The integration of plant-based bioregenerative life support systems is a central objective in NASA's Moon to Mars strategy. Arabidopsis thaliana, a model organism with extensive genomic resources, serves as a key species to investigate plant resilience in extraterrestrial environments. We assessed the physiological and gene expression responses of A. thaliana (Col-0) grown in two off-world regolith simulants: LHS-2 (lunar highlands) and MGS-1 (Martian global). Plants exposed to these substrates exhibited significant reductions in root elongation, biomass, and chlorophyll content, along with elevated anthocyanin levels and transcriptional upregulation of stress-related genes including IRT1, PCS1, SOD1, and JAZ1. Evidence of jasmonic acid pathway activation and auxin signaling suppression suggests metal-induced hormonal misregulation. Our integrated analysis of morphological traits, pigment accumulation, and transcriptomic profiles reveals distinct mineral-specific stress responses, offering critical insights into substrate engineering strategies for future space agriculture.