Identification, Isolation and Expression Analysis of Hevein gene Family in Barley (Hordeum vulgar)

Today, antimicrobial peptides are known as a new generation of antibiotics for treatment of microbial diseases in human and animals and protecting plants against different pathogens. Heveins are a group of antimicrobial peptides which are considered as one of the most important groups of antimicrobial peptides due to the very high diversity and expression in different plant organs as well as the effective role in responding to biotic and abiotic stresses. The main purpose of the current study was identifying and isolation of hevein genes in barley and study of characteristics and their expression in different tissues and environmental conditions. To this purpose, all hevein protein sequences were retrieved from NCBI database. The hevein consensus sequence was obtained from alignment of retrieved sequences. After obtaining the consensus sequence, this sequence was aligned against the barley genome using tBLASTn tool. The resulting sequences were analyzed to determine the full-ORF, and to prediction of functional domains, signal peptides, subcellular localization, physicochemical properties, amino acid frequency and antimicrobial activity. The complete coding sequence of hevein genes were amplified by PCR. In this study, thirteen hevein genes, with an average ORF length of 813 bp, were identified, isolated and sequenced in barley. Hevein genes isolated from barley showed a high similarity with plant heveins in terms of gene and protein sequences, as well as structural and functional characteristics. The results showed that barley Heveins such as other plant Heveins have no introns or have only one intron, and the presence of secretory peptide signals, extracellular aggregation, the presence of ChtBD1 functional domains in all of them and Lyz-like functional domains in some of them was confirmed. The results also showed that antimicrobial activity and maximal expression in roots and reproductive organs as well as expression in response to biological and non-biological stresses are other features of these proteins. The findings of the current study increase our understanding of the effect of Hevein genes on plant biological processes such as growth and development, as well as the response to biotic and abiotic stresses.