PJB-2021-266
Analysis of miRNA expression associated with gene Lr34 responsible for resistance mechanisms to wheat leaf rust
Agnieszka Tomkowiak, Roksana Bobrowska, Michal Kwiatek, Julia Spychala, Jakub Kuczynski, Agata Tyczewska, Przemyslaw Lukasz Kowalczewski, Dorota Weigt and Tomasz Kosiada
Abstract
Diseases caused by pathogenic fungi significantly limit the yield and quality of common wheat. The most dangerous fungal diseases of wheat include leaf rust, stripe rust and powdery mildew. Cultivating resistant wheat varieties is the most effective way to minimize the development of fungal diseases. Genetically determined resistance of the horizontal type (racially non-specific, adult plant resistance genes) is preferred due to its more persistent expression compared to the major (R) genes determining race-specific resistance, which is often overcome by pathogens. Currently, hexaploid wheat resistance gene Lr34/Yr18/Sr57/Pm38 (hereafter referred to as Lr34) is the best characterized gene determining horizontal-type resistance. The aim of this study was to analyze miRNA expression in selected common wheat varieties, showing the presence of resistance gene Lr34 in response to infection with the fungus Puccinia triticina responsible for leaf rust. The reference varieties (Pavon'S', Myna'S', Frontana'S' and Sparrow'S') contained slow rust resistance genes, including Lr34, whereas the control variant HN ROD did not have these genes. The presence of Lr34 in four reference varieties was confirmed using polymerase chain reaction (PCR). Biotic stress in adult plants was induced by inoculating fungal spores under monitored conditions in a growth chamber. Differences in the expression of various microRNAs (miR9653b, miR9657b, miR9773, miR9677b) associated with gene Lr34 were tested using emulsion PCR (ddPCR). Plant material for analysis was collected before inoculation and 6, 12, 24 and 48 hours after inoculation. The results showed an increase in miR9653b expression in varieties carrying gene Lr34 as a result of plant infection with P. triticina. The ddPCR analysis of miR9657b, miR9773 and miR9677b yielded too low a copy number for correct inference. The expression level of miR9653b in a control variety (HN ROD) lacking this resistance gene remained stable. This demonstrated that miR9653b could be involved in plant resistance mechanisms in response to leaf rust
To Cite this article:
Tomkowiak, A., R. Bobrowska, M. Kwiatek, J. Spychala, J. Kuczynski, A. Tyczewska, P.L. Kowalczewski, D. Weigt and T. Kosiada. 2023. Analysis of miRNA expression associated with gene Lr34 responsible for resistance mechanisms to wheat leaf rust. Pak. J. Bot., 55(1): DOI: http://dx.doi.org/10.30848/PJB2023-1(6)
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