Metabolism of trans-3-hexadecenoic acid in broad bean.
1. Broad bean (Vicia faba) leaves contain rather high concentrations (about 4% of total fatty acids) of the trans-3-hexadecenoic acid. 2. Amounts of the acid increase with the age of the leaves and are absent from etiolated tissue. 3. Changes in the levels of trans-delta-4-hexadecenoic acid can be produced by subjecting the intact plants to various light/dark periods. 4. Chloroplasts isolated from broad-bean leaves show high rates of fatty acid synthesis from [1-14C]acetate. Synthesis is dependent on coenzyme A and ATP but is insensitive to the addition of exogenous acyl carrier protein. 5. The pattern of acids made includes about 20% palmitic, 5% hexadeconoic, 10% stearic and 60% oleic. trans-3-Hexadecenoic acid synthesis was most active in chloroplasts from plants exposed to the dark for 5 days and light for 3 days. 6. Arsenite addition inhibited stearate formation by isolated chloroplasts but resulted in a two-fold stimulation of overall synthesis. 7. The rate of fatty acid synthesis by isolated chloroplasts paralleled the changes in endogenous trans-3-hexadecenoic acid levels in the leaves from which they were isolated.
D000085:Acetates / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism; D003624:Darkness; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D006017:Glycolipids / Q000378:metabolism; D008027:Light; D008314:Malonates / Q000378:metabolism; D009829:Oleic Acids / Q000096:biosynthesis; D010169:Palmitic Acids / Q000096:biosynthesis; D010743:Phospholipids / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D013229:Stearic Acids / Q000096:biosynthesis; D013997:Time Factors; D014280:Triglycerides / Q000378:metabolism
D000085:Acetates; D005231:Fatty Acids, Unsaturated; D006017:Glycolipids; D008314:Malonates; D009829:Oleic Acids; D010169:Palmitic Acids; D010743:Phospholipids; D013229:Stearic Acids; D014280:Triglycerides; D002734:Chlorophyll