Sublethal cadmium intoxication in Arabidopsis thaliana impacts translation at multiple levels

Plant Cell Physiol. 2011 Feb;52(2):436-47. doi: 10.1093/pcp/pcr001. Epub 2011 Jan 19.

Abstract

To study the impact of translational regulation during heavy metal poisoning, Arabidopsis thaliana cell cultures were submitted to sublethal cadmium stress. At the concentration used, cadmium had a minimal impact on the growth of the culture but induced an accumulation of high molecular weight polysomes without de novo production of new ribosomes together with a reduction of protein synthesis. In addition, cadmium stress induces phosphorylation of eukaryotic initiation factor 2α by GCN2 and, in planta, gcn2 mutants are more sensitive to cadmium stress, suggesting a role for this translational regulation mechanism in the response to cadmium stress. Microarray analysis of total and polysomal RNAs in control and cadmium-treated cells reveals a large class of genes for which a variation in total RNA abundance is not linked to a variation in polysomal loading, suggesting that transcription and translation are uncoupled and that these genes are not recruited at the initiation step of translation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / drug effects
  • Arabidopsis / genetics*
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / metabolism
  • Cadmium / toxicity*
  • Cells, Cultured
  • Eukaryotic Initiation Factor-2 / metabolism
  • Gene Expression Regulation, Plant
  • Oligonucleotide Array Sequence Analysis
  • Phosphorylation
  • Polyribosomes / metabolism
  • Protein Biosynthesis / drug effects*
  • Protein Kinases / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Plant / genetics
  • RNA, Plant / metabolism
  • Stress, Physiological
  • Transcription, Genetic

Substances

  • Arabidopsis Proteins
  • Eukaryotic Initiation Factor-2
  • RNA, Messenger
  • RNA, Plant
  • Cadmium
  • Protein Kinases
  • GCN2 protein, Arabidopsis