Abstract
Fusarium fungi are the cause of an array of devastating diseases affecting yield losses and accumulating mycotoxins. Fungicides can be exploited against Fusarium and deoxynivalenol (DON) production. However, Fusarium resistance to common chemicals has become a therapeutic challenge worldwide, which indicates that new control agents carrying different mechanisms of action are desperately needed. Here, we found that a nonantibiotic drug, ethylenediaminetetraacetic acid disodium salt (EDTANa(2)), exhibited various antifungal activities against Fusarium species and DON biosynthesis. The infection of wheat seeding caused by F. graminearum was suppressed over 90% at 4 mM EDTANa(2). A similar control effect was observed in field tests. Mycotoxin production assays showed DON production was significantly inhibited, 47% lower than the control, by 0.4 mM EDTANa(2). In vitro experiments revealed a timely inhibition of H(2)O(2) production as quickly as 4 h after amending cultures with EDTANa(2) and the expression of several TRI genes significantly decreased. Chitin synthases of Fusarium were Mn(2+)-containing enzymes that were strongly inhibited by Mn(2+) deficiency. EDTANa(2) inhibited chitin synthesis and destroyed the cell wall and cytomembrane integrity of Fusarium, mainly via the chelation of Mn(2+) by EDTANa(2), and thus led to Mn deficiency in Fusarium cells. Taken together, these findings uncover the potential of EDTANa(2) as a fungicide candidate to manage Fusarium head blight (FHB) and DON in agricultural production.