Identification of Fcl-29 as an Effective Antifungal Natural Product against Fusarium graminearum and Combinatorial Engineering Strategy for Improving Its Yield.

Fusarium head blight (FHB), caused by Fusarium graminearum , whose occurrence and prevalence causes 10-70% wheat production loss, is one of the most destructive diseases influencing the production of wheat globally. To identify the potential natural products (NPs) against F. graminearum , we screened 59 Xenorhabdus strains and discovered that the cell-free supernatant (CFS) of X. budapestensis 14 (XBD14) displays the highest bioactivity. Multiple genetic methods coupled with HRMS/MS analysis determined the major antifungal NP to be Fcl-29, a fabclavine derivative. Fcl-29 was found to effectively control FHB of wheat in the field test and demonstrated broad-spectrum antifungal activity against important pathogenic fungi. The production of Fcl-29 was dramatically improved by 33.82-fold with the combinatorial strategy of genetic engineering (1.66-fold) and fermentation engineering (20.39-fold). The exploration of a new biofungicide in global plant protection is now possible.