Jeffery L. Dangl

I am interested in understanding the plant immune system and in also understanding how pathogens have adapted to circumvent it. We study the function of proteins encoded by "plant disease resistance genes". Most of these fall into a class of proteins that has related members which function in animal innate immunity. They are, in essence, the receptors that "recognize" pathogen encoded molecules from pathogens as diverse in life history as viruses, fungi, bacteria and aphids. The fact that this single class of proteins can condition resistance to all of these pests was the first evidence that plants have a dedicated immune receptor family. Despite their appearance as "receptors", we provided evidence supporting a novel mode of activation for the plant immune system, termed the "Guard Hypothesis". Here, the plant immune receptors do not directly recognize pathogen virulence factors as ligands, but rather recognize the action of those pathogen virulence factors on intracellular host targets. Thus, activation of the plant immune system is akin to that of animal immune systems, where "modified self" can be recognized to trigger an appropriate response. We are now concerned with understanding how pathogen virulence factors suppress plant immune function an dhow both partners evolve and adapt to each other's presence.