A complete MAP kinase cascade controls hyphopodium formation and virulence of .

UNLABELLED

Phytopathogens develop specialized infection-related structures to penetrate plant cells during infection. Different from phytopathogens that form appressoria or haustoria, the soil-borne root-infecting fungal pathogen forms hyphopodia during infection, which further differentiate into penetration pegs to promote infection. The molecular mechanisms underlying the regulation of hyphopodium formation in remain poorly characterized. Mitogen-activated protein kinases (MAPKs) are highly conserved cytoplasmic kinases that regulate diverse biological processes in eukaryotes. Here we found that deletion of , out of the five MAPKs encoded by , significantly impaired hyphopodium formation, in vitro penetration, and pathogenicity in cotton plants. Constitutive activation of MAPK kinase (MAPKK) VdSte7 and MAPK kinase kinase (MAPKKK) VdSte11 specifically activate VdKss1. Deletion of or resulted in a phenotype similar to that of the mutant with deletion. Thus, this study demonstrates that VdSte11-VdSte7-VdKss1 is a core MAPK cascade that regulates hyphopodium formation and pathogenicity in .

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s42994-023-00102-y.