Parallel evolution in Arabidopsis populations in response to salt stress in the Cape Verde Islands

Natural variability constitutes an inexhaustible source of adaptive mechanisms. These can be uncovered through quantitative genetics approaches that reveal the genetic variants underlying their diversity. When combined with ‘omics’ analyses, these approaches enable the study of a broad spectrum of traits without prior assumptions. Untargeted metabolomic analysis has the particular advantage of detecting a wide range of metabolites, including compounds that have yet to be characterised, thereby offering a unique window into unexplored biological processes. These strategies are especially relevant in a model species such as Arabidopsis thaliana.

A collaboration between the IJPB and the CBGP (INIA-CSIC) has applied this strategy to wild populations of Arabidopsis that have recently colonised different islands of the Cape Verde archipelago. The study revealed that one island population (Santo Antão) has evolved the ability to accumulate an unknown metabolite not found in other Arabidopsis populations. This trait was traced to a mutation that inactivates a specific gene. Detailed chemical analyses, supported by predictions of the gene’s enzymatic function (it belongs to the glycoside hydrolase family), showed that this metabolite is a disaccharide composed of glucuronic acid and mannose.

Remarkably, the same loss-of-function mutation appeared independently at least once more on the neighbouring island of Fogo, suggesting an adaptive process under positive selection known as parallel evolution. Plants carrying this mutation—and accumulating the disaccharide—show increased tolerance to salt stress, a major environmental constraint in these island habitats.

Further studies are needed to fully understand the underlying biological mechanism linking this metabolite to stress tolerance.

These findings open up promising avenues for developing crop varieties better adapted to extreme environmental conditions, with clear potential for addressing the challenges of climate change.


Research developed at the Institute Jean-Pierre Bourgin for Plant Sciences in collaboration.