Carex muskingumensis and Osmotic Stress: Identification of Reference Genes for Transcriptional Profiling by RT-qPCR

Reference genes expression stability in Avena sativa L. during compatible and incompatible interactions with Puccinia graminis

A reliable qPCR experiment requires the selection of reference genes with a stable level of expression in a given experimental system. This study attempts to determine the reference genes (RGs) for the A. sativa-P. graminis experimental setup. We evaluated nine candidate reference genes in A. sativa (oat line Pg4 and the cultivar Kasztan) during compatible and incompatible interactions with different pathotypes of Puccinia graminis f. sp. avenae in six time points post-inoculation. The identification of genes with high expression stability was performed by four algorithms (geNorm, NormFinder, BestKeeper and ΔCt method). We found that the most appropriate combination of RGs for RT-qPCR data normalization were HNR (heterogeneous nuclear ribonucleoprotein 27C) + EF1A (elongation factor 1-alpha) + EIF4A (eukaryotic initiation factor 4A-3). The worst candidates for normalization in this dataset were CYP (cyclophilin) and TUA (alpha tubulin). Identified reference genes are suitable candidates for the standardization of gene expression studies in the A. sativa-P. graminis interaction system and potentially other related pathogens. To date, this is the first report of RGs selection in this pathosystem.

Validation of reference genes as an internal control for studying Avena sativa-Puccinia coronata interaction by RT-qPCR

In this study we evaluated eleven candidate reference genes in Avena sativa during compatible and incompatible interactions with two different pathotypes of Puccinia coronata f. sp. avenae in six time points post-inoculation. The identification of genes with high expression stability was performed by four algorithms (geNorm, NormFinder, BestKeeper and ΔCt method). The results obtained confirmed that the combination of two genes would be sufficient for reliable normalization of the expression data. In general, the most stable in the tested plant-pathogen system were HNR (heterogeneous nuclear ribonucleoprotein 27C) and EF1A (elongation factor 1-alpha). ARF (ADP-ribosylation factor) and EIF4A (eukaryotic initiation factor 4A-3) could also be considered as exhibiting high expression stability. CYP (cyclophilin) was shown by all assessment methods to be the worst candidate for normalization in this dataset. To date, this is the first report of reference genes selection in A. sativa–P. coronata interaction system. Identified reference genes enable reliable and comprehensive RT-qPCR analysis of oat gene expression in response to crown rust infection. Understanding the molecular mechanisms involved in the host–pathogen interactions may expand knowledge of durable resistance strategies beneficial to modern oat breeding.