Acclimation of tomato to different carbon dioxide concentrations. Relationships between biochemistry and gas exchange during leaf development

Authors

  • J.-J. VAN OOSTEN,

    1. Molecular and Environmental Physiology, Horticulture Research International, Worthing Road, Littlehampton BN17 6LP, West Sussex, UK
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    • *

      Present address and correspondence: Commissariat a l'Energie Atomique. Départment de Physiologie Végétale et Ecosystèmes, Labouratoire du Métabolisme, Centre de Cadarache, 13108 Saint Paul Lez Durance-Cedex, France.

  • D. WILKINS,

    1. Molecular and Environmental Physiology, Horticulture Research International, Worthing Road, Littlehampton BN17 6LP, West Sussex, UK
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  • R. T. BESFORD

    1. Molecular and Environmental Physiology, Horticulture Research International, Worthing Road, Littlehampton BN17 6LP, West Sussex, UK
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summary

Tomato plants were transferred to different CO2 mole fractions (350, 700, 1050 and 1400μmol CO2 mol−1) 31 d after sowing (2% of full expansion) and the light saturated rate of photosynthesis (Pmax) of the unshaded 5th leaf was measured at either an ambient CO2 mole fraction, C2 of 350 μmol CO2 mol−1 (Pmax (350)) or at the mole fraction of CO2 at which the plants were grown. At 60% nd 95% leaf expansion, Pmax of high CO2 grown plants measured at growth CO2, was greater than the Pmax (350) of the ambient CO2 grown plants. However, by leaf maturity, Pmax(growth CO2) declined linearly as growth CO2 concentration increased. Pmax (350) of plants exposed to elevated CO2 up to 60% le f expansion had not acclimated to high CO2 At 95% leaf expansion, Pmax(350) was smaller in the high CO2 grown plants. Pmax (350) w s predicted from Rubisco in vitro carboxylation capacity using tomato Rubisco kinetic constants. By 95% leaf expansion, high CO2 grown plants showed similarities to the response of plants to low nitrogen supply, in terms of Rubisco nd chlorophyll content. The observed nd theoretical relationships between the initial slopes of the Pmax/C1 responses nd Rubisco activity were statistically equivalent. Both short-term and long-term effects of elevated CO2 on dark respiration (Rn) were also investigated at two stages of leaf development (50 nd 100% expansion). Rn (growth CO2) was smaller for the high CO2 grown plants compared with the control plants, whereas Rn (350) was either equal or greater for the plants grown in high CO2

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