In present experiment we evaluated the effects of the utrasonication of winter wheat seeds on seedling growth and development. Effect of treatment on the gene transcription and DNA methylation of seedlings were evaluated. Overall design: In present experiments, the germination of a breeding line of winter wheat (Triticum aestivum L. cv. SE15) was investigated. The water content of the seeds was 13.6%. Half of the seeds (100 seeds) were ultrasonicated before germination at 30 kHz, 70 W for 5 minutes. The seeds were placed into open Petri dishes 4 cm away from the ultrasound head. The parameters of the ultrasound treatment have been optimized previously in preliminary experiments. The other half of the seeds (100 seeds) served as control and were non-ultrasonicated. Thereafter, winter wheat seeds were germinated at 20 °C in darkness for a week, in accordance with the Hungarian standard of MSZ 6354-3:2008 describing the determination of germination. Seedling samples were collected 7 days after germination. Three independent biological samples were collected both from control and from ultrasonicated plant material and they were stored at -80 °C until DNA and RNA analysis.