1 Department of Molecular Biology and Genetics - Afgrødegenetik og Bioteknologi, Department of Molecular Biology and Genetics, Science and Technology, Aarhus University2 Molekylær Genetik og Bioteknologi, Faculty of Agricultural Sciences, Aarhus University, Aarhus University3 Department of Molecular Biology and Genetics - Afgrødegenetik og Bioteknologi, Department of Molecular Biology and Genetics, Science and Technology, Aarhus University
Barley (Hordeum vulgare) is a very important nutrition source for monogastric animals like extensively produced pigs. Barley grain provides a high amount of starch and vitamins but is also characterized by unfavourable amino acid composition what force the need of supplementation before exploiting as a feed. Hordeins, the main storage proteins of barley grain, are mostly responsible for unfavorable amino acid composition. Hordeins consist of gene families and their proportion in different lines may differ substantially. Detailed knowledge about their expression could be a starting point in creating novel cereal cultivars with high protein concentration and better amino acid composition. Six barley cultivars with high protein content (Netto, PR3440, Kontiki, Fairytale, PR3528 and IC364) and Golden Promise as a control were selected for analysis of hordeins expression at four stages of grain development. All the known hordein coding sequences collected from commonly available databases (NCBI, HarvEST) were classified into groups and subgroups (B1, B3, C, D and Γ). Specific primers were designed with Primique and AlleleID softwares and checked with qRT-PCR first on the control cultivar Golden Promise followed by the gene expression analysis of the collected material from the high protein cultivars. According to the standard curve prepared for actin, the concentration of cDNA in all samples was evaluated and amount of individual transcripts was measured. Amino acid profiles and protein content in all samples were analyzed using UPLC method. It was noticed that there are big differences in quantity and quality of storage proteins transcripts in consecutive developmental phases and among selected cultivars. The data about mRNA expression, amino acids and total protein concentrations were plotted and analyzed using two chemometrics methods: PCA and PLS. Obtained models give an impression about correlations present in and among these two phenomena.