Unraveling the Functional Diversity of Succinate Dehydrogenase Subunits in Fusarium verticillioides

However, the roles of individual Sdh subunits in fungal development and SDHI responses remain unclear. Here, we systematically characterized Sdh subunits in Fusarium verticillioides, the causal agent of maize ear rot.

Deletion of <i>FvSdhA</i>, <i>FvSdhB</i>, or <i>FvSdhD</i> severely impaired fungal growth, conidiation, toxin production, pathogenicity, and concurrently reduced sensitivity to the SDHI fungicide pydiflumetofen. In contrast, the duplicated membrane-anchoring subunits FvSdhC1 and FvSdhC2 exhibited partial functional redundancy as deletion of <i>FvSdhC1</i> led to a dramatic upregulation of <i>FvSdhC2</i> transcript, and both could potentially support Sdh complex formation, while they exerted distinct effects on virulence and SDHI response.