Nokhrina K. Influence of the cold on the dynamics of some components of phosphatidylinositol cycle and main phospholipids on the early stage of plant ontogenesis

The Ph.D. degree thesis is devoted to the investigations of the reaction of phosphatidylinositol phospholipid fraction components cold-sensitive and freeze-resistant plants to the cold shock action, and to the study of phospholipids and fatty acids content during the low temperature adaptation in different organs of etiolated seedlings of maize on the early stages of ontogenesis. It was shown that low temperature acclimation was accompanied by the accumulation of the main groups of phospholipids and increasing the unsaturation of their fatty acids chains in leaves, coleoptiles and mesocotyles. It has been found that short influence (5-20 min.) of low temperature in the adaptation range (+10 C - for maize and +5 C - for wheat) decreased the content of 32P-labelled components of poliphosphatidylinositol phospholipid fraction (PI(4)P and PI(4,5)P2) in 10 min of influence in leaves and coleoptiles of maize seedlings and in 5 min in coleoptiles of wheat seedlings, unlike the content of individual fractions of structural phospholipids, which level did not change during the period of studying time. The possible role of poliphosphatidylinositols in the primary transduction reactions of the low temperature influence with the help of phosphatidylinositol signal system is discussed.