Planta

, Volume 222, Issue 5, pp 777–786

Biochemical properties of isoprene synthase in poplar (Populus × canescens)

  • J.-P. Schnitzler
  • I. Zimmer
  • A. Bachl
  • M. Arend
  • J. Fromm
  • R. J. Fischbach
Original Article

DOI: 10.1007/s00425-005-0022-1

Cite this article as:
Schnitzler, JP., Zimmer, I., Bachl, A. et al. Planta (2005) 222: 777. doi:10.1007/s00425-005-0022-1

Abstract

Isoprene synthase (ISPS) catalyzes the elimination of pyrophosphate from dimethylallyl diphosphate (DMADP) forming isoprene, a volatile hydrocarbon emitted from many plant species to the atmosphere. In the present work, immunological techniques were applied to study and localize ISPS in poplar leaves (Populus × canescens). Immunogold labeling using polyclonal antibodies generated against His-tagged recombinant ISPS protein detected ca. 44% of ISPS in the stroma of the chloroplasts and ca. 56% of gold particles attached to the stromal-facing side of the thylakoid membranes. ISPS isolated from leaves exhibited the same biochemical properties as the recombinant ISPS without the plastid-targeting peptide heterologous expressed in E. coli, whereas an additional C- or N-terminal His-tag changed the biochemical features of the recombinant enzyme with regard to temperature, pH, and substrate dependence. In comparison to the closely related class of monoterpene synthases from angiosperms and ISPS of oaks, the most striking feature of the poplar ISPS is a cooperative substrate dependence which is characteristic to enzymes with positive substrate activation. The detection of four immunoreactive bands in poplar leaf extracts with isoelectric points from 5.0 to 5.5 and a native molecular weight of ca. 51 kDa give reason for future studies on post-translational modifications of ISPS.

Keywords

IsopreneIsoprene synthase (immunohistochemistry)PoplarPopulusVolatile organic compounds

Abbreviations

DOXP/MEP

1-deoxy- D-xylulose 5-phosphate/2- C-methyl-D-erythritol 4-phosphate

DMADP

Dimethylallyl diphosphate

ISPS

Isoprene synthase

VOC

Volatile organic compounds

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • J.-P. Schnitzler
    • 1
  • I. Zimmer
    • 1
  • A. Bachl
    • 1
  • M. Arend
    • 2
  • J. Fromm
    • 2
  • R. J. Fischbach
    • 1
  1. 1.Forschungszentrum Karlsruhe GmbH, Institut für Meteorologie und KlimaforschungAtmosphärische Umweltforschung (IMK-IFU)Garmisch-PartenkirchenGermany
  2. 2.Fachgebiet HolzbiologieTechnische Universität MünchenMünchenGermany