What was done
The authors grew two varieties of wheat (Triticum aestivum) for close to a month in greenhouses receiving atmospheric CO2 concentrations of 350 and 900 ppm to study the effects of elevated CO2 on early growth and development in this important cereal crop.  In addition, half of the plants of each variety were vernalized to determine whether or not a "cold temperature exposure" would influence any CO2-induced developmental responses.

What was learned
At the conclusion of the experiment, CO2-enriched plants displayed dry weights that were 52 to 93% greater than those exhibited by ambiently-grown plants, depending upon variety and vernalization treatment.  A good portion of this dry weight increase resulted from the production of larger leaves on CO2-enriched plants, which were 39 to 82% bigger than leaves on plants grown at ambient CO2.

In scrutinizing leaves at the cellular level, it was determined that elevated CO2 caused an increase in the number of mesophyll cell layers, thereby increasing leaf thickness and structural carbon content.  Moreover, elevated CO2 significantly increased rates of cell division and elongation, thereby increasing leaf expansion and biomass production, even within the first week of differential CO2 treatment.

What it means
As the atmospheric CO2 concentration increases, it is likely that wheat plants will begin to reap benefits from this phenomenon almost immediately after seedling emergence.  Rising CO2 levels should increase cell division and elongation, thus spurring leaf expansion and biomass production to a greater degree than what is occurring under today's ambient CO2 concentration.  Thus, it is likely that these collective responses will result in larger plants, which should also produce greater harvestable yields, as the CO2 content of the air continues to rise.