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Cadmium induces reactive oxygen species-dependent pexophagy in Arabidopsis leaves.

Calero-Muñoz, Nieves and Exposito-Rodriguez, Marino and Collado-Arenal, Aurelio M and Rodríguez-Serrano, María and Laureano-Marín, Ana M and Santamaría, M Estrella and Gotor, Cecilia and Díaz, Isabel and Mullineaux, Philip M and Romero-Puertas, María C and Olmedilla, Adela and Sandalio, Luisa M (2019) 'Cadmium induces reactive oxygen species-dependent pexophagy in Arabidopsis leaves.' Plant, Cell and Environment, 42 (9). pp. 2696-2714. ISSN 0140-7791

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Cadmium treatment induces transient peroxisome proliferation in Arabidopsis leaves. To determine whether this process is regulated by pexophagy and to identify the mechanisms involved, we analysed time course-dependent changes in ATG8, an autophagy marker, and the accumulation of peroxisomal marker PEX14a. After 3 hr of Cd exposure, the transcript levels of ATG8h, ATG8c, a, and i were slightly up-regulated and then returned to normal. ATG8 protein levels also increased after 3 hr of Cd treatment, although an opposite pattern was observed in PEX14. Arabidopsis lines expressing GFP-ATG8a and CFP-SKL enabled us to demonstrate the presence of pexophagic processes in leaves. The Cd-dependent induction of pexophagy was demonstrated by the accumulation of peroxisomes in autophagy gene (ATG)-related Arabidopsis knockout mutants atg5 and atg7. We show that ATG8a colocalizes with catalase and NBR1 in the electron-dense peroxisomal core, thus suggesting that NBR1 may be an autophagic receptor for peroxisomes, with catalase being possibly involved in targeting pexophagy. Protein carbonylation and peroxisomal redox state suggest that protein oxidation may trigger pexophagy. Cathepsine B, legumain, and caspase 6 may also be involved in the regulation of pexophagy. Our results suggest that pexophagy could be an important step in rapid cell responses to cadmium.

Item Type: Article
Uncontrolled Keywords: ATG8; cadmium; caspase; catalase; cathepsin; legumain; NBR1; peroxisomes; pexophagy; ROS
Divisions: Faculty of Science and Health
Faculty of Science and Health > Life Sciences, School of
SWORD Depositor: Elements
Depositing User: Elements
Date Deposited: 08 Mar 2022 17:30
Last Modified: 18 Aug 2022 11:37

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