Table II.

Effect of decreased aconitase activity on photosynthetic carbon partitioning at the onset of illumination

Leaf discs were cut from four separate plants of each genotype at the end of the night and illuminated at a PFD of 400 μmol photons m-2 s-1 of photosynthetically active radiation in an oxygen electrode chamber containing air saturated with 14CO2. After 30 min, the leaf discs were extracted and fractionated. Values presented are the mean ± se of measurements from six plants per genotype. Asterisks and bold type indicates those that were determined by the Student's t test to be significantly different between genotypes.

Parameter Total Uptake Starch Soluble Sugars Amino Acids Organic Acids
Label incorporated (Bq)
    Lp 550.4 ± 30.2 176.2 ± 16.1 266.8 ± 28.2 53.3 ± 5.0 54.0 ± 3.9
    Aco-1 666.7 ± 29.1* 231.8 ± 20.5* 339.2 ± 26.6* 47.8 ± 4.8 47.7 ± 5.1
Redistribution of radiolabel (as percentage of total assimilated)
    Lp 32.9 ± 3.3 47.3 ± 3.2 9.7 ± 0.9 10.0 ± 0.7
    Aco-1 35.2 ± 3.1 50.4 ± 2.4 7.3 ± 0.7* 7.2 ± 0.8*