Oxidative Homeostasis in Germinating Pea Seeds (Pisum sativum L.) Depending on Ultrasonic Exposure Duration

The effect of the duration of ultrasound exposure (5, 10 and 20 min) with an intensity of 25 kW/m2 and a frequency of 26.1 kHz on the level of lipid peroxidation, oxidative modification of proteins, activity of cysteine proteinases and expression of the cysteine proteinase gene in germinating pea seeds was studied. It was shown that the intensity in the region of seed localization, that is, directly above the central piezoelectric converter, was distributed fairly evenly, and at the same time had a diffuse character. There was a multidirectional trend of changes in the studied indicators in response to ultrasound exposure. The level of malondialdehyde increased with increasing exposure time. An increased content of oxidized proteins was recorded in germinating pea seeds after 10 min of ultrasound exposure, whereas after 20 min of exposure, a decrease in the level of oxidative modification of proteins was observed. The activity of cysteine proteases was higher in pea seeds after 5 min of ultrasound exposure, and the content of mRNA transcripts increased in all experimental samples.