Organ-specific quality control of plant peroxisomes is mediated by autophagy

Koki Yoshimoto (1) , Michitaro Shibata (2, 3) , Maki Kondo (2) , Kazusato Oikawa (2) , Mayuko Sato (4, 5) , Kiminori Toyooka (4, 5) , Ken Shirasu (4, 5) , Mikio Nishimura (2, 3) , Yoshinori Ohsumi (6)

1 IJPB - Institut Jean-Pierre Bourgin
2 Department of Cell Biology
3 Department of Basic Biology, School of Life Science
4 RIKEN Plant Science Center
5 RIKEN CSRS - RIKEN Center for Sustainable Resource Science [Yokohama]
6 Frontier Research Center

Peroxisomes are essential organelles that are characterized by the possession of enzymes that produce hydrogen peroxide (H2O2) as part of their normal catalytic cycle. During the metabolic process, peroxisomal proteins are inevitably damaged by H2O2 and the integrity of the peroxisomes is impaired. Here, we show that autophagy, an intracellular process for vacuolar degradation, selectively degrades dysfunctional peroxisomes. Marked accumulation of peroxisomes was observed in the leaves but not roots of autophagy-related (ATG)-knockout Arabidopsis thaliana mutants. The peroxisomes in leaf cells contained markedly increased levels of catalase in an insoluble and inactive aggregate form. The chemically inducible complementation system in ATG5-knockout Arabidopsis provided the evidence that these accumulated peroxisomes were delivered to vacuoles for degradation by autophagy. Interestingly, autophagosomal membrane structures specifically recognized the abnormal peroxisomes at the site of the aggregates. Thus, autophagy is essential for the quality control of peroxisomes in leaves and for proper plant development under natural growth conditions.

Mots clés: Organelle degradation; Quality control

Domaines: Sciences du Vivant [q-bio]

Koki Yoshimoto, Michitaro Shibata, Maki Kondo, Kazusato Oikawa, Mayuko Sato, et al.. Organ-specific quality control of plant peroxisomes is mediated by autophagy. Journal of Cell Science, 2014, 127 (6), pp.1161-1168. ⟨10.1242/jcs.139709⟩. ⟨hal-01204043⟩