The <i>epigenetic engine</i> : Transgenerational plasticity as a driver of plant climate resilience and adaptation

Abstract We propose that transgenerational epigenetic inheritance (TEI), the transmission of environmental memories across generations, functions as an epigenetic engine for rapid adaptation to environmental changes. We argue that this engine serves a dual purpose: it acts as a direct, powerful mechanism for phenotypic adaptation to sudden environmental changes and as a transient bridge that maintains population viability, buying time for genetic rescue. We synthesize evidence that small RNAs, DNA methylation, and histone modifications form a coordinated circuit that converts environmental cues into stable phenotypic memories. The output of this engine is calibrated based on environmental predictability, which typically leads to adaptive outcomes. Scaling these mechanisms reveals their ecological reach: transgenerational memory reshapes species interactions and, through the transgenerational ecosystem legacy hypothesis , links epigenetic priming to nutrient cycling regimes. We introduce the dynamic clutch framework , in which TEI acts as a transient coupling between phenotypic memory and evolutionary change, facilitating short‐term ecological rescue while modulating the pace of genetic adaptation. Synthesis . By integrating molecular, ecological, and evolutionary principles, this review provides a predictive framework for understanding and harnessing non‐genetic inheritance in a rapidly changing world.