Organ-specific quality control of plant peroxisomes is mediated by autophagy.
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.
RIKEN Plant Science Center, Tsurumi-ku, Yokohama 230-0045, Japan.
Kohki
K
Yoshimoto
Michitaro
M
Shibata
Maki
M
Kondo
Kazusato
K
Oikawa
Mayuko
M
Sato
Kiminori
K
Toyooka
Ken
K
Shirasu
Mikio
M
Nishimura
Yoshinori
Y
Ohsumi
D017360:Arabidopsis / Q000166:cytology / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics; D001343:Autophagy; D000071187:Autophagy-Related Protein 5; D055786:Gene Knockout Techniques; D009928:Organ Specificity; D020675:Peroxisomes / Q000378:metabolism* / Q000648:ultrastructure; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics; D018515:Plant Leaves / Q000166:cytology* / Q000235:genetics; D013312:Stress, Physiological
D029681:Arabidopsis Proteins; D000071187:Autophagy-Related Protein 5; C518662:Atg5 protein, Arabidopsis; D010744:Phosphoric Monoester Hydrolases
Autophagy; Organelle degradation; Plant leaf; Quality control