植物细胞(THE PLANT CELL)2013-09-05 2:57 AM

Autophagy Contributes to Leaf Starch Degradation

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.

KEYWORDS

SHARE & LIKE

COMMENTS

ABOUT THE AUTHOR

植物细胞(THE PLANT CELL)

0 Following 1 Fans 0 Projects 47 Articles

SIMILAR ARTICLES

BINDING PROTEIN (BiP) is a major chaperone in the endoplasmic reticulum (ER) lumen, and this study shows that BiP binds to the C-terminal tail of the s

Read More

Vesicle trafficking plays an important role in cell division, establishment of cell polarity, and translation of environmental cues to developmental re

Read More

The genus Brassica includes several important agricultural and horticultural crops. Their current genome structures were shaped by whole-genome triplic

Read More

Trans-acting small interfering RNAs (tasiRNAs) are a major class of small RNAs performing essential biological functions in plants. The first reported

Read More

RK5 is a member of the Arabidopsis thaliana Ca2+/calmodulin-dependent kinase-related kinase family. Here, we show that inactivation of CRK5 inhibits pr

Read More

The waxy plant cuticle protects cells from dehydration, repels pathogen attack, and prevents organ fusion during development. The transcription factor

Read More

Constrained to develop within the seed, the plant embryo must adapt its shape and size to fit the space available. Here, we demonstrate how this adjust

Read More

N-myristoylation is a crucial irreversible eukaryotic lipid modification allowing a key subset of proteins to be targeted at the periphery of specific

Read More

Exocysts are highly conserved octameric complexes that play an essential role in the tethering of Golgi-derived vesicles to target membranes in eukaryo

Read More

Apical actin filaments are crucial for pollen tube tip growth. However, the specific dynamic changes and regulatory mechanisms associated with actin fi

Read More