Catalase and NO CATALASE ACTIVITY1 Promote Autophagy-Dependent Cell Death in Arabidopsis

Plant Cell. 2013 Nov;25(11):4616-26. doi: 10.1105/tpc.113.117192. Epub 2013 Nov 27.

Abstract

Programmed cell death often depends on generation of reactive oxygen species, which can be detoxified by antioxidative enzymes, including catalases. We previously isolated catalase-deficient mutants (cat2) in a screen for resistance to hydroxyurea-induced cell death. Here, we identify an Arabidopsis thaliana hydroxyurea-resistant autophagy mutant, atg2, which also shows reduced sensitivity to cell death triggered by the bacterial effector avrRpm1. To test if catalase deficiency likewise affected both hydroxyurea and avrRpm1 sensitivity, we selected mutants with extremely low catalase activities and showed that they carried mutations in a gene that we named NO CATALASE ACTIVITY1 (NCA1). nca1 mutants showed severely reduced activities of all three catalase isoforms in Arabidopsis, and loss of NCA1 function led to strong suppression of RPM1-triggered cell death. Basal and starvation-induced autophagy appeared normal in the nca1 and cat2 mutants. By contrast, autophagic degradation induced by avrRpm1 challenge was compromised, indicating that catalase acted upstream of immunity-triggered autophagy. The direct interaction of catalase with reactive oxygen species could allow catalase to act as a molecular link between reactive oxygen species and the promotion of autophagy-dependent cell death.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminopeptidases / genetics
  • Aminopeptidases / metabolism
  • Arabidopsis / cytology*
  • Arabidopsis / drug effects
  • Arabidopsis / physiology*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Autophagy / drug effects
  • Autophagy / physiology*
  • Autophagy-Related Proteins
  • Bacterial Proteins / genetics
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Catalase / genetics
  • Catalase / metabolism*
  • Cell Death / drug effects
  • Cell Death / genetics
  • Hydroxyurea / pharmacology
  • Mutation
  • Oxidative Stress

Substances

  • Arabidopsis Proteins
  • Autophagy-Related Proteins
  • AvrRpm1 protein, Pseudomonas syringae
  • Bacterial Proteins
  • Carrier Proteins
  • NBR1 protein, Arabidopsis
  • CAT2 protein, Arabidopsis
  • Catalase
  • Aminopeptidases
  • Atg2 protein, Arabidopsis
  • Hydroxyurea