What is the scientific value of Antarctic lichens?

Lichen is an aquatic organism. When natural conditions change, lichens will quickly change the water content in cells, and at the same time change physiological reactions such as respiration or photosynthesis accordingly to resist the harm caused by unfavorable environment. This characteristic of lichen enables it to live in extreme habitats where other plants cannot grow, such as Antarctica, the Arctic, mountainous areas and desert areas. About 8% of the earth's land surface is covered with lichen, which can grow not only on the surface of plants, rotten wood or soil, but also on the surface or inside of rocks, and even cultural relics such as concrete, glass, metal and plastic can be used as its base.

Lichens have always been considered as plants. When Carsten Borchgrevink, a British Norwegian explorer, first discovered lichens in the Antarctic Circle in 1895, he claimed that it was the first time to find "green plants" in the Antarctic. But in fact, lichen is not a plant, but an organism born of a special specialized fungus (also known as lichen fungus) and algae or cyanobacteria (also known as lichen algae). This is a pattern of reciprocal growth in nature. * * * Algae can carry out photosynthesis and provide carbohydrates necessary for growth for themselves and fungi; Lichen fungi wrap the algae in lichen by forming a specific structure, which provides a protective environment for the algae from strong radiation, drought and other harsh conditions.

Lichens grow in an extremely harsh environment, so researchers have long realized that they are the most suitable biological groups for ecological transformation of Mars or some satellites to adapt to higher plants and even human life. In 2005, the European Space Agency and the Russian Space Agency jointly sent two lichens collected from the Antarctic by the Russian "Fukuda -M2" recoverable experimental satellite, namely, Rhizocarpon geographicum and Xanthoria elegans, into space and completely exposed them in the open space for half a month. These lichens have undergone the tests of cruel conditions such as vacuum, weightlessness, drastic temperature changes and intense cosmic ray radiation. After the satellite returned to Earth, lichens were placed in a suitable environment, and it was found that they recovered their metabolic activity within 24 hours.

Therefore, as a pioneer living in the worst environment on earth, lichen undertakes the historical mission of rebuilding the atmosphere and soil system of other planets or satellites in the solar system and finally realizing alien immigration. In order to achieve this goal, we need to fully understand the life characteristics of the Antarctic suit, and then transform it through various scientific means including molecular biology technology, so that it can land on other planets to rebuild the terrestrial ecosystem.