Origin and evolution of the plant immune system

Abstract

ContentsSummary70I.Introduction70II.Ancient associations between plants and microbes72III.Evolutionary dynamics of plant–pathogen interactions74IV.Evolutionary signature of plant–pathogen interactions74V.Origin and evolution of RLK proteins75VI.Origin and evolution of NLR proteins77VII.Origin and evolution of SA signaling78VIII.Origin and evolution of RNA‐based defense79IX.Perspectives79Acknowledgements80References80 Summary: Microbes have engaged in antagonistic associations with plants for hundreds of millions of years. Plants, in turn, have evolved diverse immune strategies to combat microbial pathogens. The conflicts between plants and pathogens result in everchanging coevolutionary cycles known as ‘Red Queen’ dynamics. These ancient and ongoing plant–pathogen interactions have shaped the evolution of both plant and pathogen genomes. With the recent explosion of plant genome‐scale data, comparative analyses provide novel insights into the coevolutionary dynamics of plants and pathogens. Here, we discuss the ancient associations between plants and microbes as well as the evolutionary principles underlying plant–pathogen interactions. We synthesize and review the current knowledge on the origin and evolution of key components of the plant immune system. We also highlight the importance of studying algae and nonflowering land plants in understanding the evolution of the plant immune system.