2021 年 56 巻 2 号 p. 106-111
The plant hormone auxin regulates a wide range of plant growth processes. Auxin has been assumed to be involved in environmental adaptation through precise and flexible coordination among such multiple growth processes which results in various plant shapes. Existence of auxin in various plant species that have diverse morphologies supports this assumption. However, proving the involvement of auxin in environmental adaptation has been technically challenging, and the evidence for it has not been presented. Recently, full genome sequences of natural Arabidopsis thaliana populations became publicly available. These natural populations have adapted to considerably different environments and, therefore, provide us opportunities to study molecular mechanisms of adaptation using genetic approaches including genome wide association study （GWAS）. Using a combination of GWAS and a chemical biology approach, we have identified a gene, EXOCYST70A3, which regulates natural variation of root system architectures and is involved in drought resistance. This study proposes a model of studies to identify molecular bases of adaptation in plants in an integrated way that leverages chemical biology approaches.