Plastids are essential organelles of plant cells and it is believed that plastids have arisen from an endosymbiotic event between a protoeukaryote and a photosynthetic prokaryote.

• 叶绿体是植物细胞内的一种重要细胞器，它起源于早期具有光合能力的原核生物与真核生物的内共生事件。