Effector-triggered immunity (ETI) activates both the SA and JA signaling pathways, despite their apparent antagonism. Our imaging based-analysis has discovered that these antagonistic phytohormone signaling pathways are activated in spatially distinct domains around the infection site during ETI. This apparent concentric pattern raises a new hypothesis that SA-JA antagonism functions on a spatial level to locally restrict SA-mediated defense during ETI, and also emphasizes the significance of spatial analysis in plant immunity.
