Analysis of physiological-biochemical indicators that cause the increase in osmo-resistance of genetically modified wheat

Aim. To investigate the physiological and biochemical characteristics of the seed generation (T4) of genetically modified wheat (Triticum aestivum L.) with a double-stranded RNA suppressor of the proline dehydrogenase (pdh) gene under osmotic stress. Methods. Proline dehydrogenase (PDH) activity assay, free L-proline (Pro) content; carbohydrates and protein. Results. The activity of proline dehydrogenase, the content of proline, proteins and carbohydrates under conditions of normal irrigation, water deficit and irrigation restoration were determined. Conclusions. It has been shown that genetically modified plants with partial suppression of pdh demonstrate changes in the complex of physiological and biochemical parameters that contribute to increased osmototoxicity. They are characterized by reduced activity of proline dehydrogenase and increased levels of proline. During dehydration, the level of Pro in T4 plants increased and remained elevated in the first hours after rehydration, which contributed to maintaining carbohydrate balance. The sucrose/monosaccharide ratio in transgenic variants remained stable regardless of cultivation conditions. Analysis of protein content showed that under optimal hydration, its level in T4 plants and the original genotypes did not differ significantly. At the same time, in control plants under water stress conditions, an increase in protein content was observed, which may indicate activation of the synthesis of stress response proteins.