Planta

, Volume 181, Issue 1, pp 91–96

A structural, functional and molecular analysis of plastids of the holoparasites Cuscuta reflexa and Cuscuta europaea

Authors

  • M. A. Machado
    • Institut für Pflanzenphysiologie der Justus-Liebig-Universität Giessen
  • K. Zetsche
    • Institut für Pflanzenphysiologie der Justus-Liebig-Universität Giessen
Article

DOI: 10.1007/BF00202329

Cite this article as:
Machado, M.A. & Zetsche, K. Planta (1990) 181: 91. doi:10.1007/BF00202329

Abstract

In the plastids of Cuscuta reflexa the number of thylakoids is strongly reduced compared with true chloroplasts and no typical grana are visible. The plastids of Cuscuta europaea lack thylakoids and the stroma is filled with either starch grains or lipid droplets. In Cuscuta reflexa both chlorophylls are present in low concentrations, while in C. europaea chlorophylls are totally absent. Light slightly stimulates the incorporation of 14CO2 in C. reflexa. This is in accordance with a low activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) which was measured in extracts of this parasite. No stimulation of 14CO2 incorporation by light was observed in C. europaea. Instead, a relatively strong incorporation was measured in darkness. Malate and aspartate were the main products of this incorporation. In agreement with these results, no Rubisco activity was detected in C. europaea but there was a moderate activity of phosphoenolpyruvate-carboxylase. The presence of the genes for both subunits of Rubisco (rbcL, rbcS) and of the gene which codes for the 32-kDa protein of photosystem II (psbA) was established for C. europaea by hybridization experiments. In both species only very small amounts of transcripts of these genes were detected.

Key words

CuscutaParasite, HoloPhotosynthesis in CuscutaPlastid genesPlastid structure in Cuscuta

Abbreviations

Rubisco

ribulose-1,5-bisphosphate carboxylase/oxygenase

PEPCase

phosphoenolpyruvate carboxylase

rbcL, rbcS

genes which code for the large and small subunits of Rubisco, respectively

psbA

gene which codes for the 32-kDa protein of photosystem II

Copyright information

© Springer-Verlag 1990