Table I.

Metabolism of [U-14C]Glc by cell suspension cultures of Arabidopsis

Samples (5 mL, 0.618 ± 0.017 g fresh weight) from 6-d-old cultures grown in Glc at natural abundance 13C were supplemented with 185 kBq [U-14C]Glc (yielding a specific activity of 308 ± 15 MBq mol−1) and incubated for 24 h prior to extraction in methanol and subsequent metabolic fractionation. Total 14C uptake is the sum of radioactivity in CO2, ethanol, and the chloroform-soluble, aqueous methanol-soluble, and methanol-insoluble fractions in each cell culture. Each value is the mean ± se of the distribution of radioactivity in four cell cultures.

Metabolic FractionRadioactivity in Specified Fraction
dpm
CO21,076,468 ± 35,772
Chloroform soluble63,439 ± 5,420
    Neutral lipids41,242 ± 2,217
    Free fatty acids1,083 ± 225
    Neutral P-lipids5,046 ± 722
    Acidic P-lipids21,597 ± 2,921
Methanol soluble1,021,858 ± 26,185
    Organic acids/P-esters109,533 ± 553
    Amino acids386,305 ± 13,201
        Asp/Glu31,938 ± 2,563
        Others334,737 ± 20,786
    Sugars389,986 ± 17,377
        Suc251,596 ± 16,562
        Glc58,680 ± 5,384
        Fru37,060 ± 2,298
        Others3,943 ± 623
Methanol insoluble591,272 ± 53,215
    Starch72,424 ± 11,971
    Protein116,647 ± 10,699
    Cell wall103,763 ± 13,417
    Residue77,010 ± 21,924
Ethanol18,500 ± 2,115
Total 14C uptake2,771,536 ± 67,703
Total 14C recovered2,361,265 ± 25,419
Recovery (%)84.2 ± 2.1