TCP three-way handshake: linking developmental processes with plant immunity

• The roles of TCP factors in plant immunity are discussed.
• We shed light on the function of TCP factors in hormonal homeostasis.
• We propose a model in which TCP factors are convergent points in the plant immune system.
• We discuss the global regulation of TCP proteins at transcriptional and post-transcriptional levels.

The TCP gene family encodes plant-specific transcription factors involved in growth and development. Equally important are the interactions between TCP factors and other pathways extending far beyond development, as they have been found to regulate a variety of hormonal pathways and signaling cascades. Recent advances reveal that TCP factors are targets of pathogenic effectors and are likely to play a vital role in plant immunity. Our focus is on reviewing the involvement of TCP in known pathways and shedding light on other linkages in the nexus of plant immunity centered around TCP factors with an emphasis on the convergence of effectors, interconnected hormonal networks, utility of the circadian clock, and the potential mechanisms by which pathogen defense may occur.