Mutations in Selected ABA-Related Genes Reduce Level of Susceptibility to the Beet Cyst Nematode .

is a common parasite of many important crops such as beets and (oilseed rape, cabbage or mustard). is 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 in roots. 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 (, , , , , and ) at the early stage of root infection. Our results show that the expression of , (ABA signalling) and (ABA metabolism) genes was upregulated in feeding sites at 4 dpi, whereas the level of expression of and (ABA receptors) genes was decreased. Mutations in , , , or genes led to a decrease of susceptibility verbalised as the number of fully developed females, whereas mutations in or genes 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.