Cellular and immunological effects of a novel mycotoxin from Fusarium graminearum
Plant Biology 2019 Abstract Book.
Fusarium graminearum is a fungal pathogen of diverse plant species including maize, barley and wheat. Our group recently identified two structurally similar nonribosomal peptide mycotoxins from F. graminearum. These mycotoxins are potent phytotoxins, inducing necrotic lesions and electrolyte leakage in leaves within hours of application. The mycotoxins function as virulence factors in maize, but not in wheat, raising questions as to their mode of action and host specificity. We present evidence that the mycotoxins induce rapid cell death in both monocots and dicots, but do not affect viability of yeast, bacteria or human cells. In Arabidopsis, mycotoxin-induced cell death is blocked by a cation channel inhibitor suggesting that ion transport is involved. Interestingly, the mycotoxins induce transient immune responses including callose production and defense gene induction indicating that plant cells are able to detect the presence of the toxin or its effects. Genetic analysis is ongoing to determine possible mechanisms for mycotoxin perception.