Resistance gene signaling in plants — complex similarities to animal innate immunity

During the past year several important publications have significantly enhanced our current understanding of plant disease resistance. Among the most important discoveries are the role of SGT1 in resistance (R) gene mediated defenses, mounting support for the so-called ‘guard hypothesis’ of R gene function, and providing evidence for intramolecular interactions within R proteins as a mode of signaling control. There are many emerging parallels between the plant R genes and animal innate immunity receptor complexes. Plant SGT1 shows similarity to co-chaperones of the animal Hsp90 complex, and many receptor-like R gene products appear to interact indirectly with their pathogen-derived signal. Considering these and other similarities, researchers from both fields should be looking carefully over each other’s shoulders.