Novel, Moon and Mars, partial gravity simulation paradigms and their effects on the balance between cell growth and cell proliferation during early plant development

作者：Aránzazu Manzano, Raúl Herranz, Leonardus A. den Toom, Sjoerd te Slaa, Guus Borst, Martijn Visser, F. Javier Medina, Jack J. W. A. van Loon · 发表于：npj Microgravity · 年份：2018 · DOI：10.1038/s41526-018-0041-4 · 被引用次数：63 · 研究领域：Magnetic and Electromagnetic Effects、Spaceflight effects on biology、Light effects on plants

Abstract Clinostats and Random Positioning Machine (RPM) are used to simulate microgravity, but, for space exploration, we need to know the response of living systems to fractional levels of gravity (partial gravity) as they exist on Moon and Mars. We have developed and compared two different paradigms to simulate partial gravity using the RPM, one by implementing a centrifuge on the RPM (RPM HW ), the other by applying specific software protocols to driving the RPM motors (RPM SW ). The effects of the simulated partial gravity were tested in plant root meristematic cells, a system with known response to real and simulated microgravity. Seeds of Arabidopsis thaliana were germinated under simulated Moon (0.17 g ) and Mars (0.38 g ) gravity. In parallel, seeds germinated under simulated microgravity (RPM), or at 1 g control conditions. Fixed root meristematic cells from 4-day grown seedlings were analyzed for cell proliferation rate and rate of ribosome biogenesis using morphometrical methods and molecular markers of the regulation of cell cycle and nucleolar activity. Cell proliferation appeared increased and cell growth was depleted under Moon gravity, compared with the 1 g control. The effects were even higher at the Moon level than at simulated microgravity, indicating that meristematic competence (balance between cell growth and proliferation) is also affected at this gravity level. However, the results at the simulated Mars level were close to the 1 g static control. This...