Functional disruption of the pentatricopeptide protein SLG1 affects mitochondrial RNA editing, plant development, and responses to abiotic stresses in Arabidopsis

Plant J. 2012 May;70(3):432-44. doi: 10.1111/j.1365-313X.2011.04883.x. Epub 2012 Jan 16.


Land plants contain a large family of genes that encode for pentatricopeptide (PPR) proteins. To date, few of these PPR proteins have been functionally characterized. In this study, we have analyzed an Arabidopsis mutant, slg1, which exhibits slow growth and delayed development. In addition, slg1 shows an enhanced response to ABA and increased tolerance to drought stress. The SLG1 gene encodes a PPR protein that is localized in mitochondria. In the slg1 mutant, RNA editing in a single site of the mitochondrial transcript nad3 is abolished. nad3 is a subunit of complex I of the electron transport chain in mitochondria. As a consequence, the NADH dehydrogenase activity of complex I in slg1 is strongly impaired and production of ATP is reduced. When responding to ABA treatment, slg1 accumulates more H(2) O(2) in its guard cells than the wild type. The slg1 mutant also has an increased expression of genes involved in the alternative respiratory pathway, which may compensate for the disrupted function of complex I and help scavenge the excess accumulation of H(2) O(2). Our functional characterization of the slg1 mutant revealed a putative link between mitochondrial RNA editing and plant responses to abiotic stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / pharmacology
  • Amino Acid Motifs
  • Amino Acid Sequence
  • Arabidopsis / drug effects
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development
  • Arabidopsis / physiology
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Base Sequence
  • Cell Division
  • Droughts
  • Gene Expression Regulation, Plant / genetics*
  • Hydrogen Peroxide / metabolism
  • Mitochondrial Proteins / genetics
  • Mitochondrial Proteins / metabolism*
  • Molecular Sequence Data
  • Mutagenesis, Insertional
  • NADH Dehydrogenase / metabolism
  • Plant Components, Aerial / drug effects
  • Plant Components, Aerial / genetics
  • Plant Components, Aerial / growth & development
  • Plant Components, Aerial / physiology
  • Plant Growth Regulators / pharmacology
  • Plant Roots / drug effects
  • Plant Roots / genetics
  • Plant Roots / growth & development
  • Plant Roots / physiology
  • RNA / genetics*
  • RNA / metabolism
  • RNA Editing / genetics*
  • RNA, Mitochondrial
  • RNA, Plant / genetics
  • Seedlings / drug effects
  • Seedlings / genetics
  • Seedlings / growth & development
  • Seedlings / physiology
  • Stress, Physiological / genetics*


  • Arabidopsis Proteins
  • Mitochondrial Proteins
  • Plant Growth Regulators
  • RNA, Mitochondrial
  • RNA, Plant
  • SLG1 protein, Arabidopsis
  • pentatricopeptide repeat protein, Arabidopsis
  • RNA
  • Abscisic Acid
  • Hydrogen Peroxide
  • NADH Dehydrogenase