Physiological and Transcriptional Responses of Arabidopsis thaliana to Simulated Lunar and Martian Regolith Substrates

TL;DR

This study investigates how Arabidopsis thaliana responds physiologically and at the gene expression level to lunar and Martian soil simulants, revealing stress responses that inform future space agriculture strategies.

Contribution

It provides novel insights into plant stress mechanisms and hormonal regulation when grown in extraterrestrial regolith simulants, aiding in substrate engineering for space farming.

Findings

Reduced root growth, biomass, and chlorophyll in plants on simulants

Upregulation of stress-related genes including IRT1, PCS1, SOD1, JAZ1

Activation of jasmonic acid pathway and suppression of auxin signaling

Abstract

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.