In plant cells, phosphatidylcholine (PC) is a major glycerolipid of most membranes but practically lacking from the plastid internal membranes. In chloroplasts, PC is absent from the thylakoids and the inner envelope membrane. It is however the main component of the outer envelope membrane, where it exclusively distributes in the outer monolayer. This unique distribution is likely related with operational compartmentalization of plant lipid metabolism. In this review, we summarize the different mechanisms involved in homeostasis of PC in plant cells. The specific origin of chloroplast PC is examined and the involvement of the P4-ATPase family of phospholipid flippases (ALA) is considered with a special attention to the recently reported effect of the endoplasmic reticulum-localized ALA10 on modification of chloroplast PC desaturation. The different possible roles of chloroplast PC are then discussed and analyzed in consideration of plant physiology.

在植物细胞中，磷脂酰胆碱（PC）是大多数膜的主要甘油脂，但实际上缺乏质体内部膜。在叶绿体中，类囊体和内膜没有PC。然而，它是外壳膜的主要组成部分，仅在外部单层中分布。这种独特的分布可能与植物脂质代谢的操作分区有关。在这篇综述中，我们总结了植物细胞中PC稳态所涉及的不同机制。检查了叶绿体PC的特定来源，并考虑了磷脂flippases（ALA）的P4-ATPase家族的参与，特别注意最近报道的内质网定位的ALA10对叶绿体PC脱饱和修饰的影响。