Abstract
Solanum tuberosum L. relies heavily on in vitro propagation for pathogen-free seed tuber production; however, the transition to ex vitro environments causes severe plantlet mortality due to transplant shock. Exogenous elicitors have emerged as pivotal preconditioning tools, but their underlying molecular mechanisms remain fragmented. This systematic review aims to elucidate the translational architecture of elicitor-driven preconditioning in Solanum tuberosum, systematically organized across a tripartite continuum—(1) epigenetic chromatin plasticity, (2) transcriptomic defense reprogramming, and (3) scalable biofactory platforms (temporary immersion bioreactors and sensor-actuated aeroponics)—required to validate ex vitro physiological competence. Adhering to PRISMA 2020 guidelines for systematic reviews, we conducted a structured search across Scopus, Web of Science, and ScienceDirect (January 2010 to August 2026). Inclusion criteria targeted original research evaluating transcriptomic or epigenetic responses to in vitro elicitation in S. tuberosum. Following quality appraisal, data from 58 high-quality studies were synthesized using a critical narrative approach. The evidence is clearly stratified into our three core layers. (1) Transcriptomic Reprogramming: Exogenous elicitors systematically reactivate dormant defense networks prior to ex vitro transfer, converging strictly on salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) signaling pathways alongside reactive oxygen species (ROS) detoxification. (2) Epigenetic Plasticity: Concurrently, morphological adaptation is heavily modulated by reversible chromatin remodeling; specifically, transient DNA hypomethylation and histone acetylation ensure in vitro cellular totipotency and stress memory. (3) Translational Scalability: Automated bioreactors and aeroponic platforms provide the essential physical microenvironment to validate these molecular outcomes and reverse vitrotype disorders at commercial scales. Elicitors drive an integrated tripartite preconditioning continuum that mitigates transplant shock and enables scalable hardening. We delineate a comprehensive translational framework to the transition from empirical micropropagation to targeted, genomics-informed biofactory platforms.