Osmotolerance of т4 generation monocotyledonous and dicotyledonous plants with suppressed expression of proline catabolism gene

Abstract

Analysis of transgene function retention in seed generation (Т4) of genetically modified plants of maize, wheat and sunflower was carried out. It was shown that about 80–85 % of seeds of plants created by the biotechnological method had the ability to germinate under conditions of water deficiency and salinization, while in plants of the original forms this index was 20—28 %. Variability in transgene expression among individual variants of the seed generation of genetically modified forms was noted. Almost 65 % of Т4 seedlings of corn and wheat withstood the conditions of super hard osmotic stress created by adding 0,8 M manite to the culture medium, which was lethal to the original forms. Progenies of transgenic plants were also characterized by an increased level of resistance to drought created by the water cessation, which was manifested in the indices of growth processes. At the stage of restoration after the action of prolonged dehydration, the biotechnological plants of sunflower were 17 cm higher than the original form and had 1.5 times larger biomass. Maintaining the viability of genetically modified plants under hard stressful conditions was associated with an increase in the level of free L-proline (Pro). Genetically modified plants had 1.5—2 times higher Pro content compared to the original form both under normal moisture supply and under its deficiency, which may result from partial suppression of the proline dehydrogenase (PDH, pdh) gene. It was found that under normal growth conditions, the activity of the PDH enzyme in transgenic Т4 maize and sunflower seedlings was almost 3 times lower than in the original forms, while for wheat, this difference was 1.6 times. The tendency to lower relatively to control PDH activity in the Т4 generation of the studied representatives of transgenic monocotyledonous and dicotyledonous plants was observed at all stages of growth.