The role of transketolase and octulose in the resurrection plant Craterostigma plantagineum

J Exp Bot. 2016 May;67(11):3551-9. doi: 10.1093/jxb/erw174. Epub 2016 Apr 29.

Abstract

Phylogenetic analysis revealed that Craterostigma plantagineum has two transketolase genes (transketolase 7 and 10) which are separated from the other transketolase genes including transketolase 3 from C. plantagineum We obtained recombinant transketolase 3, 7, and 10 of C. plantagineum and showed that transketolase 7 and 10 of C. plantagineum, but not transketolase 3, catalyse the formation of octulose-8-phosphate in vitro Transketolase 7 and 10 of C. plantagineum performed the exchange reaction that produces octulose-8-phosphate using glucose-6-phosphate and fructose-6-phosphate as substrates. Octulose is localized in the cytosol and phloem exudate analysis showed that octulose was the dominant sugar exported from the leaves to the roots.

Keywords: Octulose; photosynthesis; resurrection plants; sugar transport; transketolase..

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbohydrate Metabolism*
  • Craterostigma / enzymology
  • Craterostigma / metabolism*
  • Gas Chromatography-Mass Spectrometry
  • Plant Leaves / metabolism
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Transketolase / genetics*
  • Transketolase / metabolism

Substances

  • Plant Proteins
  • Recombinant Proteins
  • Transketolase