Simulated galactic cosmic ray exposure activates dose-dependent DNA repair response and down regulates glucosinolate pathways in arabidopsis seedlings

Anirudha R Dixit; Alexander D Meyers; Brian Richardson; Jeffrey T Richards; Stephanie E Richards; Srujana Neelam; Howard G Levine; Mark J Cameron; Ye Zhang

doi:10.3389/fpls.2023.1284529

Simulated galactic cosmic ray exposure activates dose-dependent DNA repair response and down regulates glucosinolate pathways in arabidopsis seedlings

Front Plant Sci. 2023 Dec 14:14:1284529. doi: 10.3389/fpls.2023.1284529. eCollection 2023.

Authors

Affiliations

¹ AETOS Systems Inc., LASSO II Contract, Huntsville, AL, United States.
² NASA Postdoctoral Program, John F. Kennedy Space Center, Merritt Island, FL, United States.
³ Case Western Reserve University, Cleveland, OH, United States.
⁴ Bionetics Corp., LASSO Contract, Merritt Island, FL, United States.
⁵ NASA John F. Kennedy Space Center, Kennedy Space Center, FL, United States.

^# Contributed equally.

Abstract

Outside the protection of Earth's magnetic field, organisms are constantly exposed to space radiation consisting of energetic protons and other heavier charged particles. With the goal of crewed Mars exploration, the production of fresh food during long duration space missions is critical for meeting astronauts' nutritional and psychological needs. However, the biological effects of space radiation on plants have not been sufficiently investigated and characterized. To that end, 10-day-old Arabidopsis seedlings were exposed to simulated Galactic Cosmic Rays (GCR) and assessed for transcriptomic changes. The simulated GCR irradiation was carried out in the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Lab (BNL). The exposures were conducted acutely for two dose points at 40 cGy or 80 cGy, with sequential delivery of proton, helium, oxygen, silicon, and iron ions. Control and irradiated seedlings were then harvested and preserved in RNAlater at 3 hrs post irradiation. Total RNA was isolated for transcriptomic analyses using RNAseq. The data revealed that the transcriptomic responses were dose-dependent, with significant upregulation of DNA repair pathways and downregulation of glucosinolate biosynthetic pathways. Glucosinolates are important for plant pathogen defense and for the taste of a plant, which are both relevant to growing plants for spaceflight. These findings fill in knowledge gaps of how plants respond to radiation in beyond-Earth environments.

Keywords: Arabidopsis; DNA damage response; galactic cosmic ray; glucosinolate pathway; space radiation; transcriptomic analysis.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This research was funded by the NASA Space Biology Program (GCR experiments in 2018 and RNAseq analysis) and the Human Research Program. SN was supported by NASA Postdoctoral Program (NNH15C048B) when conducting this experiment. AM was supported by NASA Postdoctoral Program (80HQTR21CA005).