Telomere Dynamics and Oxidative Stress in Arabidopsis in the Space Radiation Environment (APEX-12)
The APEX-12 spaceflight investigation is poised to unlock crucial insights into the effects of space radiation on genome integrity, telomere length, and telomerase activity via Reactive Oxygen Species (ROS) accumulation in the plant species Arabidopsis thaliana.
The experiment will use several different mutant and overexpression lines and a wildtype control to investigate telomeres and genome oxidation. By clarifying how the space radiation environment influences telomere dynamics, this research can significantly enhance NASA’s preparedness for future long-duration missions. NASA’s understanding of how space-related stress, represented in organisms as Reactive Oxygen Species (ROS), is intricately linked to telomere and telomerase activity.
Arabidopsis thaliana seedlings will be grown in Petri plates for seven days inside a Veggie Unit aboard the International Space Station (ISS). The lighting schedule will consist of 16 hours of light followed by 8 hours of darkness.
On the seventh day, the plants will be transferred onto Petri plate lids, wrapped in aluminum foil, rapidly frozen and then transferred to the Minus Eighty Degree Laboratory Freezer (MELFI), where they will be kept at -80°C prior to transfer to Glacier for return to Earth.
A Ground Control will be conducted in a Kennedy Space Center ISS Environmental Simulator (ISSES) chamber, mimicking the conditions of the flight samples.
The APEX-12 experiment is funded through a Space Biology grant titled “Telomere Dynamics and Oxidative Stress in Arabidopsis in the Space Radiation Environment” to Principal Investigator Dr. Dorothy Shippen of Texas A&M AgriLife Research.
Related research
Telomere dynamics and oxidative stress in Arabidopsis grown in lunar regolith simulant, Front Plant Sci. 2024 Feb 16:15:1351613. doi: 10.3389/fpls.2024.1351613. eCollection 2024.
Enhanced growth on antioxidant-treated reused LMS-1 relative to fresh substrate.
(A) Representative photos of plants germinated on untreated fresh LMS-1, antioxidant cocktail treated fresh LMS-1 and antioxidant treated reused LMS-1 at 3-day post germination.
(B) Rosette area comparison between Earth soil, antioxidant washed LMS-1 and reused antioxidant washed LMS-1 18 days post-germination. P calculated as ordinary one-way ANOVA. Plot displayed as mean with SD.
(C) Leaf size comparison between Earth soil, antioxidant washed fresh LMS-1 and reused antioxidant washed LMS-1 18 days post-germination. P calculated as ordinary one-way ANOVA. Plot displayed as mean with SD.
(D) Representative photos of plants grown in Earth soil, untreated fresh LMS-1, antioxidant washed fresh LMS-1 and reused antioxidant washed LMS-1 at 34-day post germination.
(E) Stalk height comparison between plants grown in Earth soil, untreated fresh LMS-1, antioxidant washed LMS-1 and reused antioxidant washed LMS-1 at 34-day post germination. P calculated as ordinary one-way ANOVA. Plot displayed as mean with SD.
(F) Biomass comparison between plants grown in Earth soil, untreated fresh LMS-1, antioxidant washed LMS-1 and reused antioxidant washed LMS-1 at 34-day post germination. P calculated as ordinary one-way ANOVA. Plot displayed as mean with SD.
(G) Relative genome oxidation measured as genomic 8-oxoG content for 34-day-old plants grown on Earth soil, antioxidant washed LMS-1 and reused antioxidant washed LMS-1. Data displayed as violin plot with p calculated as ordinary one-way ANOVA, n = 5 with three technical repeats performed per biological sample.
(H) Individual telomere length analysis measured by PETRA conducted on 34-day-old plants grown on Earth soil, antioxidant washed fresh LMS-1 and lunar regolith simulant, and antioxidant washed reused LMS-1. Data are shown for chromosome arms 5L, 5R, 1L and 1R. Each lane represents data from an individual plant (biological replicate).
(I) Mean telomere length determined from PETRA data analyzed by WALTER. P calculated as ordinary one-way ANOVA with n = 12.
(J) Relative telomerase activity measured by Q-TRAP on 30-day-old plants grown on Earth soil, antioxidant washed fresh LMS-1, and antioxidant washed reused LMS-1 with n = 3 for Earth soil, n = 5 antioxidant washed fresh LMS-1 and n = 4 for antioxidant washed reused LMS-1. For each biological replicate, 3 technical replicates were performed. Data displayed as violin plots with p calculated as one-way ANOVA.
Astrobiology, Space Biology,
