Effect of Phosphonic Acid Ester PAE-6 on Electron Transport in Thylakoid Membranes of Wheat and Broad Bean

Abstract

Phosphonic acid dialkyl esters (PAE) are a group of compounds exhibiting biological activity as herbicides, defoliants, insecticides etc. (1). They are relatively large and non-rigid molecules described by a general formula RP(O)(OR’)₂. For most PAE, molecular shape and structure as well as order parameters are known not only from experimental work but also from theoretical studies (2 – 4). Such data are very useful for the interpretation of molecular arrangement, elastic deformation, domain formation and molecular anisotropy of these compounds. Independently of the mechanism of their action in the cell, PAE have to penetrate through or to be incorporated into the membranes, so that investigations on these compounds are focused on the motional behaviour of PAE in membranes and their influence on model and biological membranes (3). The aim of this study was to investigate the effect of PAE-6, i.e. phosphonic acid ester having substituted C₆H₁₃ for R and C₂H₅ for R’ on electron transport chain activity of thylakoid membranes of wheat and broad bean.