The interaction between the genetic plasticity of extremophilic archaea and the physicochemical chemistry of Martian regolith constitutes one of the central, yet unresolved, questions of contemporary astrobiology. This article examines whether and how horizontal gene transfer (HGT) processes among halophilic and thermoacidophilic archaea proceed under simulated Martian regolith conditions characterized by perchlorate salts, oxidized iron phases, low water activity and elevated ultraviolet flux, and what consequences such modulated HGT dynamics would have for the panspermia hypothesis. Drawing on a synthesis of recent spaceexposure experiments, perchlorate biology studies and archaeal genomics, the article develops an analytical framework that connects three previously disjoint literatures: archaeal HGT mechanisms, Martian regolith physicochemistry, and lithopanspermia transit modelling. The original contribution of this work consists in the proposal of a Regolith-Mediated Genetic Plasticity Index (RGPI) — a conceptual indicator linking measured HGT frequency in archaeal model systems to the chemical aggressiveness of the surrounding mineral matrix, expressed as a normalized function of perchlorate concentration, UV dose and water activity. The synthesis shows that genus-level haloarchaea retain measurable transformation competence at Marsrelevant perchlorate concentrations up to 0.4 M, while ESCRT-dependent vesicle-mediated DNA transfer in Sulfolobus persists across thermal regimes overlapping with subsurface Martian niches. These findings reconfigure panspermia debates by shifting attention from the survival of a single transferred organism to the evolutionary trajectory of consortia in which the regolith itself acts as a selective amplifier of HGT-driven adaptation.