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Applied Microbiology and Biotechnology

, Volume 54, Issue 3, pp 370–375 | Cite as

Regulation of xyn3 gene expression in Trichoderma reesei PC-3–7

  • J. Xu
  • M. Nogawa
  • H. Okada
  • Y. Morikawa
ORIGINAL PAPER

Abstract

The characteristics of regulation of the gene encoding the third xylanase (Xyn III) of a filamentous fungus, Trichoderma reesei PC-3–7, were studied by Northern blot analysis. A partial DNA sequence (185 bp) of the xyn3 gene was obtained by PCR amplification of genomic DNA of T. reesei PC-3–7 and sequenced. This xyn3 gene fragment was used as a probe for Southern and Northern blot analysis. The expression of the xyn3 gene was regulated at the transcriptional level. The xyn3 mRNA was expressed in mycelia of T. reesei PC-3–7 induced by Avicel, l-sorbose and sophorose, but not by xylose, xylooligosaccharides and birchwood xylan. Furthermore, it was observed that xyn3 was synchronously expressed with egl1 but not with xyn1 and xyn2 by l-sorbose, indicating that the xyn3 gene may be coordinately expressed with cellulase genes. By Southern blot analysis, the xyn3 gene was confirmed to exist as a single copy in both strains of T. reesei PC-3–7 and QM9414. However, no xyn3 mRNA appeared in the mycelia induced by any kind of inducers in T. reesei QM9414 even when total RNA was used in large excess, suggesting that the xyn3 gene in T. reesei QM9414 is in the dormant state and cannot be expressed. Therefore, T. reesei PC-3–7 may be a very useful strain for elucidating the induction mechanism of xylanase biosynthesis by cellulosic and xylanosic substrates, and also the regulatory correlation between cellulase and xylanase induction.

Keywords

Xylose Cellulase Southern Blot Trichoderma Filamentous Fungus 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • J. Xu
    • 1
  • M. Nogawa
    • 1
  • H. Okada
    • 1
  • Y. Morikawa
    • 1
  1. 1.Department of Bioengineering, Nagaoka University of Technology, Kamitomioka 1603-1, Nagaoka, Niigata 940-2188, Japan Tel.: +81-258-479407 Fax: +81-258-479407JP

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