MITOCHONDRIA INCREASE 3-FOLD AND MITOCHONDRIAL PROTEINS AND LIPID CHANGE DRAMATICALLY IN POSTMERISTEMATIC CELLS IN YOUNG WHEAT LEAVES GROWNIN ELEVATED CO2

A dramatic stimulation in mitochondrial biogenesis during the very ear ly stages of leaf development was observed in young wheat plants (Trit icum aestivum cv Hereward) grown in elevated CO2 (650 mu L L(-1)). An almost 3-fold increase in the number of mitochondria was observed in t he very young leaf cells at the base of the first leaf of a 7-d-old wh eat plant. In the same cells large increases in the accumulation of a mitochondrial chaperonin protein and the mitochondrial 2-oxoglutarate dehydrogenase complex and pyruvate dehydrogenase complex were detected by immunolabeling. Furthermore, the basal segment also shows a large increase in the rate of radiolabeling of diphosphatidylglycerol, a lip id confined to the inner mitochondrial membrane. This dramatic respons e in very young leaf cells to elevated CO2 suggests that the numerous documented positive effects of elevated CO2 on wheat leaf development are initiated as early as 12 h postmitosis.