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 which forces the need of supplementation before exploiting as a feed. Hordeins, the main storage proteins of barley grain, have a less optimal amino acid profile characterized by a low content or lack of essential amino acids (lysine, cysteine) and a high content of non-essential amino acids (proline, glutamine). Hordeins consist of gene families and their proportion in different cultivars 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 a 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 were collected from commonly available databases (NCBI, HarvEST, TIGR) and classified into groups and subgroups (B1, B3, C, D and Γ). Specific primers were designed with Primique and AlleleID software and checked with qRT-PCR first on the 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 the amount of individual transcripts was measured. Amino acid profiles and protein content in all samples were analyzed using ultra-performance liquid chromatography. It was noticed that there are big changes in quantity and quality of storage protein transcripts in consecutive developmental phases and among different cultivars. The amount of mRNA was compared with amino acid profiles and protein concentrations to obtain correlation among these phenomena.
24th Njf Congress, 2nd Nordic Feed Science Conference: Food, Feed, Fuel and Fun; Nordic Light on Future Land Use and Rural Development; Book of Abstracts, 2011