論文

国際誌
2018年

Selective Elimination of Membrane-Damaged Chloroplasts via Microautophagy

Plant Physiology
  • Nakamura, Sakuya
  • ,
  • Hidema, Jun
  • ,
  • Sakamoto, Wataru
  • ,
  • Ishida, Hiroyuki
  • ,
  • Izumi, Masanori

177
3
開始ページ
1007
終了ページ
1026
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1104/pp.18.00444
出版者・発行元
American Society of Plant Biologists ({ASPB})

Plant chloroplasts constantly accumulate damage caused by visible wavelengths of light during photosynthesis. Our previous study revealed that entire photodamaged chloroplasts are subjected to vacuolar digestion through an autophagy process termed chlorophagy; however, how this process is induced and executed remained poorly understood. In this study, we monitored intracellular induction of chlorophagy in Arabidopsis (Arabidopsis thaliana) leaves and found that mesophyll cells damaged by high visible light displayed abnormal chloroplasts with a swollen shape and 2.5 times the volume of normal chloroplasts. In wild-type plants, the activation of chlorophagy decreased the number of swollen chloroplasts. In the autophagy-deficient autophagy mutants, the swollen chloroplasts persisted, and dysfunctional chloroplasts that had lost chlorophyll fluorescence accumulated in the cytoplasm. Chloroplast swelling and subsequent induction of chlorophagy were suppressed by the application of exogenous mannitol to increase the osmotic pressure outside chloroplasts or by overexpression of VESICLE INDUCING PROTEIN IN PLASTID1, which maintains chloroplast envelope integrity. Microscopic observations of autophagy-related membranes showed that swollen chloroplasts were partly surrounded by autophagosomal structures and were engulfed directly by the tonoplast, as in microautophagy. Our results indicate that an elevation in osmotic potential inside the chloroplast due to high visible light-derived envelope damage results in chloroplast swelling and serves as an induction factor for chlorophagy, and this process mobilizes entire chloroplasts via tonoplast-mediated sequestering to avoid the cytosolic accumulation of dysfunctional chloroplasts.

リンク情報
DOI
https://doi.org/10.1104/pp.18.00444
PubMed
https://www.ncbi.nlm.nih.gov/pubmed/29748433
PubMed Central
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6052986
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000438735500016&DestApp=WOS_CPL
ID情報
  • DOI : 10.1104/pp.18.00444
  • ORCIDのPut Code : 49421458
  • PubMed ID : 29748433
  • PubMed Central 記事ID : PMC6052986
  • Web of Science ID : WOS:000438735500016

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