Aranjuelo Michelena, IkerCabrerizo, Pablo MaríaArrese-Igor Sánchez, CésarAparicio Tejo, Pedro María2022-11-172022-11-172013Aranjuelo, I., Cabrerizo, P. M., Arrese-Igor, C., & Aparicio-Tejo, P. M. (2013). Pea plant responsiveness under elevated [CO2] is conditioned by the N source (N2 fixation versus NO3− fertilization). Environmental and Experimental Botany, 95, 34-40.1873-7307 (Electronic)10.1016/j.envexpbot.2013.06.002https://academica-e.unavarra.es/handle/2454/44410The main goal of this study was to test the effect of [CO2] on C and N management in 2different plant organs (shoots, roots and nodules) and its implication in the 3responsiveness of exclusively N2-fixing and NO3--fed plants. For this purpose, 4exclusively N2-fixingand NO3--fed (10 mM) pea (Pisum sativumL.) plants were 5exposed to elevated [CO2] (1000 mol mol-1versus360 mol mol-1CO2). Gas 6exchange analyses, together with carbohydrate, nitrogen, total soluble proteins and 7amino acids were determined in leaves, roots and nodules. The data obtained revealed 8that although exposure to elevated [CO2] increased total dry mass (DM)in both N 9treatments, photosynthetic activity was down-regulated in NO3--fed plants, whereas N2-10fixing plants were capable of maintaining enhanced photosynthetic rates under elevated 11[CO2]. In the case of N2-fixing plants, the enhanced C sink strength of nodules enabled 12the avoidance of harmful leaf carbohydrate build up. On the other hand, in NO3--fed 13plants, elevated [CO2] caused a large increase in sucrose and starch. The increase in root 14DM did not contribute to stimulation ofC sinks in these plants. Although N2fixation 15matched plant N requirementswith the consequent increase in photosynthetic rates, in 16NO3--fed plants, exposure to elevated [CO2] negatively affected N assimilationwith the 17consequent photosynthetic down-regulation.31 p.application/pdfeng© 2013 Elsevier B.V. This manuscript version is made available under the CC-BY-NC-ND 4.0CarbonCO2LegumesNitrogenSinkinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccessAcceso abierto / Sarbide irekia