This book offers a collection of information on successive steps of molecular dialogue between plants and pathogens. It additionally presents data that reflects intrinsic logic of plant-parasite interactions. New findings discussed include: host and non-host resistance, specific and non-specific elicitors, elicitors and suppressors, and plant and animal immunity. This book enables the reader to understand how to promote or prevent disease development, and allows them to systematize their own ideas of plant-pathogen interactions. It offers a more extensive scope of the problem as compared to other books in the market; presents data to allow consideration of host-parasite relationships in dynamics and reveals interrelations between pathogenicity and resistance factors; discusses beneficial plant-microbe interactions and practical aspects of molecular investigations of plant-parasite relationships; and compares historical study of common and specific features of plant immunity with animal immunity.