Adaptation of Arabidopsis thaliana to the Yangtze River basin
First author:Yu-Pan Zou; Affiliations: Institute of Botany, Chinese Academy of Sciences(中科院植物所): Beijing, China
Corresponding author:Ya-Long Guo (郭亚龙)
Background: Organisms need to adapt to keep pace with (跟上) a changing environment. Examining recent range expansion aids our understanding of how organisms evolve to overcome environmental constraints. However, how organisms adapt to climate changes is a crucial biological question that is still largely unanswered. The plant Arabidopsis thaliana is an excellent system to study this fundamental question. Its origin is in the Iberian Peninsula (伊比利亚半岛) and North Africa, but it has spread to the Far East (远东), including the most south-eastern edge of its native habitats, the Yangtze River basin (长江流域), where the climate is very different.
Results: We sequenced 118 A. thaliana strains from the region surrounding the Yangtze River basin. We found that the Yangtze River basin population is a unique population and diverged about 61,409 years ago, with gene flows occurring at two different time points, followed by a population dispersion (群体离散) into the Yangtze River basin in the last few thousands of years. Positive selection analyses revealed that biological regulation processes, such as flowering time, immune and defense response processes could be correlated with the adaptation event. In particular, we found that the flowering time gene SVP has contributed to A. thaliana adaptation to the Yangtze River basin based on genetic mapping (遗传作图).
Conclusions: A. thaliana adapted to the Yangtze River basin habitat by promoting the onset of flowering, a finding that sheds light on how a species can adapt to locales with very different climates.