Genetic Conversion of a Fungal Plant Pathogen to a Nonpathogenic, Endophytic Mutualist

See allHide authors and affiliations

Science  02 Apr 1993:
Vol. 260, Issue 5104, pp. 75-78
DOI: 10.1126/science.260.5104.75


The filamentous fungal ascomycete Colletotrichum magna causes anthracnose in cucurbit plants. Isolation of a nonpathogenic mutant of this species (path-1) resulted in maintained wild-type levels of in vitro sporulation, spore adhesion, appressorial formation, and infection. Path-1 grew throughout host tissues as an endophyte and retained the wild-type host range, which indicates that the genetics involved in pathogenicity and host specificity are distinct. Prior infection with path-1 protected plants from disease caused by Colletotrichum and Fusarium.Genetic analysis of a cross between path-1 and wild-type strains indicated mutation of a single locus.