Heterodera schachtiiis a common parasite of many important crops such as beets andBrassicaceae(oilseed rape, cabbage or mustard).Arabidopsis thalianais a model plant also used for studying defence responses to pathogens or pest infections. Defence responses of plants are often regulated and fine-tuned by stress phytohormones: salicylic acid (SA), jasmonic acid (JA), ethylene (Et) and abscisic acid (ABA), of which the role of ABA in these responses is the least examined. The aim of this study was to show, if and which genes related to ABA turnover can be modulated during the development of nematode-induced feeding sites inA. thalianaroots. To answer the question, we performed infection tests on wild type and ABA mutant roots and analysed the expression levels of selected ABA-related genes (ABI1,ABI2,ABI5,PYL5,PYL6,CYP707A1andCYP707A4) at the early stage of root infection. Our results show that the expression ofABI2,ABI5(ABA signalling) andCYP707A4(ABA metabolism) genes was upregulated in feeding sites at 4 dpi, whereas the level of expression ofPYL5andPYL6(ABA receptors) genes was decreased. Mutations inABI1,ABI2,ABI5,CYP707A1orCYP707A4genes led to a decrease ofA. thalianasusceptibility verbalised as the number of fully developed females, whereas mutations inPYL5orPYL6genes did not influence the number of females of the nematode. Based on the results, it can be concluded that the modifications of analysed ABA-related gene expression are required for the proper development of nematodes; however, further in-depth analyses are required.