Description

To maintain cellular homeostasis, eukaryotes must control the function, quality and quantity of organelles through organelle degradation. The removal of damaged organelles is essential for plants throughout various developmental stages as well as to overcome environmental changes that enhance cellular damage, since organelle degradation allows the recycling of derived small molecules, such as amino acids, lipids and nucleic acids. During developmental aging or starvation, plants actively degrade organelles in old organs and reuse the released molecules to produce juvenile organs. This nutrient recycling can determine crop productivity under agricultural settings since various nutrients are mobilized from vegetative organs to seeds during grain filling of cereals. Overall, various types of organelle turnover systems must cooperate throughout plant development to complete their life cycle.

Autophagy is the "self-eating process" that degrades the portion of cytoplasm including organelles in eukaryotic cells. During autophagy, a nascent, double-membrane-bound vesicle called an autophagosome sequesters and transports a portion of cytoplasm into the vacuolar lumen for digestion. The molecular basis of autophagosome formation was largely demonstrated in budding yeast through the identification of autophagy-related ATG genes (ScATGs). The orthologues of ScATGs that function for autophagosome formation are conserved in plant species, and therefore the studies using the mutants of these ATG genes in model plants has helped develop our understanding of plant autophagy.

Autophagy can selectively sequester specific substrates depending on different circumstances. Recent studies have identified several types of selective autophagy processes in plant cells that degrade specific organelles or unwanted components. Thus, the aim of this Research Topic is to extend our understanding of plant autophagy processes that degrade specific organelles during plant development. We welcome the submission of Original Research, Reviews and Methods articles related to the following topics:

・Autophagic turnover processes of plant organelles (including chloroplasts, mitochondria, peroxisomes, ER, oil bodies and nuclei) throughout plant development.
・Selective elimination processes of damaged organelles in plant cells.
・Physiological roles of organelles autophagy in plant development and crop productivity.
・Relationship among autophagy and other processes for organelle turnover.