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Autophagy contributes to leaf starch degradation.
- Source :
-
The Plant cell [Plant Cell] 2013 Apr; Vol. 25 (4), pp. 1383-99. Date of Electronic Publication: 2013 Apr 05. - Publication Year :
- 2013
-
Abstract
- Transitory starch, a major photosynthetic product in the leaves of land plants, accumulates in chloroplasts during the day and is hydrolyzed to maltose and Glc at night to support respiration and metabolism. Previous studies in Arabidopsis thaliana indicated that the degradation of transitory starch only occurs in the chloroplasts. Here, we report that autophagy, a nonplastidial process, participates in leaf starch degradation. Excessive starch accumulation was observed in Nicotiana benthamiana seedlings treated with an autophagy inhibitor and in autophagy-related (ATG) gene-silenced N. benthamiana and in Arabidopsis atg mutants. Autophagic activity in the leaves responded to the dynamic starch contents during the night. Microscopy showed that a type of small starch granule-like structure (SSGL) was localized outside the chloroplast and was sequestered by autophagic bodies. Moreover, an increased number of SSGLs was observed during starch depletion, and disruption of autophagy reduced the number of vacuole-localized SSGLs. These data suggest that autophagy contributes to transitory starch degradation by sequestering SSGLs to the vacuole for their subsequent breakdown.
- Subjects :
- Adenine analogs & derivatives
Adenine pharmacology
Arabidopsis genetics
Arabidopsis metabolism
Gene Expression Profiling
Gene Expression Regulation, Plant drug effects
Gene Silencing
Hydrolysis
Luminescent Proteins genetics
Luminescent Proteins metabolism
Microscopy, Confocal
Microscopy, Electron, Transmission
Molecular Sequence Data
Mutation
Phagosomes drug effects
Phagosomes genetics
Phagosomes metabolism
Plant Leaves genetics
Plant Leaves ultrastructure
Plant Proteins genetics
Plants, Genetically Modified
Reverse Transcriptase Polymerase Chain Reaction
Seedlings drug effects
Seedlings genetics
Seedlings metabolism
Starch ultrastructure
Nicotiana genetics
Nicotiana metabolism
Autophagy
Plant Leaves metabolism
Plant Proteins metabolism
Starch metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1532-298X
- Volume :
- 25
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- The Plant cell
- Publication Type :
- Academic Journal
- Accession number :
- 23564204
- Full Text :
- https://doi.org/10.1105/tpc.112.108993