MKS1 and infection: These findings are consistent with the results observed for AtMPK4, FvMAPK4-1 and FvMAPK4-2, which displayed high transcript levels after infection with strawberry powdery mildew, accumulated to high levels during SA treatment (Figs 8 and 9), and had stronger interactions with the MKK2, MKS1 and WRKY33 proteins (Fig 10).