Modern climate changes are exacerbating drought, seriously threatening plants and their productivity. Plants can activate defense mechanisms, including gene regulation, to counteract this stress. The aim of the study was to study the expression of the DREB gene in oak seedlings during drought to identify the molecular mechanisms of plant adaptation to stressful conditions. To evaluate the expression among the F2 families of the progeny of plus-sized oak trees, the following stages were carried out: setting up a greenhouse experiment, collecting biomaterials, isolating RNA, conducting reverse transcription and configuring the hybridization of primers to a cDNA matrix in accordance with the PCR protocol. As a result of our study, an increase in the expression of the DREB2 gene in genotype 139/1 was revealed in drought conditions, which indicates its potential ability to adapt to water scarcity. In genotype 151/1, no increase in DREB2 expression was detected under the same conditions, which emphasizes the role of other genetic factors in its adaptation to stress.