The decline of plant mineral nutrition under rising CO2: physiological and molecular aspects of a bad deal

The elevation of atmospheric CO2 concentration has a strong impact on the phys-iology of C3 plants, far beyond photosynthesis and C metabolism. In particular, it reduces the concentrations of most mineral nutrients in plant tissues, posing major threats on crop quality, nutrient cycles, and carbon sinks in terrestrial agro-ecosystems. The causes of the detrimental effect of high CO2 levels on plant mineral status are not understood. We provide an update on the main hy-potheses and review the increasing evidence that, for nitrogen, this detrimental ef-fect is associated with direct inhibition of key mechanisms of nitrogen uptake and assimilation. We also mention promising strategies for identifying genotypes that will maintain robust nutrient status in a future high-CO2 world.

Automated summary

Elevated atmospheric CO2 concentration negatively affects C3 plant physiology beyond photosynthesis and carbon metabolism, leading to reduced mineral nutrient concentrations in plant tissues. This poses significant threats to crop quality, nutrient cycles, and carbon sinks in terrestrial agro-ecosystems. The detrimental effect on plant mineral status, particularly nitrogen, is associated with the direct inhibition of key mechanisms of nitrogen uptake and assimilation. Promising strategies for identifying genotypes that can maintain robust nutrient status in a high-CO2 world are also discussed.