1 Molekylær Genetik og Bioteknologi, Faculty of Agricultural Sciences, Aarhus University, Aarhus University2 Department of Genetics and Biotechnology, 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 University4 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 plant used in feeding monogastric animals. Barley grain provides a high amount of energy sources (starch), vitamins and although low level proteins but in highly digestible form. Unfortunately the amino acid composition of the grain of feed cultivars is not favorable for pigs which are extensively produced in Denmark and the rest of Europe. Hordeins which are the main storage proteins of barley grain, are mostly responsible for unfavorable amino acid composition. Low content or lack of essential amino acids (lysine, cysteine) force the need for supplementation and high content of non-essential amino acids (proline, glutamine) contribute to nitrogen overload and pollution of environment. Hordeins consist of gene families and their proportion in different lines may differ substantially. Six barley cultivars with high protein content (Netto, PR3440, Kontiki, Fairytale, PR3528 and IC364) and Golden Promise as a control had been selected for analysis of hordeins expression during grain development. All the known hordein coding sequences were collected from commonly available databases (NCBI, HarvEST). Subsequently all these sequences were classified into groups and subgroups (B1, B3, C, D and Γ). Real-Time PCR (qRT-PCR) method had been chosen to check the presence and amount of different protein transcripts. Specific primers have been designed with Primique and AlleleID programs and checked with qRT-PCR first on the control cultivar Golden Promise followed by the gene expression analysis of the collected material from the different cultivars during grain development. It was noticed that there are changes in quantity and quality of storage proteins transcripts in consecutive development phases and among different lines. Detailed knowledge about these differences will be a starting point in creating novel cereal cultivars with high protein content and better amino acid composition.