Impact of elevated CO₂ on growth and development of Arabidopsis thaliana L.

After germination, Arabidopsis thaliana L (cv. Landsberg) was grown at 350 mu l l(-1) (control) or 700 mu l l(-1) (elevated) CO2. Total shoot biomass at the end of the vegetative growth period was increased by 56% due to a short transient stimulation of the relative growth rate by elevated CO2 at the onset of the exposure. Thereafter the relative growth rate was comparable for both CO2 levels during the remaining vegetative part of the life cycle (0.42 g g(-1) day(-1)). Flowering architecture was not affected by elevated CO2, but seed production was 51% higher. Starch content of the shoot was substantially increased upon exposure to elevated CO2, while the soluble sugar content remained unaffected. Total nitrogen content, on a dry mass basis, was decreased at elevated CO2 mainly as a result of the increased starch content. Photosynthesis wag stimulated at elevated CO2 and no acclimation of the photosynthesis at elevated CO2 was observed. Even though the stimulation of relative growth rate was only temporary, elevated CO2 resulted in an increased fitness of Arabidopsis thaliana by an increased reproductive output.