Article,
Impact of elevated CO2 concentration on ultrastructure of pericarp and composition of grain in three Triticum species of different ploidy levels
Environmental and Experimental Botany, 66 (3): 451--456 (September 2009)
DOI: 10.1016/j.envexpbot.2009.04.006
Abstract
Triticum species of three ploidies were grown under ambient (375 μl/l) or elevated (FACE, 550 μl/l) CO 2 concentration CO 2 to evaluate their response to CO 2 enrichment. The consistent effect of elevated CO 2 was an increase in concentration of starch and decrease in concentration of protein in the grain. Transmission electron micrographs revealed an increase in width and area of chloroplasts, and change in shape from elliptical in ambient to round in elevated CO 2 . There was a corresponding increase in starch grain size and number in chloroplasts. The large starch grains distributed among thylakoids resulted in separation and distortion of internal membrane system in chloroplasts. The level of response was different in species of different ploidy levels. Maximum increase in starch concentration, and least decrease in protein concentration, was observed in Triticum dicoccoides , which also proved the most suitable species in terms of C:N ratio.
