Funneliformis mosseae Improves Growth and Nutrient Accumulation in Wheat by Facilitating Soil Nutrient Uptake under...

The concurrent effect of elevated CO₂ (eCO₂) concentrations and arbuscular mycorrhizal fungi (AMF) on plant growth, carbon (C), nitrogen (N), phosphorus (P) and potassium (K) accumulations in plant and soil is largely unknown. To understand the mechanisms of eCO₂ and mycorrhization on wheat (Triticum aestivum) performance and soil fertility, wheat seedlings were grown under four different CO₂ environments for 12 weeks, including (1) ambient CO₂ (ACO₂, 410/460 ppm, daytime/nighttime), (2) sole daytime eCO₂ (DeCO₂, 550/460 ppm), (3) sole nighttime eCO₂ (NeCO₂, 410/610 ppm), and (4) dual or continuous daytime/nighttime eCO₂ ((D + N)eCO₂, 550/610 ppm), and with or without AMF (Funneliformis mosseae) colonization. DeCO₂, NeCO₂ and (D + N)eCO₂ generally significantly increased shoot and root biomass, plant C, N, P and K accumulation, soil invertase and urease activity, but decreased shoot and root N, P and K concentrations, and soil available N, P and K. Compared with non-AMF, AMF effects on above-mentioned characteristics were significantly positive under ACO₂, DeCO₂ and (D + N)eCO₂, but negative on plant biomass, C, N, P and K accumulation under NeCO₂. Overall, AMF colonization alleviated soil nutrient constraints on plant responses to DeCO₂, while NeCO₂ decreased AMF's beneficial effects on plants. These results demonstrated that an integration of AMF's benefits to plants under factual field DeCO₂ and/or NeCO₂ will be critical for managing the long-term consequence of future CO₂ rising on global cropping systems.