COTRANSFORMATION OF METARHIZIUM-ANISOPLIAE BY ELECTROPORATION OR USING THE GENE GUN TO PRODUCE STABLE GUS TRANSFORMANTS

The potential of beta-glucuronidase as a molecular marker for studying the environmental microbiology of entomopathogenic fungi was assessed . Metarhizium anisopliae was stably co-transformed with plasmids (pNOM 102 and pBENA3) containing the beta-glucuronidase and benomyl resistan ce (beta-tubulin) genes, using both electroporation and biolistic deli very systems, and it was confirmed that the expressed phenotypes were not exhibited by ten randomly chosen indigenous North-American isolate s. In spite of random and multiple integrations, the co-transformants showed normal growth rates and retained their pathogenicity to insects . beta-Glucuronidase activity in the co-transformants was used to dete ct histochemically the presence of fungal hyphae in infected host inse cts (Bombyx mori) and thus provides a practical means of marking genet ically engineered pathogens for field trials.