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Leaf rust caused by <i>Puccinia triticina</i> (Pt) is one of the most dangerous diseases causing significant losses in common wheat crops. In adult plants resistant to rust, a horizontal adult plant resistance (APR) type is observed, which protects the plant against multiple pathogen races and is distinguished by greater persistence under production conditions. Crucial pleiotropic slow-rust genes such as <i>Lr34</i>, <i>Lr46</i>, <i>Lr67</i>, and <i>Lr68</i>, in combination with other genes of lesser influence, continue to increase durable resistance to rust diseases. Based on our previous results, we selected four candidate genes for <i>Lr46</i> out of ten candidates and analysed them for expression before and after inoculation by <i>P. triticina</i>. As part of our study, we also investigated the expression patterns of miRNA molecules complementary to <i>Lr34</i> and the candidate genes. The aim of the study was to analyse the expression profiles of candidate genes for the <i>Lr46</i> gene and the <i>Lr34</i> and <i>Lr67</i> genes responsible for the differential leaf-rust resistance of hybrid forms of the F1 generation resulting from crosses between the Glenlea cultivar and cultivars from Polish breeding companies. In addition, the expression of five miRNAs (tae-miR9653b, tae-miR5384-3p, tae-miR9780, tae-miR9775 and tae-miR164), complementary to <i>Lr34</i>, and selected candidate genes were analysed using stem-loop RT-PCR and ddPCR. Biotic stress was induced in adult plants by inoculation with <i>Pt</i> fungal spores, under controlled conditions. Plant material was collected before and 6, 12, 24, and 48 h after inoculation (hpi). Differences in expression patterns of <i>Lr34</i>, <i>Lr67</i>, and candidate genes (for <i>Lr46</i>) were analysed by qRT-PCR and showed that gene expression changed at the analysed time points. Identification of molecular markers coupled to the <i>Lr</i> genes studied was also carried out to confirm the presence of these genes in wheat hybrids. qRT-PCR was used to examine the expression levels of the resistance genes. The highest expression of <i>Lr46/Yr29</i> genes (<i>Lr46-Glu2</i>, <i>Lr46-RLK1</i>, <i>Lr46-RLK2</i>, and <i>Lr46-RLK3</i>) occurred at 12 and 24 hpi, and such expression profiles were obtained for only one candidate gene among the four genes analysed (<i>Lr46-Glu2</i>), indicating that it may be involved in resistance mechanisms of response to <i>Pt</i> infection.