Analysis of Arabidopsis growth factor gene 1 (GFG1) encoding a nudix hydrolase during oxidative signaling

Planta. 2006 Jun;224(1):1-11. doi: 10.1007/s00425-005-0183-y. Epub 2005 Dec 3.

Abstract

Maintenance of pyridine nucleotide homeostasis is vital for normal growth and development of plants and animals. We demonstrate that Arabidopsis Growth Factor Gene 1 (GFG1; At4g12720) encoding a nudix hydrolase, is an NADH pyrophosphatase and ADP-ribose pyrophosphatase. The affinity for NADH and ADP-ribose indicates that this enzyme could serve as a connection between sensing cellular redox changes and downstream signaling. GFG1 transcript levels were rapidly and transiently induced during both biotic stresses imposed by avirulent pathogens and abiotic stresses like ozone and osmoticum. T-DNA knock out plants of GFG1 gene, gfg1-1, exhibit pleiotropic phenotypes such as reduced size, increased levels of reactive oxygen species and NADH, microscopic cell death, constitutive expression of pathogenesis-related genes and enhanced resistance to bacterial pathogens. The recombinant protein failed to complement the mutator deficiency in SBMutT- strain of Escherichia coli, suggesting this protein may not play a role in sanitizing the nucleotide pool. Based on rapid transcriptional changes in response to various stresses, substrate specificity of the enzyme, and analysis of the knock out mutant, we propose that GFG1 is a key gene linking cellular metabolism and oxidative signaling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Diphosphate Ribose / metabolism
  • Apoptosis
  • Arabidopsis / enzymology*
  • Arabidopsis / genetics
  • Arabidopsis / microbiology
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Arabidopsis Proteins / physiology*
  • Base Sequence
  • Escherichia coli / genetics
  • Escherichia coli Proteins / genetics
  • Genetic Complementation Test
  • Hydrogen Peroxide / pharmacology
  • Molecular Sequence Data
  • Mutation
  • NAD / metabolism
  • Oxidation-Reduction
  • Ozone / pharmacology
  • Pseudomonas syringae / physiology
  • Pyrophosphatases / genetics
  • Pyrophosphatases / metabolism
  • Pyrophosphatases / physiology*
  • Reactive Oxygen Species / metabolism
  • Signal Transduction*
  • Superoxides / pharmacology

Substances

  • Arabidopsis Proteins
  • Escherichia coli Proteins
  • Reactive Oxygen Species
  • NAD
  • Superoxides
  • Adenosine Diphosphate Ribose
  • Ozone
  • Hydrogen Peroxide
  • Pyrophosphatases
  • mutT protein, E coli
  • nudix hydrolases