Red Light Enhances Plant Adaptation to Spaceflight and Mars g-Levels.

Area of Science:

• Plant biology
• Space biology
• Genomics

Background:

• Space exploration requires understanding plant adaptation to extraterrestrial conditions.
• Microgravity causes detrimental effects on plant development, including root meristem issues and gene reprogramming.
• Plants can complete their life cycle in space, necessitating research into compensatory environmental cues like light.

Purpose of the Study:

• Investigate the interplay between light and gravity sensing in plants under space conditions.
• Determine if light can mitigate the negative impacts of microgravity on plant development.
• Explore directed-mutagenesis strategies for space crop design.

Main Methods:

• Conducted spaceflight experiments (NASA-ESA Seedling Growth series, 2013-2018) using different gravity levels (micro-g, Mars-g, Earth-g).
• Utilized transcriptomic studies to analyze gene expression changes in response to light and gravity.
• Examined mutant lines of nucleolin for differential responses to red light photoactivation.

Main Results:

• Red light partially reversed microgravity-induced gene reprogramming in space-flown seedlings.
• Microgravity led to increased plastid and mitochondrial gene expression, indicating disrupted nucleus-organelle communication.
• Seedlings at Mars-g exhibited activated stress response and acclimation pathways, suggesting partial-g adaptation.

Conclusions:

• Light, particularly red light, can partially counteract microgravity's negative effects on plant gene expression.
• Disrupted nucleus-organelle communication and altered hormone pathways are key responses to microgravity.
• Plants demonstrate acclimation capabilities in partial gravity (Mars-g) through genome expression modulation.