Phytotoxic cyclic lipopeptides produced by Fusarium graminearum.
Proceedings of the 14th European Fusarium Seminar, Tulln, Austria, Apr 8-11, 2018, P. 27, Invited talk. https://www.efs14.at/program.php
Fusarium graminearum is a broad host pathogen causing FHB in diverse cereal crops. Investigating host-preferential gene expression, we identified a nonribosomal peptide synthetase in F. graminearum responsible for the biosynthesis of two novel cyclic lipopeptides, named gramillin A and B. A combination of LC-HRMS as well as 1D and 2D-NMR experiments on 15N-enriched compounds were performed to determine the structure of the gramillins. Gramillins are phytotoxins, causing cell death in select plants including maize and Arabidopsis, but not wheat. These labile compounds can linearize under particular conditions and consequently lose their bioactivity. F. graminearum mutants unable to produce gramillins are less able to colonize maize silks but just as virulent as wildtype F. graminearum on wheat spikes.