Earth and Mars

Bryum argenteumIt is a true desert“resident”Widely distributed in arid and polar regions around the world, the Gurbantunggut Desert in China has formed a continuous networkBiological soil crustBecause the ribs in the leaves often appear red, it is namedRed moss; Also, due to the arrangement of tooth like hair like protrusions on the back of the rib, it is named "tooth rib". Behind this seemingly inconspicuous naming lies a set of survival wisdom that has undergone billions of years of evolution and refinement. From a distance, this layer of crust looks like a dark carpet on the surface of the earth, and every individual that makes up it silently tells the story of survivallegend.

Gurbantunggut Desert Environment in Xinjiang

In the Gurbantunggut Desert, surface temperatures can be scorching hot in summer, while water is scarce to the point of luxury. Faced with such a severe test, the toothed ribbed red moss has evolved an unparalleled ability to withstand dehydration. When the environment becomes dry, it can withstand itself98%The above cells dehydrate, and the plant gradually shrinks and curls, turning black brown in color, as if life has quietly left. However, this is not death, but an orderly dormancy. Once encountering moisture——Even a tiny morning dew in the desert can quickly revive in just a few seconds, causing the leaves to stretch and the greenery to reappear, and photosynthesis to restart immediately. This kind of "dry but not dead, dead and resurrected" transformation of water characteristics forces people to re-examine the true limits of life in the face of extreme drought.

What is even more surprising is that the survival ability of the toothed ribbed red moss is not limited to coping with drought. In the laboratory of scientists, this small moss has repeatedly refreshed people's understanding of the limits of life tolerance. Soak it in-160℃After being stored in liquid nitrogen for a month, it can still survive and regenerate new branches even after being removed; Let it withstand up to5000 GyDose of gamma ray radiation，It is the limit of ordinary plantsfiveMore than double，ButHumans are5-10 GyCan be fatal.butAfter radiation, the toothed ribbed red moss can still grow as if nothing happened as long as the environment returns to normal. Resistant to extreme drought, ultra-low temperature, and strong radiationThe combination of "superpowers" not only makes the toothed moss a "survival expert" on Earth, but also gives it the potential qualification to travel to extraterrestrial planets.

Phenotypic, physiological, and acetylation dynamic changes during dehydration rehydration process of Litsea moss

Based on these findings, the scientific research team of the Xinjiang Institute of Ecology and Geography of the Chinese Academy of Sciences has set their sights on more distant placesMars In experiments conducted using planetary atmosphere simulation facilities, the toothed moss was placed in a simulated Martian environment with a pressure of only about650 PaThe atmosphere is mainly composed of carbon dioxide, and the temperature is-60°Ctotwenty°CThere are intense fluctuations between them, as well as strong ultraviolet radiation. Under the combined action of multiple extreme pressures, this small moss not only survived, but also maintained its regenerative ability after recovering to suitable conditions. This is the first report on the survival ability of higher plants under simulated conditions on Mars, and it tells the world in a highly convincing way that the boundaries that life can reach may be much wider than we imagine.

What supports these amazing abilities is a precise and collaborative molecular regulatory network. Researchers have gradually uncovered the mystery of the plant's second level rehydration response using high-throughput proteomics and phosphoproteomics techniques. Originally, during the dehydration and rehydration process, the toothed ribbed mossofProtein phosphorylation is like a sophisticated molecular switch that dynamically regulates vastly different metabolic pathways. When dehydrated, cells inhibit the energy consuming process and instead strengthen antioxidant defense andDNARepair and maintain the stability of cellular structure; When rehydrated, phosphorylation modification is rapidly activated againRibosome biosynthesisAnd energy metabolism drives the comprehensive recovery of cellular function. Among them, a key antioxidant enzyme called dehydroascorbate reductase can significantly enhance its activity by phosphorylating specific amino acid sites, efficiently clearing harmful reactive oxygen species generated during dehydration and rehydration processes, and protecting cells from oxidative damage. It is these instantaneous controls that quietly occur in the microscopic world that support the breathtaking vitality of the macro level of the toothed moss.

From an evolutionary perspective, the genome of the toothed ribbed red moss contains a large amount of genetic resources for coping with extreme environments. Scientists in its genomeFound inSignificant expansion of gene families, such as enriched protein genes in late embryonic development and early embryonic developmentLight induced proteinGenes, the proteins encoded by these genes act as natural molecular shields, enveloping and protecting critical cellular structures in adversity. At the same time, its leaves have white tips at the top, which not only reflect strong light and reduce leaf temperature, but also evolve fine structures ranging from micrometer to nanometer scales, which can efficiently condense and collect water from the atmosphere, achieving a top-down intelligent water absorption mode. These physical barriers, combined with molecular strategies, form a clear and efficient overall defense system for the toothed moss in the face of extreme environments.

Global distribution of toothed ribbed moss

It is precisely these characteristics that push survival capabilities to the extreme that endow the toothed ribbed moss withThe expectation of 'interstellar pioneers'. Scientists' imagination is not wild: if one day humans hope toMars transformationTo build a livable home, perhaps we should not start with building a huge dome, but rather by scattering a handful of toothed moss reproductive bodies. This tiny plant can produce oxygen through photosynthesis, fix carbon dioxide in the Martian atmosphere, and the biological crust it forms can gradually improve the soil structure on the Martian surface, accumulate organic matter and nutrients, and create conditions for the settlement of higher plants in the future. In a gradual and rebuilding manner from the bottom ecosystem, it will slowly stain a barren red planet with the green color of life.

Xinjiang Institute of Ecology and Geography, Chinese Academy of SciencesResearch on the toothed ribbed red moss

achieve sth. with gloryCover of The Innovation magazine

Of course, there is still a long way to go from laboratory simulators to the real environment on the surface of Mars. But the performance of the toothed ribbed red moss under various extreme tests has surpassed its biological significance as a plant and become a metaphor for the potential of life. It reminds humanity of the silent yet tenacious power inherent in life when facing enormous unknowns and extreme challenges. When we squat down in the depths of the desert, gazing at this unremarkable dark carpet, perhaps what we see is the first faint green light on a distant planet someday in the future.