Validation of Reference Genes for Grain Filling in White Oats.

White oat (Avena sativa L.) is a well known functional food. Its consumption in human diets has increased due to benefits originating from grain components, such as β-glucans, functional proteins, unsaturated fatty acid lipids, antioxidants and others. Despite its excellent grain chemical constitution, variations are seen among the many oat genotypes available in the market. Gene expression studies can aid to understand important components of the biological processes in the oat grain. Therefore, our group has focused on the study of oat genes related to grain chemical quality using RT-qPCR. However, very little information is available regarding the best reference genes for grain development in oats and the objective of this study is to define the best genes for use in experiments measuring gene expression in this developmental phase.  Seeds from Brazilian cultivars FAPA Louise, URS FAPA Slava, Brisasul, UPFA Gaudéria and IAC 7 were obtained in the experimental field of the Plant Genomics and Breeding Center in 2013, in the Capão do Leão County-RS. The experimental design was random blocks with three replications and the plot area was 3 m², with 0.20 m between rows and density of 250 viable seeds m^-2. RNA was extracted from panicles using the reagent Trizol, treated with DNAse, and for cDNA synthesis the kit SuperScript™III First-Strand System for RT-PCR (InvitrogenTM) was used, according to manufacturer guidelines. Primers for the followiing genes were tested: Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), alpha-tubulin (TUBα) beta-tubulin (TUBβ), elongation factor-1 alpha (ELF1A), 18S ribosomal RNA (18S), and 28S ribosomal RNA (28S).The genes for Glyceraldehyde-3-phosphate dehydrogenase, alpha-tubulin, elongation factor-1 alpha,  and Actin may be used as endogenous controls in studies related to gene expression during the grain filling phase in white oats.