Understanding the molecular basis of species adapting to high altitude is one of the main issues of evolutionary biology. Compared with low-altitude areas, the Tibetan Plateau (QTP) has extreme environments such as low temperature, low oxygen, poor soil nutrition, and strong ultraviolet radiation, making it an ideal laboratory for studying the adaptation and evolution of plants to high-altitude environments.  

Saussurea is one of the most species-rich genera in Asteraceae comprising more than 400 species. It is widely distributed in the northern hemisphere, with the highest diversity in QTP. The habitats of Saussurea species are complex and diverse, including alpine scree slopes above 5,000 meters, cold alpine meadows, grasslands and forests. Hence, Saussurea is a good system for studying high-altitude adaption of plants.   

Researchers at the Wuhan Botanical Garden of the Chinese Academy of Sciences (CAS) conducted a comparative genomics study using transcriptome sequences of five Saussurea species.    

Divergence time estimation based on genomic data revealed that Saussurea diversified during the Miocene, a period with extensive tectonic movement and climatic fluctuation on the QTP.

Besides, analysis of gene families specific to high-altitude species showed that they were significantly enriched in oxidoreductase activity, pectin catabolism, lipid transport and polysaccharide metabolism. These processes may be related to the adaptation of plants to extremely low temperatures at high altitudes.    

Furthermore, study identified hundreds of genes possessing specific traits of adaptive significance, such as membrane stabilization, response to radiation, DNA repair, and organic metabolism, which potentially responsible for Saussurea adaptation to the harsh environments of high altitude.  

This research provides reference-level genomic resources for alpine plants, while gaining important insights into how plants adapt to harsh and extreme environments.   

The results have been published on Plants with the title of "Transcriptomes of Saussurea (Asteraceae) provide insights into high-altitude adaptation." 

This research was supported by the Second Tibetan Plateau Scientific Expedition and Research program, and the Strategic Priority Research Program of CAS. 

Insights into high-altitude adaptation from transcriptomes of Saussurea (Asteraceae). (Image by WBG)