Biomass Production and Carbohydrate Content of Arabidopsis thaliana at Atmospheric CO₂ Concentrations from 390 to 1680 µl l^-1

Abstract

The concentration dependency of the impact of elevated atmospheric CO₂ concentrations on Arabidopsis thaliana L. was studied. Plants were exposed to nearly ambient (390), 560, 810, 1240 and 1680 µl l^-1 CO₂ during the vegetative growth phase for 8 days. Shoot biomass production and dry matter content were increased upon exposure to elevated CO₂. Maximal increase in shoot fresh and dry weight was obtained at 560 µl l^-1 CO₂, which was due to a transient stimulation of the relative growth rate for up to 3 days. The shoot starch content increased with increasing CO₂ concentrations up to two-fold at 1680 µl l^-1 CO₂, whereas the contents of soluble sugars and phenolic compounds were hardly affected by elevated CO₂. The chlorophyll and carotenoid contents were not substantially affected at elevated CO₂ and the chlorophyll a/b ratio remained unaltered. There was no acclimation of photosynthesis at elevated CO₂; the photosynthetic capacity of leaves, which had completely developed at elevated CO₂ was similar to that of leaves developed in ambient air. The possible consequences of an elevated atmospheric CO₂ concentration to Arabidopsis thaliana in its natural habitat is discussed.

Key words

Arabidopsis thaliana L. carbon dioxide - biomass production - carbohydrates - photosynthesis - starch - phenolic compounds