Fatty acid composition of mitochondrial membranes of pea germs exposed to insufficient watering and treated with organophosphorous plant growth regulator

Abstract

The influence of insufficient watering and a melamine salt of bis(oxymethyl)-phosphonic acid (melaphen) on fatty acid composition of mitochondrial membrane of pea seedlings has been studied. It is shown that insufficient watering results in a 1.57-fold decrease in the ratio of unsaturated to saturated C18 fatty acids and in a 3.04-fold decrease in the ratio of unsaturated to saturated C20 fatty acids. The modification of fatty acid composition of mitochondrial membranes was associated with the alterations in their functional state: maximal rates of oxidation of NAD-dependent substrates and the rates of electron transport at the end of respiratory chain decreased. A preliminary treatment of the seeds with 3 × 10−9 M melaphen restored the maximal rates of oxidation of NAD-dependent substrates to the control values. We suggest that the alterations of the electron transport rates in respiratory chain in mitochondria are related to the physicochemical state of the membranes of these organelles, as the treatment with melaphen prevented the changes in fatty acid composition of the membranes of seedlings growing under the conditions of insufficient watering.