Could ammonium nutrition increase plant C-sink strength under elevated CO2 conditions?
2022
Jauregui, Ivan | Rivero-Marcos, Mikel | Aranjuelo, Iker | Aparicio-Tejo, Pedro M | Lasa, Berta | Ariz, Idoia
英语. peer reviewed
显示更多 [+] 显示较少 [-]英语. Atmospheric carbon dioxide (CO2) is increasing, and this affects plant photosynthesis and biomass production. Under elevated CO2 conditions (eCO2), plants need to cope with an unbalanced carbon-to-nitrogen ratio (C/N) due to a limited C sink strength and/or the reported constrains in leaf N. Here, we present a physiological and metabolic analysis of ammonium (NH4+)-tolerant pea plants (Pisum sativum L., cv. snap pea) grown hydroponically with moderate or high NH4+ concentrations (2.5 or 10 mM), and under two atmospheric CO2 concentrations (400 and 800 ppm). We found that the photosynthetic efficiency of the NH4+ tolerant pea plants remain intact under eCO2 thanks to the capacity of the plants to maintain the foliar N status (N content and total soluble proteins), and the higher C-skeleton requirements for NH4+ assimilation. The capacity of pea plants grown at 800 ppm to promote the C allocation into mobile pools of sugar (mainly sucrose and glucose) instead of starch contributed to balancing plant C/N. Our results also support previous observations: plants exposed to eCO2 and NH4+ nutrition can increase of stomatal conductance. Considering the C and N source-sink balance of our plants, we call for exploring a novel trait, combining NH4+ tolerant plants with a proper NH4+ nutrition management, as a way for a better exploitation of eCO2 in C3 crops.
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