2025/12/15 by Andrew C. Schuerger, Kylee Soltez, Anna‐Lisa Paul +1 · 1 voice
Agricultural and Biological Sciences · Medicine · #Plant Molecular Biology Research #Light effects on plants #Spaceflight effects on biology
paper · doi:10.1094/phyto-11-25-0359-r
openalex publication_date 2025/12/15 · openalex created_date 2025/12/16 · openalex updated_date 2026/06/11
Bioregenerative life support systems (BLSS) are proposed for the production of food crops, water recycling, and air revitalization in future microgravity, Moon, and Mars habitats. The alternative hypothesis ( Ha) for the current study was that simulated microgravity would increase phytopathogen growth rates, potentially leading to increased levels of disease in space-based BLSS modules. Squash cotyledon leaf discs and full canopies of Arabidopsis thaliana ( At) plants were dusted with conidia from 14-day-old colonies of Golovinomyces cichoracearum ( Gc). Leaves were positioned into one of five gravity treatments: (i) adaxial leaf surfaces pointed upward ( 1g-up control), (ii) adaxial surface oriented 90° to Earth's 1g down vector ( 1g-90° control), (iii) adaxial surfaces pointed down ( 1g-down control), (iv) rotated on a 2D clinostat, or (v) randomly rotated on a 3D random positioning machine ( RPM). Inoculated squash leaf discs and At canopies were incubated on agar media for 2 or 3 days postinoculation (dpi), fixed with 3% glutaraldehyde, and imaged with SEM. The fastest growth rates on squash leaf discs were observed for germ tubes on squash leaf discs exposed to the 2D clinostat (mean = 94.2 µm at 3 dpi) and 3D RPM system (65.3 µm at 3 dpi); all three 1g controls were similar (approximately 38 to 45 µm long). The growth rates of germ tubes on At leaves under similar gravity treatments were approximately 33% of the growth rates observed on squash leaves. The results suggest that Gc conidia may germinate more rapidly and grow faster in altered gravity conditions compared with 1g controls, supporting the Ha.