Plant regeneration: From activation to fate determination.

Plants exhibit diverse regeneration strategies to heal wounds, regrow organs, and clonally propagate. These regeneration strategies depend on inductive cues such as wounding, stress or hormones initiating cell division and cell differentiation. However, wounding activates both regeneration and defence responses, and it has become clear that plants actively decide when to regenerate and what to regenerate. By integrating cell wall, hormonal, mechanical and environmental cues, plants can initiate and shape diverse regeneration outcomes such as callus formation, root regeneration, grafting and shoot formation. Here, we discuss the latest developments in how plants activate regeneration and establish a multitude of diverse regeneration outcomes. We focus on the diversity of regeneration, the trade-off between defence and regeneration, the role of signalling in fate determination and how external cues promote regeneration plasticity. Such knowledge has implications for better understanding the adaptive relevance of regeneration and for modifying fate outcomes to enhance biotechnological applications of plant regeneration.