Is it possible to adapt our plants to climate change? The INRAE ​​researchers, coordinators of the European GrassLandscape project, believe that grasslands, a widespread ecosystem in Europe, hide the answer in the genes of their plants. These have been sampled and kept in collections for more than 40 years by researchers. Working with researchers from the Ecole Pratique des Hautes Etudes (EPHE), they used these collections to identify genes that could allow adaptation to future climate change. Their results, published March 11 in Molecular Ecology Resources, shed light on 374 genes potentially involved in this adaptation.

What if the genes of the grassland plants of tomorrow, adapted to climate change, were in researchers' collections? Grassland plants (ecosystems present in all regions of Europe) have been under the scrutiny of researchers for more than 40 years. The genetic resource centers of the European agricultural research institutes store several thousand seed samples of these plants and accurately document their origin. There is great genetic diversity in these collections that could allow adaptation to climate change.

This is what the INRAE ​​researchers wanted to study through the GrassLandscape project. Among these sample collections, they were interested in those of one of the main pastures of the prairies: the perennial ryegrass. They sought to understand the genetic origin of their natural adaptation to a wide range of environmental variations, including climatic ones. To do this, the scientists analyzed the DNA of 469 perennial ryegrass samples from all over Europe. They identified 633 pieces of DNA related to adaptation to the stress of cold winters or long summer droughts, of which 374 could be associated with a known gene. The results obtained allowed us to distinguish regions of Europe (southern half of France, Spain, Italy) where the presence of perennial ryegrass in natural meadows is probably threatened by climate change, because the genetic diversity existing in these regions is not adequate for the weather to come. Assisted migration strategies and appropriate grassland management methods should promote future adaptation of the species and limit its risk of local extinction.

The knowledge gained will also allow the creation of new varieties of perennial ryegrass with the adaptive versions of the identified genes. These varieties can be used to plant temporary meadows adapted to the future regional climates of Europe. The introduction of temporary grasslands in rotations is one of the most effective agroecological levers for the provision of multiple ecosystem services and, in particular, carbon storage in soils.