Oxidative homeostasis of germinating wheat seeds depending on the ultrasonic effect’s duration

Background. Ultrasound is actively used to influence living organisms, but itsphysiological effect remains not fully understoodIn connection with the ability of ultrasonicwaves to generate reactive oxygen species in an aqueous medium, special attention, fromour point of view, should be paid to oxidative homeostasis and primary proteolysis ofa reserve nutrient in germinating seeds. As the main indicators, attention should be paid tothe proteins’ oxidative modification (POM), since they are the main traps of bioradicals, buttheir turnover in plant tissues remains unexplored. The purpose of the research is to studythe effect of different times of ultrasonic exposure on the level of POM, lipid peroxidation(LPO), cysteine proteinase activity and expression of its gene (CP) in germinatingwheat seeds. Materials and methods. Wheat seeds (Triticum aestivum L.), “Ekada-70” variety,collected in 2018, were used as the object of the study. The seeds were placed in anaqueous medium of an ultrasonic bath “UNITRA – UNIMA” UM – 4. The treatment wascarried out for 5, 10, and 20 minutes; seeds soaked but not sonicated served as a control.At the end, the level of lipid peroxidation was determined in the seeds by the level of malonicdialdehyde (MDA) concentration, OMB registration of 2,4 – denitrophenylhydrazones(2,4 – DNPH), cysteine proteinase activity and gene expression (CP). Results. The experimentsrevealed the dependence of the studied parameters on the time of ultrasonic exposure.An increase in MDA content in germinating wheat seeds was shown after ultrasonicexposure. The content of 2,4 – DNPH had a wave-like dynamics, did not statistically significantlychange in germinating seeds exposed to ultrasound for 5 min, increased in samplesthat were exposed to ultrasound for 10 min, and decreased in seeds treated with ultrasoundfor 20 minutes. The activity of the studied proteinase was higher in the samples after 5 minutesof ultrasonic treatment and lower than the control values in the seeds after 20 minutesof sonication. Gene expression (SR) was higher in germinating seeds subjected to5–10 minutes ultrasonic treatment, followed by a fall below the control. Conclusions.The intensification of LPO processes, the wave-like dynamics of POM and the primaryactivation of proteolysis with subsequent inhibition in germinating wheat seeds after ultrasoundexposure were established; protein homeostasis is more tolerant to the action of ROScompared to lipids.