Elevated Co2 Improves Wheat Growth When Grown Under Adequate Phosphorus Supply on an Al3+-Toxic Soil

Understanding how climate change affects the phosphorus (P) nutrition of crops grown on acid soils is important to optimize the management of and to secure future food production on these soils. This study assessed the impact of elevated CO2 (eCO2) on the P nutrition of wheat (Triticum aestivum) grown on Al3+-toxic and P-deficient soils. Aluminium-resistant wheat lines were grown under ambient (400 µmol mol-1) and elevated CO2 (800 µmol mol-1) receiving eight P rates (0-1250 mg kg-1) for 5 weeks in growth chambers. Parameters of plant growth and P nutrition were measured. Elevated CO2 enhanced shoot and root growth and total P uptake at P rates >250 mg kg-1 but not at lower rates. Although eCO2 decreased specific P uptake at P supply >250 mg kg-1, it did not significantly affect external or internal P requirements. Compared to EGA - Burke, citrate-exuding EGA - Burke TaMATE1B had greater shoot P concentration and greater specific P uptake. Under eCO2, the specific P uptake of EGA-Burke TaMATE1B was decreased less than that of EGA-Burke possibly due to the tendency of increased citrate efflux. In conclusion, eCO2 improved plant performance and total P uptake of both lines when grown in Al3+-toxic soils with high P applications. Elevated CO2 and P supply interactively affected P uptake efficiency more so in EGA-Burke than EGA - Burke TaMATE1B