ABA overly-sensitive 5 (ABO5), encoding a pentatricopeptide repeat protein required for cis-splicing of mitochondrial nad2 intron 3, is involved in the abscisic acid response in Arabidopsis

Plant J. 2010 Sep;63(5):749-65. doi: 10.1111/j.1365-313X.2010.04280.x.


To study the molecular mechanism of abscisic acid (ABA) regulation of root development, we screened the root growth of Arabidopsis mutants for sensitivity to ABA. ABA overly-sensitive 5 (ABO5/At1g51965) was identified, and was determined to encode a pentatricopeptide repeat protein required for cis-splicing of mitochondrial nad2 intron 3 (nad2 is one subunit in complex I). Under constant light conditions (24-h light/0-h dark photoperiod), abo5 mutants exhibited various phenotypes and expressed lower transcripts of stress-inducible genes, such as RD29A, COR47 and ABF2, and photosynthesis-related genes proton gradient regulation 5 (PGR5) and PGR5-likephotosynthetic phenotype (PGRL1), but higher levels of nuclear-encoded genes alternative oxidase 1a (AOX1a) and oxidative signal-inducible 1 (OXI1). Prolonged ABA treatment increased the expression of the cox2 gene in complex IV and nad genes in complex I to a higher level than no ABA treatment in the wild type, but only to a moderate level in abo5, probably because abo5 already expressed high levels of mitochondrial-encoded cox2 and nad genes under no ABA treatment. More H(2) O(2) accumulated in the root tips of abo5 than in the wild type, and H(2) O(2) accumulation was further enhanced by ABA treatment. However, these growth phenotypes and gene-expression defects were attenuated by growing abo5 plants under short-day conditions (12-h light/12-h dark photoperiod). Our results indicate that ABO5 is important in the plant response to ABA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / pharmacology*
  • Alternative Splicing
  • Arabidopsis / genetics*
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / genetics*
  • Blotting, Northern
  • Cell Nucleus / genetics
  • Gene Expression Regulation, Plant / drug effects
  • Gene Expression Regulation, Plant / radiation effects
  • Green Fluorescent Proteins / genetics
  • Hydrogen Peroxide / metabolism
  • Introns / genetics
  • Microscopy, Confocal
  • Mitochondrial Proteins / genetics*
  • Mutation
  • NADH Dehydrogenase / genetics
  • Oxidoreductases / genetics
  • Plant Growth Regulators / pharmacology
  • Plant Proteins
  • Plant Roots / genetics
  • Plant Roots / metabolism
  • Protoplasts / metabolism
  • Pyrroline Carboxylate Reductases / genetics
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcription, Genetic / drug effects


  • ABO5 protein, Arabidopsis
  • Arabidopsis Proteins
  • Mitochondrial Proteins
  • Plant Growth Regulators
  • Plant Proteins
  • pentatricopeptide repeat protein, Arabidopsis
  • Green Fluorescent Proteins
  • Abscisic Acid
  • Hydrogen Peroxide
  • Oxidoreductases
  • alternative oxidase
  • Pyrroline Carboxylate Reductases
  • delta-1-pyrroline-5-carboxylate reductase
  • NADH Dehydrogenase
  • ndhG protein, Arabidopsis

Associated data

  • RefSeq/NM_148578