Proteome changes in Arabidopsis thaliana roots upon exposure to Cd2+

J Exp Bot. 2006;57(15):4003-13. doi: 10.1093/jxb/erl170. Epub 2006 Oct 30.

Abstract

Cadmium is a major environmental pollutant that enters human food via accumulation in crop plants. Responses of plants to cadmium exposure--which directly influence accumulation rates--are not well understood. In general, little is known about stress-elicited changes in plants at the proteome level. Alterations in the root proteome of hydroponically grown Arabidopsis thaliana plants treated with 10 microM Cd(2+) for 24 h are reported here. These conditions trigger the synthesis of phytochelatins (PCs), glutathione-derived metal-binding peptides, shown here as PC2 accumulation. Two-dimensional gel electrophoresis using different pH gradients in the first dimension detected on average approximately 1100 spots per gel type. Forty-one spots indicated significant changes in protein abundance upon Cd(2+) treatment. Seventeen proteins found in 25 spots were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Selected results were independently confirmed by western analysis and selective enrichment of a protein family (glutathione S-transferases) through affinity chromatography. Most of the identified proteins belong to four different classes: metabolic enzymes such as ATP sulphurylase, glycine hydroxymethyltransferase, and trehalose-6-phosphate phosphatase; glutathione S-transferases; latex allergen-like proteins; and unknown proteins. These results represent a basis for reverse genetics studies to better understand plant responses to toxic metal exposure and to the generation of internal sinks for reduced sulphur.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / drug effects
  • Arabidopsis / genetics
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Cadmium / pharmacology*
  • Electrophoresis, Gel, Two-Dimensional
  • Gene Expression Profiling
  • Glutathione / biosynthesis
  • Hydrogen-Ion Concentration
  • Phytochelatins
  • Plant Roots / drug effects
  • Plant Roots / genetics
  • Plant Roots / metabolism
  • Proteome / drug effects*
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Substances

  • Arabidopsis Proteins
  • Proteome
  • Cadmium
  • Phytochelatins
  • Glutathione