Interaction of picolinamide fungicide primary metabolites UK-2A and CAS-649 with the cytochrome bc 1 complex Qi site: mutation effects and modelling in Saccharomyces cerevisiae.

Binding of UK-2A and CAS-649 at the Qi site involves similar interactions such that general cross-resistance between fenpicoxamid and florylpicoxamid is anticipated in target pathogens. Some resistance mutations reduced growth rate and could carry a fitness penalty in pathogens. However, certain changes involving G37 and L198 carry little or no growth penalty and may pose the greatest risk for resistance development in the field. © 2022 Society of Chemical Industry.