Analysis of miRNA expression associated with the Lr46 gene responsible for APR resistance in wheat (Triticum aestivum L.)

Abstract

Lr46/Yr29/Pm39 ( Lr46 ) is a gene for slow rusting resistance in wheat. The aim of the study was to analyze the miRNA expression in selected common wheat cultivars carrying resistance genes, Lr46 among others (HN Rod, Pavon‘S’, Myna‘S’, Frontana‘S’, and Sparrow’S’) in response to leaf rust infection caused by Puccinia triticina Erikss. In the Pavon ‘S’, Myna ‘S’, Frontana‘S’, and Sparow‘S’ varieties a product with a length of 242 bp has been identified, which is specific to the Xwmc44 marker linked to the brown rust resistance gene Lr46 . In the next step, the differences in the expression of microRNA (miR5085 and miR164) associated with the Lr46 gene, which is responsible for different resistance of selected wheat cultivars to leaf rust, were examined using emulsion PCR (ddPCR). In the experiment, biotic stress was induced in mature plants by infecting them with fungal spores under controlled conditions in a growth chamber. For analysis the plant material was collected before inoculation and 6, 12, 24, and 48 h after inoculation. The experiments also showed that plant infection with Puccinia triticina resulted in an increase in miR164 expression in cultivars carrying the Lr46 gene. The expression of miR164 remained stable in a control cultivar (HN ROD) lacking this gene. This has proved that miR164 can be involved in leaf rust resistance mechanisms.

Phenotyping and Identification of Molecular Markers Associated with Leaf Rust Resistance in the Wheat Germplasm from Kazakhstan, CIMMYT and ICARDA

“…These cultivars showed a high level of resistance at the stage of an adult plant for the entire growing season (ϕ-0). Different responses of cultivars carrying the same resistance genes to P. triticina may be associated with the cumulative effect of genes, the presence of unidentified genes, different expression levels of resistance genes, and other biotic and abiotic factors [87,88]. Future breeding initiatives can take advantage of the findings of this investigation; sources of race-specific and non-race-specific genes can be used for pyramiding with other effective Lr genes.…”

Transcriptional profiling identifies the early responses to Puccinia triticina infection in the adult plant leaf rust resistant wheat variety Toropi

“…In Arabidopsis, NAC TFs involved in plant cell death were found to be regulated by miR-164 (Kim et al, 2009). miR-164 has been associated with the leaf rust APR gene Lr46, levels of this miRNA being higher in wheat lines carrying Lr46 compared with non-Lr46 lines (Tomkowiak et al, 2020). More wheat genes were downregulated than upregulated, especially at the early time points.…”

Diversity of Expression Patterns of Lr34, Lr67, and Candidate Genes towards Lr46 with Analysis of Associated miRNAs in Common Wheat Hybrids in Response to Puccinia triticina Fungus

“…The functions of miR164 have been identified in plant responses to biotic stresses. The main function attributed to miR164 is to regulate transcript levels of relevant genes [ 47 , 48 , 49 ]. This miRNA also targets the selected candidate gene Lr46 - RLK3 .…”