Biochemical memory in plants: A missing component in climate resilience models

Plants do not rapidly return to their pre-stress state; instead, they retain physiological and biochemical traces of past environmental conditions. Biochemical memory refers to the persistence of stress-induced metabolic and physiological states that influence how plants respond to subsequent environmental challenges. Shifts in osmolytes, redox balance, secondary metabolites, and hormonal sensitivity can persist beyond the stress event, shaping how plants respond to subsequent drought, heat, or nutrient fluctuations. Yet in most climate and vegetation models, stress is treated as a transient reduction in function, after which plants are assumed to recover to a fixed baseline. Because these models lack mechanisms to represent physiological legacies, they implicitly overlook the biochemical memory that influences growth, carbon-water exchange, and resilience. This disconnect limits our ability to predict how vegetation and ecosystems will behave under increasing climatic variability. In this Opinion, I outline how biochemical memory arises, how it influences plant behaviour across scales, and why incorporating this history into modelling frameworks is essential. Recognising that plants operate with a memory of past stress is crucial for producing realistic forecasts in a rapidly changing climate.