Cloning and targeted gene disruption of EXG1, encoding Exo-(beta)1,3-glucanase, in the phytopathogenic fungus Cochliobolus carbonum

The phytopathogenic fungus Cochliobolus carbonum produces an extracellular enzyme capable of degrading beta1,3-glucan in an exolytic manner. On the basis of partial amino acid sequences of the purified enzyme, two degenerate oligonucleotides were synthesized and used as PCR primers to amplify a 1.1-kb fragment of corresponding genomic DNA, called EXG1.