology, 26(2), 131-140. https://doi.org/10.1006/fgbi.1998.1111