Panter R A, Boardman N K
J Lipid Res. 1973 Nov;14(6):664-71.
Isolated etioplasts from 8-day-old dark-grown pea seedlings incorporated [1-(14)C]acetate into lipid at a relatively low rate. Plastids from seedlings that had been illuminated for at least 2 hr showed an enhanced incorporation provided the plastids were illuminated during incubation with the labeled acetate. Dark incubation or the addition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) decreased the acetate-incorporating activity of the developing chloroplasts to the level observed with etioplasts. Light had a marked effect on the type of fatty acid into which acetate was incorporated by the developing chloroplasts. Unsaturated fatty acids (mostly oleic acid) accounted for 60-80% of the incorporated label if the plastids were illuminated, but in the dark or in the presence of DCMU the unsaturated acids accounted for only 0-15% of the label incorporated into lipid. The effect of ATP on incorporation was dependent on the maturity of the chloroplasts; mature pea chloroplasts were inhibited by ATP, whereas in developing plastids there was a slight stimulation by ATP. Inhibition of acetate incorporation into lipid by DCMU appears to be due to inhibition of noncyclic phosphorylation. Incorporation was restored by reduced 2,3,5,6-tetramethylphenylenediamine, which restored phosphorylation, but not by reduced N,N,N',N'-tetramethylphenylenediamine.
从8日龄黑暗生长的豌豆幼苗中分离出的黄化质体以相对较低的速率将[1-(14)C]乙酸盐掺入脂质中。如果在与标记的乙酸盐一起孵育期间对质体进行光照，那么来自已光照至少2小时的幼苗的质体显示出掺入增强。黑暗孵育或添加3-(3,4-二氯苯基)-1,1-二甲基脲（敌草隆）会使发育中的叶绿体的乙酸盐掺入活性降低到黄化质体所观察到的水平。光照对发育中的叶绿体将乙酸盐掺入的脂肪酸类型有显著影响。如果质体受到光照，不饱和脂肪酸（主要是油酸）占掺入标记的60 - 80%，但在黑暗中或存在敌草隆的情况下，不饱和酸仅占掺入脂质的标记的0 - 15%。ATP对掺入的影响取决于叶绿体的成熟度；成熟的豌豆叶绿体受到ATP的抑制，而在发育中的质体中，ATP有轻微的刺激作用。敌草隆对乙酸盐掺入脂质的抑制作用似乎是由于对非循环磷酸化的抑制。通过还原的2,3,5,6-四甲基苯二胺恢复了掺入，还原的2,3,5,6-四甲基苯二胺恢复了磷酸化，但还原的N,N,N',N'-四甲基苯二胺则没有这种作用。
