Characterization of an Arabidopsis thaliana mutant lacking a cytosolic non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase

Plant Mol Biol. 2006 Aug;61(6):945-57. doi: 10.1007/s11103-006-0060-5.

Abstract

Non-phosphorylating glyceraldehyde- 3-phosphate dehydrogenase (NP-GAPDH) is a conserved cytosolic protein found in higher plants. In photosynthetic cells, the enzyme is involved in a shuttle transfer mechanism to export NADPH from the chloroplast to the cytosol. To investigate the role of this enzyme in plant tissues, we characterized a mutant from Arabidopsis thaliana having an insertion at the NP-GAPDH gene locus. The homozygous mutant was determined to be null respect to NP-GAPDH, as it exhibited undetectable levels of both transcription of NP-GAPDH mRNA, protein expression and enzyme activity. Transcriptome analysis demonstrated that the insertion mutant plant shows altered expression of several enzymes involved in carbohydrate metabolism. Significantly, cytosolic phosphorylating (NAD-dependent) glyceraldehyde-3-phosphate dehydrogenase mRNA levels are induced in the mutant, which correlates with an increase in enzyme activity. mRNA levels and enzymatic activity of glucose-6-phosphate dehydrogenase were also elevated, correlating with an increase in NADPH concentration. Moreover, increased ROS levels were measured in the mutant plants. Down-regulation of several glycolytic and photosynthetic genes suggests that NP-GAPDH is important for the efficiency of both metabolic processes. The results presented demonstrate that NP-GAPDH has a relevant role in plant growth and development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / enzymology
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development
  • Carbon Dioxide / metabolism
  • Chlorophyll / metabolism
  • Cytosol / enzymology
  • Gene Expression Regulation, Developmental
  • Gene Expression Regulation, Enzymologic
  • Gene Expression Regulation, Plant
  • Glyceraldehyde 3-Phosphate Dehydrogenase (NADP+) / genetics*
  • Glyceraldehyde 3-Phosphate Dehydrogenase (NADP+) / metabolism
  • Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating) / genetics
  • Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating) / metabolism
  • Glycolysis / genetics
  • Microscopy, Fluorescence
  • Mutagenesis, Insertional
  • Mutation / genetics*
  • NADP / metabolism
  • Oligonucleotide Array Sequence Analysis
  • Phenotype
  • Photosynthesis / genetics
  • Plant Leaves / enzymology
  • Plant Leaves / genetics
  • Plant Leaves / growth & development
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Reactive Oxygen Species / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Superoxides / metabolism

Substances

  • RNA, Messenger
  • Reactive Oxygen Species
  • Superoxides
  • Chlorophyll
  • Carbon Dioxide
  • NADP
  • Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating)
  • Glyceraldehyde 3-Phosphate Dehydrogenase (NADP+)