Basically, plants need soil, water and sunlight to grow. However, how would these plants survive in areas very weak gravity like the International Space Station? Japanese researchers from Tohoku University studied the behaviors of plants under microgravity by germinating seeds of cucumber in space.
Germination is a process in which a plant sprouts from a seed. It eliminates the need for soil and the plant growth depends on other external factors like water, oxygen, temperature and sometimes light. With this, plants survive by controlling the direction of their roots to maximize the resources. It can also sense gravity and redistribute hormones to stimulate growth. But the question is, how does this redistribution happen in cellular level?
From the cucumbers that were grown on the International Space Station. Researchers analyzed the role of the gravity-sensitive CsPIN1 protein to this process. In a study published in the journal, Nature Microgravity, it was revealed that the researchers put cucumber seeds in canisters especially designed for space and sent it to grow in the space station.
After getting the cucumbers in space back to Earth, the researchers utilized the staining technique to study the behavior of the plant at a cellular level. They observed the cross section of the seedlings under a microscope and learned that the CsPIN1 protein can relocalize growth under the influence of gravity.
"This result helps to explain the gravity-regulated decrease in auxin level and thereby suppression of the peg formation on the upper side of horizontally growing cucumber seedlings," Hideyuki Takahashi, a member of the Space and Adaption Biology Laboratory at the Graduate School of Life Sciences said, according to Tohoku University.
The study of the cucumbers in space further revealed that the plant was capable of forming cellular canals to transport growth hormones. The results simply proved that seeds can turn on or turn off their growth depending on the gravity to boost survival.