Molecular Biology Research
To truly understand how spaceflight affects plant biology, researchers must look closer. We must turn to molecular biology and genetics.
Introduction
Your DNA is the main blueprint for your body’s biology- this is also true for plants. DNA is the “genetic code” that determines much of how a plant develops, functions, etc., but this isn’t necessarily set in stone. Genes can be expressed differently in different environments, through gene regulation, epigenetics, etc. Astrobotany researchers can look at how genes are expressed differently in spaceflight using molecular biology techniques. By understanding what is happening at the molecular level, we can gain a more thorough understanding of how spaceflight affects plant biology.
Here are some plant biology gene families that are regulated by spaceflight:
Peroxidases
Peroxidases are a large family of enzymes that catalyze oxidative reactions. They have a chemical relationship with reactive oxygen species (ROS). Two examples of ROS are hydrogen peroxide and superoxide anions. These are known to be implicated in cellular harm and are the cause of oxidative stress but interestingly, they also have a role in regulating cell elongation, division, and aging. Peroxidases can use peroxides as a substrate and subsequently can “scavenge” ROS, but they can also produce ROS in environments where autoxidation is hindered. Focusing on plant biology, some studies conclude that peroxidases play a role in plant defense against environmental stress (cold and salt), and a spaceflight experiment concluded that peroxidases’ production of ROS leads to stunted growth in root hairs.
RBOH Family
The RBOH family of proteins is involved in reactive oxygen species that are signaling molecules. RBOHs are a group of genes that are differentially expressed during spaceflight. This is based on data retrieved from BRIC 19 SpaceX CRS-4.
Strigolactones
Strigolactone is a plant hormone that stimulates branching and helpful fungi growth in root systems. In October 2018, a research paper from microgravity asserted that this chemical may help stop some of the negative effects of spaceflight microgravity and low-nutrient environments. Read more.