Proposed mechanism of iron uptake by <i>R</i>. <i>oryzae</i> from ferrioxamine.

<p>Deferoxamine (D) directly chelates iron from transferrin (T), resulting in ferrioxamine which binds to Fob1 and/or Fob2 proteins on the cell surface. <i>R</i>. <i>oryzae</i> then liberates Fe²⁺ iron by the actions of cell surface reductases then transported into the cell by oxidase/Ftr1 complex (A). In the absence of Fob1/Fob2 or Ftr1 proteins, the ability of <i>R</i>. <i>oryzae</i> to obtain iron from ferrioxamine is compromised and the virulence is abrogated in deferoxamine-treated mouse model (B). Sit-mediated shuttle mechanism of ferrioxamine transportation probably acts as a secondary mechanism of iron uptake from ferrioxamine.