Genome-wide Identification and Expression Analyses of RPP13-like Genes in Barley

Abstract

Plants have evolved a series of mechanisms to resist pathogens infection. The nucleotide-binding site and leucine-rich repeat (NBS-LRR) family contains the largest number of plant disease resistance genes in plants. Recognition of Peronospora Parasitica 13-like (RPP13-like) genes belong to this superfamily and play important roles in the resistance of various plant diseases including the downy mildew caused by Peronospora parasitica. In this study, 21 RPP13-like genes were identified in barley via bioinformatics. These genes all contained CC, NB-ARC and LRR domains. The physical and chemical properties, chromosome locations, gene structures, protein motifs, 3D protein structures, and microarray based expression dynamics of these genes, as well as their phylogenetic relationship with other plant species were analyzed. Non-expression of MLOC_19262.1 was detected without pathogen infection. When barley was inoculated with the powdery mildew pathogenic fungus, the expression of MLOC_ 19262.1 reached a very high level, suggesting that this gene is an important and promising candidate resistance gene for further study. The two RPP13-like genes, MLOC_57007.2 and MLOC_5059.1 may be involved in barley regular or abiotic stress induced physiological metabolism in specific tissues or at specific developmental stages; furthermore, these functions may be associated with specific domains. These findings provided evidence for the functional diversity of plant pathogen resistance genes and will be helpful for the future characterization of the PRR13-like gene subfamily.