Laboratory of Cell and Molecular Biology and Departments of Botany and Genetics, University of Wisconsin-Madison, WI, USA.
J Exp Bot. 2018 Feb 12;69(4):741-750. doi: 10.1093/jxb/erx234.
Chloroplast degradation during natural or stress-induced senescence requires the participation of both plastidic and extraplastidic degradative pathways. As part of the extraplastidic pathways, chloroplasts export stroma, envelope, and thylakoid proteins in membrane-bound organelles that are ultimately degraded in vacuoles. Some of these pathways, such as the formation of senescence-associated vacuoles (SAVs) and CV-containing vesicles (CCVs), do not depend on autophagy, whereas delivery of Rubisco-containing bodies (RCBs), ATI1-PS (ATG8-interacting Protein 1) bodies, and small starch-like granule (SSLG) bodies is autophagy dependent. In addition, autophagy of entire chloroplasts delivers damaged chloroplasts into the vacuolar lumen for degradation. This review summarizes the autophagy-dependent and independent trafficking mechanisms by which plant cells degrade chloroplast components in vacuoles.
在自然或胁迫诱导的衰老过程中，叶绿体的降解需要质体和质外体降解途径的参与。作为质外体途径的一部分，叶绿体将基质、包膜和类囊体蛋白输出到膜结合细胞器中，这些细胞器最终在液泡中降解。这些途径中的一些，如衰老相关液泡（SAV）和含 CV 的小泡（CCVs）的形成，不依赖于自噬，而 Rubisco 包含体（RCBs）、ATI1-PS（ATG8 相互作用蛋白 1）体和小淀粉样颗粒（SSLG）体的输送则依赖于自噬。此外，整个叶绿体的自噬将受损的叶绿体输送到液泡腔进行降解。本综述总结了植物细胞通过液泡中非依赖和依赖自噬的运输机制降解叶绿体成分的过程。
