Pleomorphism in Ceratocystis ulmi: refractile lipid bodies

Abstract

Evidence is presented that the refractile bodies present in yeasts and blastospores of proline-grown Ceratocystis ulmi, causative agent of Dutch elm disease, are lipid storage bodies rather than viable microendospores. Additionally, it is hypothesized that the lipid bodies of C. ulmi grown in susceptible elm trees are enriched in unsaturated fatty acids and that the aggressive vs. nonaggressive distinction in C. ulmi can be interpreted in terms of the percent unsaturated fatty acids in their lipids.