Photosynthesis, growth and structural characteristics of holm oak resprouts originated from plants grown under elevated CO2

Authors

  • Xavier Aranda,

    1. Departament de Biologia Vegetal, Unitat Fisiologia Vegetal, Facultat Biologia, Universitat de Barcelona, Diagonal 645, E-08028, Barcelona, Spain
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    • 1

      Present address: Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. de Cabrils s/n, 08348 Cabrils, Spain

  • Cristina Agustí,

    1. Departament de Biologia Vegetal, Unitat Fisiologia Vegetal, Facultat Biologia, Universitat de Barcelona, Diagonal 645, E-08028, Barcelona, Spain
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  • Richard Joffre,

    1. Dream Unit, Centre d’Ecologie Fonctionnelle et Evolutive CNRS, 1919 Route de Mende, 34293 Montpellier cedex 5, France
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  • Isabel Fleck

    Corresponding author
    1. Departament de Biologia Vegetal, Unitat Fisiologia Vegetal, Facultat Biologia, Universitat de Barcelona, Diagonal 645, E-08028, Barcelona, Spain
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e-mail: ifleck@ub.edu

Abstract

The physiological characteristics of holm oak (Quercus ilex L.) resprouts originated from plants grown under current CO2 concentration (350 μl l−1) (A-resprouts) were compared with those of resprouts originated from plants grown under elevated CO2 (750 μl l−1) (E-resprouts). At their respective CO2 growth concentration, no differences were observed in photosynthesis and chlorophyll fluorescence parameters between the two kinds of resprout. E-resprouts appeared earlier and showed lower stomatal conductance, higher water-use efficiency and increased growth (higher leaf, stem and root biomass and increased height). Analyses of leaf chemical composition showed the effect of elevated [CO2] on structural polysaccharide (higher cellulose content), but no accumulation of total non-structural carbohydrate on area or dry weight basis was seen. Four months after appearance, downregulation of photosynthesis and electron transport components was observed in E-resprouts: lower photosynthetic capacity, photosystem II quantum efficiency, photochemical quenching of fluorescence and relative electron transport rate. Reduction in ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCo) activity, deduced from the maximum carboxylation velocity of RuBisCo, accounts for the observed acclimation. Increased susceptibility of photosynthetic apparatus to increasing irradiance was detected in E-resprouts.

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