AtBI-1, a plant homologue of Bax inhibitor-1, suppresses Bax-induced cell death in yeast and is rapidly upregulated during wounding and pathogen challenge

Plant J. 2000 Feb;21(4):393-9. doi: 10.1046/j.1365-313x.2000.00690.x.


Extensive searches have so far failed to identify functional plant homologues of the mammalian apoptotic machinery. Here we report the isolation and characterisation of an Arabidopsis thaliana homologue of human Bax Inhibitor-1, AtBI-1, isolated during a differential screen of plants challenged with the phytopathogen Pseudomonas syringae. AtBI is a member of a small gene family in Arabidopsis, members of which display extensive amino acid identity to human BI-1. AtBI-1 is also functionally similar to BI-1 in its ability to suppress the lethal phenotype in yeast conferred by expression of the mammalian proapoptotic protein, Bax. Expression of AtBI-1 is rapidly upregulated in plants during wounding or pathogen challenge, suggesting a role in responses to biotic and abiotic stress. AtBI-1 upregulation appears R gene independent and is not markedly affected by mutations required for specific classes of R genes. However, the accumulation of AtBI-1 message is significantly reduced in coi1, in which defence responses to insects, pathogens and wounding are compromised.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Apoptosis
  • Apoptosis Regulatory Proteins
  • Arabidopsis / genetics
  • Arabidopsis / microbiology
  • Arabidopsis / physiology*
  • Arabidopsis Proteins*
  • Cell Death
  • Gene Expression Regulation, Plant*
  • Humans
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics
  • Membrane Proteins / physiology*
  • Molecular Sequence Data
  • Plant Proteins / chemistry
  • Plant Proteins / physiology
  • Proteins*
  • Proto-Oncogene Proteins / physiology*
  • Proto-Oncogene Proteins c-bcl-2*
  • Pseudomonas / pathogenicity
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / physiology*
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Virulence
  • bcl-2-Associated X Protein


  • ATBI-1 protein, Arabidopsis
  • Apoptosis Regulatory Proteins
  • Arabidopsis Proteins
  • BAX protein, human
  • Membrane Proteins
  • Plant Proteins
  • Proteins
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • TMBIM6 protein, human
  • bcl-2-Associated X Protein