Coercion in the evolution of plant–microbe communication: A perspective

Abstract

Plants and microbes are dependent on chemical signals as a means of interkingdom communication. There are two predicted paths for the evolution of these signals. Ritualization is the oft-assumed pathway for the evolution of plant–microbe communication systems. In this process, chemical signals, which benefit both receiver and sender, evolve from chemical cues, which benefit only the receiver. However, plant–microbe signaling may evolve from coercive interactions as well, a process known as sensory manipulation. Here, we aim to highlight the prevalence of coercive interactions and discuss sensory manipulation in the context of plant–microbe interactions. We present two examples of stabilized coercion: microbial coercion of plants via the release of phytohormones and plant coercion of microbes via manipulation of quorum-sensing compounds. Furthermore, we provide an evolutionary framework for the emergence of signaling from coercive plant–microbe interactions through the process of sensory manipulation. We hope that researchers will recognize the relevance of coercive interactions in plant–microbe systems and consider sensory manipulation as a plausible evolutionary trajectory for the emergence of plant–microbe signaling.