Résumé
Atmospheric CO2 concentration may rise up to 1000 ppm before the end of the century. In C3 plants, growth under elevated CO2 (eCO2) results in a decrease of plant nitrogen (N) content on average by 15%, leading to a serious threat to come for food security and human health. Several hypotheses have been proposed to explain the decline of N content under eCO2, including a direct effect on physiological processes associated to N uptake and assimilation. However, very few regulatory and signaling events involved in the negative effect of eCO2 on N uptake and assimilation have been identified. Here, I will present our current work describing the physiological and molecular aspects of the negative effect of eCO2 on plant mineral nutrition, and especially on root nitrate transport and assimilation. By inferring gene regulatory networks, and by exploiting genetic diversity, we investigate how eCO2 alters major signaling pathways for plant mineral nutrition, in order to propose solutions to pave the way for climate-ready crops.