A review of recent progress on stress tolerance in tardigrades

Tardigrades are tiny semi-terrestrial animals with an extremely strong tolerance to stress. They are famous for their ability to enter the state of cryptobiosis, in which metabolism stops reversibly, providing tardigrades with the potential to survive conditions under extreme stress. Research into the mechanisms of stress tolerance and cryptobiosis in tardigrades has aroused wide attention, as the discoveries can bring enlightenments to different fields, such as the development of aerospace biotechnology. Due to its great importance, the review below aims to provide an insight into the new studies in stress tolerance in tardigrades, as this field still lacks an overview of the recent progress in these years. The essay begins with an introduction to cryptobiosis in tardigrades. It then describes progress in four parts on tardigrades stress tolerance, specifically the drought, radiation, ice, and hunger attacks. The final part summarizes and presents a vision for the future in tardigrades stress tolerance study. Besides having insights into the tardigrades' strong tolerance to extreme conditions, this paper also provides a better understanding in the future application of the potential mechanism of stress tolerance in tardigrades.