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Abstract Eukaryotic cells have evolved membrane-bound organelles, including the endoplasmic reticulum (ER), Golgi, mitochondria, peroxisomes, chloroplasts (in plants and green algae) and lysosomes/vacuoles, for specialized functions. Organelle quality control and their proper interactions are crucial both for normal cell homeostasis and function and for environmental adaption. Dynamic turnover of organelles is tightly controlled, with autophagy playing an essential role. Autophagy is a programmed process for efficient clearing of unwanted or damaged macromolecules or organelles, transporting them to vacuoles for degradation and recycling and thereby enhancing plant environmental plasticity. The specific autophagic engulfment of organelles requires activation of a selective autophagy pathway, recognition of the organelle by a receptor, and selective incorporation of the organelle into autophagosomes. While some of the autophagy machinery and mechanisms for autophagic removal of organelles is conserved across eukaryotes, plants have also developed unique mechanisms and machinery for these pathways. In this review, we discuss recent progress in understanding autophagy regulation in plants, with a focus on autophagic degradation of membrane-bound organelles. We also raise some important outstanding questions to be addressed in the future.
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Coordination and Crosstalk between Autophagosome and Multivesicular Body Pathways in Plant Stress Responses
In eukaryotic cells, autophagosomes and multivesicular bodies (MVBs) are two closely related partners in the lysosomal/vacuolar protein degradation system. Autophagosomes are double membrane-bound organelles that transport cytoplasmic components, including proteins and organelles for autophagic degradation in the lysosomes/vacuoles. MVBs are single-membrane organelles in the endocytic pathway that contain intraluminal vesicles whose content is either degraded in the lysosomes/vacuoles or recycled to the cell surface. In plants, both autophagosome and MVB pathways play important roles in plant responses to biotic and abiotic stresses. More recent studies have revealed that autophagosomes and MVBs also act together in plant stress responses in a variety of processes, including deployment of defense-related molecules, regulation of cell death, trafficking and degradation of membrane and soluble constituents, and modulation of plant hormone metabolism and signaling. In this review, we discuss these recent findings on the coordination and crosstalk between autophagosome and MVB pathways that contribute to the complex network of plant stress responses.
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- Award ID(s):
- 1758767
- PAR ID:
- 10229826
- Date Published:
- Journal Name:
- Cells
- Volume:
- 9
- Issue:
- 1
- ISSN:
- 2073-4409
- Page Range / eLocation ID:
- 119
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3390/cells9010119
