Wilson R F, Rinne R W
United States Department of Agriculture, Agricultural Research Service, Department of Agronomy, University of Illinois at Urbana, Champaign, Illinois 61801.
Plant Physiol. 1976 Mar;57(3):375-81. doi: 10.1104/pp.57.3.375.
The metabolic activity of individual lipid classes found in developing soybean cotyledons (Glycine max.) is estimated by determining the degradation rate of the compound under given conditions. Pulse-labeling and dual substrate labeling are used to evaluate this parameter. These studies indicate first order decay kinetics for phosphatidic acid, phosphatidylinositol, phosphatidylcholine, phosphatidylethanolamine, N-acyl-phosphatidylethanolamine, diglyceride, and zero order kinetics for triglyceride in cotyledons var. "Harosoy 63" at 30 days after flowering. Decay coefficients for acyl groups and lipid-glycerol moieties within specific lipid classes from either method are comparable. Half-life (t((1/2))) calculations from the decay coefficients indicate extremely rapid turn-over rates (0.08 to 3.4 hours at 25 C) and suggest similar turnover rates of acyl groups and lipid-glycerol in diglyceride and all phospholipids except N-acylphosphatidylethanolamine where acyl groups are replaced independent of the glycerol moiety. These experiments reveal not only different metabolic activity between lipid components of soybean cotyledons, but also describe a new method for measuring lipid turnover in plants.
通过测定特定条件下化合物的降解速率，估算发育中的大豆子叶（大豆）中各类脂质的代谢活性。采用脉冲标记和双底物标记来评估该参数。这些研究表明，在开花后30天的“哈罗索伊63”品种子叶中，磷脂酸、磷脂酰肌醇、磷脂酰胆碱、磷脂酰乙醇胺、N-酰基磷脂酰乙醇胺、甘油二酯呈一级衰减动力学，而甘油三酯呈零级动力学。两种方法得到的特定脂质类别中酰基和脂质甘油部分的衰减系数具有可比性。根据衰减系数计算的半衰期（t(1/2)）表明，周转率极快（25℃下为0.08至3.4小时），并且表明甘油二酯和除N-酰基磷脂酰乙醇胺之外的所有磷脂中，酰基和脂质甘油的周转率相似，在N-酰基磷脂酰乙醇胺中，酰基的替换独立于甘油部分。这些实验不仅揭示了大豆子叶脂质成分之间不同的代谢活性，还描述了一种测量植物脂质周转率的新方法。
