Phospholipase D (PLD) was hrst discovered in planu. It plays an important role in the regulation of cell functions not only in planu, but also in animal systems. It is interesting from the aspect of its dominant position in the signalling transduction processes. It controls the utilization of the membrane phospholipids for specific intentions - products of its catalytic activity are involved in intracellular communication processes. The study of the cell-regulation-system shows tkat PLD is a part of lipid-based signalling via octadecanoid pathway, which leads to the production of jasmonic acid, the basic signalling molecule in planu. PLD-mediated hydrolysis of the membrane phospholipids posed this enzyme finto the level of the transmembrane and cell signalling participant. This area is interesting in the aspect of the production of biologically active compounds in planu. Because the signal-regulated synthesis of some secondary metabolites by the lipid signalling pathway has been already shown (induction of the gene expression coding the biosynthetic enzymes of flavonoids and terpenoids), the area of PLD study is perspective. This article is orientated on plant PLD and gives a basic review of its biochemical and molecular-biologccky properties (enzymology, molecular structure, subcellular localization, isoenzymes) and its physiological functions on the cell level (lipid signalling pathway, phospholipid degradation, phytohormones and cell signalling, growth, development and cell ageing, membrane remodeling).

        Key words: phospholipids - phospholipase D - cell regulation - signal transduction - transphosphatidylation