The cyclic tetrapeptide HC-toxin is required for pathogenicity of the filamentous fungus Cochliobolus carbonum on maize. HC-toxin production is controlled by a complex locus, TOX2. The isolation and characterization of a new gene of the TOX2 locus, TOXF, is reported. It is shown that TOXF is specifically required for HC-toxin production and pathogenicity. It is present as two or three copies in...

Common root rot caused by Cochliobolus sativus is a serious disease of barley. A simple and reliable method for assessing this disease would enhance our capacity in identifying resistance sources and developing resistant barley cultivars. In searching for such a method, a conidial suspension of C. sativus was dropped onto sterilized elongated subcrown internodes and incubated in sandwich filter...