Sword in the woods: How plant hosts defend against vascular pathogens.

This Commentary discusses two recent papers exploring how plants combat infection by vascular pathogens via modulating lignin production and via MAP kinase signaling cascades. For instance, we do not know how the plant immune machinery recognizes diverse vascular pathogens, and whether the MKP1-MAPK-MYB cascade contributes to defense against other vascular pathogens, for example, I Ralstonia solanacearum i , I Xylella fastidiosa i , I phytoplasmas i , and vasculature-feeding insects. Pathogens also attempt to escape or overcome the host plant immune responses; therefore, unlike pathogens specifically infecting mesophyll cells, a large number of bacterial pathogens evolved to colonize the plant vascular system as their niche, so called "vascular pathogens". [Extracted from the article]