The development of a heterologous transformation system for the cellulolytic fungus Trichoderma reesei based on a pyrG-negative mutant strain

Curr Genet. 1990 Jul;18(1):71-6. doi: 10.1007/BF00321118.


Six uridine auxotroph mutants of Trichoderma reesei QM 9414 were isolated by resistance to 5-fluoroorotic acid and one strain was identified as OMP-decarboxylase negative (pyr-) by a radiometric enzyme assay. Transformation to uridine prototrophy was achieved with the pyr4 gene of Neurospora crassa (up to 1500 transformants/micrograms) and with pyrA of Aspergillus niger (700-800 transformants/micrograms). In many transformants the PYR+ function seems to be present as extrachromosomal DNA. There is evidence for a correlation between the stability of transformants and integration of the vector in the genome whereas unstable transformants are obtained when autonomous replication of the plasmid occurs.

MeSH terms

  • Blotting, Southern
  • Chromatography, Thin Layer
  • Drug Resistance, Microbial / genetics
  • Genes, Fungal
  • Mutation*
  • Orotic Acid / analogs & derivatives
  • Orotic Acid / pharmacology
  • Orotidine-5'-Phosphate Decarboxylase / deficiency*
  • Orotidine-5'-Phosphate Decarboxylase / genetics
  • Transformation, Genetic*
  • Trichoderma / genetics*
  • Trichoderma / isolation & purification
  • Uridine / metabolism


  • Orotic Acid
  • 5-fluoroorotic acid
  • Orotidine-5'-Phosphate Decarboxylase
  • Uridine