Growing on calcareous soils and facing climate change

Soil calcium carbonate (CaCO₃) impacts plant mineral nutrition far beyond Fe metabolism, imposing constraints for crop growth and quality in calcareous agrosystems. Our knowledge on plant strategies to tolerate CaCO₃ effects mainly refers to Fe acquisition. This review provides an update on plant cellular and molecular mechanisms recently described to counteract the negative effects of CaCO₃ in soils, as well as recent efforts to identify genetic bases involved in CaCO₃ tolerance from natural populations, that could be exploited to breed CaCO₃-tolerant crops. Finally, we review the impact of environmental factors (soil water content, air CO₂, and temperature) affecting soil CaCO₃ equilibrium and plant tolerance to calcareous soils, and we propose strategies for improvement in the context of climate change.