"Scientists grow plants in lunar soil". "Researchers have grown the hardy and well-studied Arabidopsis thaliana in the nutrient-poor lunar regolith." "Arabidopsis thaliana, native to Eurasia and Africa, is a relative of mustard greens and other cruciferous vegetables like broccoli, cauliflower, and Brussels sprouts. It also plays a key role for scientists: due to its small size and ease of growth, it is one of the most studied plants in the world, used as a model organism for research into all areas of plant biology. As such, scientists already know what its genes look like, how it behaves in different circumstances, even how it grows in space."
"To grow the Arabidopsis, the team used samples collected on the Apollo 11, 12, and 17 missions, with only a gram of regolith allotted for each plant. The team added water and then seeds to the samples. They then put the trays into terrarium boxes in a clean room. A nutrient solution was added daily."
"The scientists found that the soils repelled water (were hydrophobic), causing the water to bead-up on the surface. Active stirring of the material with water was required to break the hydrophobicity and uniformly wet the soil. Once moistened, the lunar soils could be wetted by capillary action for plant culture."
"Every plant -- whether in a lunar sample or in a control -- looked the same up until about day six. After day six, however, it was clear that the plants were not as robust as the control group plants growing in volcanic ash, and the plants were growing differently depending on which type of sample they were in. The plants grew more slowly and had stunted roots; additionally, some had stunted leaves and sported reddish pigmentation."
"After 20 days, just before the plants started to flower, the team harvested the plants, ground them up, and studied the RNA. In a biological system, genes are decoded in multiple steps. First, the genes, or DNA, are transcribed into RNA. Then the RNA is translated into a protein sequence. These proteins are responsible for carrying out many of the biological processes in a living organism. Sequencing the RNA revealed the patterns of genes that were expressed, which showed that the plants were indeed under stress and had reacted the way researchers have seen Arabidopsis respond to growth in other harsh environments, such as when soil has too much salt or heavy metals."
