Phosphoenol Pyruvate Carboxylase in Parasitic Plants: Further Characterization in Various Species and Localization at the Level of Cells and Tissues in Lathraea clandestina L.

Phosphoenolpyruvate carboxylase (PEP carboxylase, EC 4.1.1.31) activity was demonstrated in a range of holo and hemiparasitic phanerogams. Lathraea clandestina was used as a model for a more detailed study. Enzyme activity levels were determined in the various plant parts. Great changes in enzyme capacity were observed in the shoots according to the time of measurement during a 24 hr cycle. PEP carboxylase characterized at the cellular level by using an indirect immunofluorescence method was found to be mainly located in the cytosol. The possible functions of PEP carboxylase in parasitic plants are discussed.