Major Facilitator Superfamily Transporter Gene Is Essential for to Deal with Salicylic Acid Stress and for Its Pathogenicity towards Wheat.

Wheat is a major staple food crop worldwide, due to its total yield and unique processing quality. Its grain yield and quality are threatened by Fusarium head blight (FHB), which is mainly caused by . Salicylic acid (SA) has a strong and toxic effect on and is a hopeful target for sustainable control of FHB. is capable of efficientdealing with SA stress. However, the underlying mechanisms remain unclear. Here, we characterized (), a major facilitator superfamily (MFS) transporter gene in . was highly expressed during infection and was upregulated by SA. The predicted three-dimensional structure of the FgMFS1 protein was consistent with the schematic for the antiporter. The subcellular localization experiment indicated that FgMFS1 was usually expressed in the vacuole of hyphae, but was alternatively distributed in the cell membrane under SA treatment, indicating an element of in response to SA. (loss of function mutant of ) showed enhanced sensitivity to SA, less pathogenicity towards wheat, and reduced DON production under SA stress. Re-introduction of a functional gene into recovered the mutant phenotypes. Wheat spikes inoculated with accumulated more SA when compared to those inoculated with the wild-type strain. Ecotopic expression of in yeast enhanced its tolerance to SA as expected, further demonstrating that FgMFS1 functions as an SA exporter. In conclusion, encodes an SA exporter in , which is critical for its response to wheat endogenous SA and pathogenicity towards wheat.