Regeneration and defense: unveiling the molecular interplay in plants

In both plants and animals, tissue or organ regeneration typically follows wounding, which also activates defense responses against pathogenic microbes and herbivores. Both intrinsic and environmental cues guide the molecular decisions between regeneration and defense. In animal studies, extensive research has highlighted the role of various microbes - including pathogenic, commensal, and beneficial species - in influencing the signaling interplay between immunity and regeneration. Conversely, most plant regeneration studies are conducted under sterile conditions, which leaves a gap in our understanding of how plant innate immunity influences regeneration pathways. Recent findings have begun to elucidate the roles of key defense pathways in modulating plant regeneration and the crosstalk between these two processes. These studies also explore how microbes might influence the molecular choice between defense and regeneration in plants. This review examines the molecular mechanisms governing the balance between plant regeneration and innate immunity, with a focus on the emerging role of aging and microbial interactions in shaping these processes.