This book, divided into 13 chapters, explores recent discoveries in the area of molecular plant-microbe interactions. It focuses mainly on the mechanisms controlling plant disease resistance and the cross talk among the signalling pathways involved, and the strategies used by fungi and viruses to suppress these defences. Two chapters deal with the role of symbionts (such as the symbiotic actinobacteria and vesicular arbuscular mycorrhizal fungi) during their interactions with plants.