Identification of physiological and molecular mechanisms mediating the response of Nitrogen nutrition to eCO2

ended

The continuous elevation of atmospheric CO2 concentration will lead to levels higher than 750 ppm at the end of the century. Such elevated atmospheric CO2 (eCO2) will impact the biology of most plants, as CO2 is a limiting factor for C3 photosynthesis. While it is predicted that eCO2 will increase biomass production in C3 plants, many studies suggest that this is actually lower than expected. In addition eCO2 impairs the mineral status of these plants, especially for nitrogen (N) and iron. This is now acknowledged as an under evaluated threat for human nutrition, as deficiencies in proteins and micronutrients are already serious health problems affecting about two billion people. The key issue addressed by NUTRIENT is to understand why eCO2 has a detrimental effect on mineral nutrition of C3 plants. This effect is not understood, but recent studies indicate that eCO2 may negatively affect physiological and/or developmental processes involved in nutrient acquisition, translocation and assimilation. This highlights a major knowledge gap on the coordination between photosynthesis and mineral nutrition in response to eCO2. NUTRIENT will tackle this issue by focussing on the effect of eCO2 on N nutrition in Arabidopsis thaliana, with the aim to identify physiological and molecular mechanisms that underlie the negative effect of eCO2 on plant proteins content. This will be achieved using an integrative systems biology approach, combining physiological and molecular analyses of N nutrition, characterisation of transport, metabolism or signalling mutants, and modelling of gene regulatory networks from transcriptomic studies. Arabidopsis is a perfect model as it shows the same negative effect of eCO2 on nutrient status as C3 crops, and offers many genetics, genomics and bioinformatics resources. NUTRIENT has great potential to contribute to Europe’s excellence and competitiveness in the world, being in line with the European and French Sustainable Development programs.