A mitochondrial protein homologous to the mammalian peripheral-type benzodiazepine receptor is essential for stress adaptation in plants

Wolfgang Frank, Kim Miriam Baar, Enas Qudeimat, Mayada Woriedh, Ali Alawady, Diah Ratnadewi, Louis Gremillon, Bernhard Grimm, Ralf Reski

Research output: Contribution to journalArticle


The cloning of abiotic stress-inducible genes from the moss Physcomitrella patens led to the identification of the gene PpTSPO1, encoding a protein homologous to the mammalian mitochondrial peripheral-type benzodiazepine receptor and the bacterial tryptophane-rich sensory protein. This class of proteins is involved in the transport of intermediates of the tetrapyrrole biosynthesis pathway. Like the mammalian homologue, the PpTSPO1 protein is localized to mitochondria. The generation of PpTSPO1-targeted moss knock-out lines revealed an essential function of the gene in abiotic stress adaptation. Under stress conditions, the PpTSPO1 null mutants show elevated H 2O2 levels, enhanced lipid peroxidation and cell death, indicating an important role of PpTSPO1 in redox homeostasis. We hypothesize that PpTSPO1 acts to direct porphyrin precursors to the mitochondria for heme formation, and is involved in the removal of photoreactive tetrapyrrole intermediates.

Original languageEnglish (US)
Pages (from-to)1004-1018
Number of pages15
JournalPlant Journal
Issue number6
Publication statusPublished - Sep 1 2007



  • Abiotic stress tolerance
  • Mitochondria
  • Physcomitrella patens
  • Reactive oxygen species
  • Tetrapyrroles

ASJC Scopus subject areas

  • Genetics
  • Plant Science
  • Cell Biology

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