DEGs affected by erucamide and predicted interaction between erucamide and indicated HrcC

Numerous Gram-negative bacterial pathogens employ the type III secretion
system (T3SS), a multi-protein injectisome, to deliver virulence proteins
into host cells and cause diseases. We uncover erucamide as a previously
unknown phytoalexin of both dicots and monocots that block the T3SS
function of multiple bacterial pathogens. Genetically impairing erucamide
accumulation or exogenous application in Arabidopsis highlighted
erucamide’s role in anti-bacterial immunity. Erucamide binds HrcC, a key
T3SS component, to block injectisome assembly. Analyses of erucamide
analogues and HrcC mutants indicated that the erucamide-HrcC binding is
required for inhibiting T3SS in vitro and anti-bacterial resistance in
plants, suggesting an essential role of erucamide-HrcC binding in disease
resistance. This work reveals a plant chemical defense that targets major
virulence machinery in bacterial pathogens.