The Wentian experiment module is the first scientific experiment module of China's space station, which is equipped with scientific facilities such as life ecology experiment cabinets, biotechnology experiment cabinets, scientific glove boxes and cryogenic storage cabinets, and variable gravity science experiment cabinets.
As early as July 2022, the experimental unit containing rice seeds and Arabidopsis thaliana seeds began to be launched, which is also the world's first research on the cultivation of rice in the whole life cycle of the space station "from seed to seed".
Rice is a staple food for about half of the world's population, and it is important to study rice cultivation in space. But there is another crop that you are probably not very familiar with - Arabidopsis, which is an ordinary grass that cannot be eaten, cannot be worn, and does not have much economic value. So what is so special about it that it can be selected as the subject of the experiment of life in space?
Arabidopsis thaliana, also known as arabecular mustard, rat ear mustard, and arabic grass, is a small flowering plant native to Europe, Central Asia, Southwest Asia and North Africa. It can be said to be famous in the world of biological experiments, it can be called the fruit fly of the plant world, and it is one of the model plants that scientists like to study the most. A lot of plant science research is done on Arabidopsis thaliana before being extended to other species.
What is a model plant? The growth cycle is short, the genome is small, it is easy to study, and it is easier to exclude interfering factors when researching, this kind of plant can be called a model plant. Arabidopsis thaliana meets all of the above conditions, it grows extremely fast, completes a life cycle in a few weeks, and it is a self-pollinating plant that guarantees genetic stability. It is also very small, does not occupy an area, can reproduce in large quantities, and the plant structure is very simple, easy to dissect and observe, it is simply a "natural choice".
So, what about Arabidopsis thaliana and rice grown in space? Rice living in space looks similar to the earth as a whole, and the microgravity environment of space has a wider direction of growth of branches and leaves, but because the seeds of plants are not only gravity-oriented but also water-oriented, the root system will grow in the direction of soil rich in water. At the same time, the phenomenon of spitting water on rice leaves is more obvious in space. The growth cycle of Arabidopsis thaliana living in space is markedly different from that on Earth, with Space Arabidopsis thaliana growing more slowly but also surviving longer.
Many flight experiments have shown that the space environment has a significant impact on the growth direction and development process of plants, such as the lack of gravity traction, the growth direction of plant roots, stems and leaves is not up and down, in addition, the problems of delayed flowering, increased water spitting, slower growth and low seed setting rate are also very prominent. Scientists selected the key genes that control flowering in advance, and by controlling the expression of these genes in plants, they designed three Arabidopsis thaliana with different flowering times, namely early flowering, normal flowering and delayed flowering, hoping to gain a deeper understanding of how space environmental factors such as microgravity act on plant flowering through their comparative studies.
As we said before, if human beings want to truly settle in space, self-sufficiency must be achieved in all aspects. So don't underestimate these inconspicuous grasses, every small step we take in space life is a big step for human beings to live in space.