ABSTRACT
Hulless barley (Hordeum vulgar L. var. nudum) is one of the staple foods for Tibetans and an important livestock feed in the Tibetan Plateau. We report the complete mitochondrial genome of Tibetan hulless barely. The complete mitochondrial genome size is 416,675 bp. Hulless barely mitochondrial genome encode 34 protein-coding genes, 19 tRNA genes and three rRNA genes. The mitochondrial genome has 50 forward and palindrome repeats totally. Nucleotide sequence of coding region takes over 13.60%, GC content is 44.33%. The maximum-likelihood (ML) phylogenetic tree based on 11 protein-coding genes common to seven plant mitochondrial genomes using Arabidopsis thaliana as out-group support that hulless barely is close to Triticum species.
ABSTRACT
Hulless barley is an important cereal crop worldwide, especially in Tibet of China. However, this crop is usually susceptible to powdery mildew caused by Blumeria graminis f. sp. hordei. In this study, we aimed to understand the functions and pathways of genes involved in the disease resistance by transcriptome sequencing of a Tibetan barley landrace with high resistance to powdery mildew. A total of 831 significant differentially expressed genes were found in the infected seedlings, covering 19 functions. Either "cell," "cell part," and "extracellular region" in the cellular component category or "binding" and "catalytic" in the category of molecular function as well as "metabolic process" and "cellular process" in the biological process category together demonstrated that these functions may be involved in the resistance to powdery mildew of the hulless barley. In addition, 330 KEGG pathways were found using BLASTx with an E-value cut-off of <10(-5). Among them, three pathways, namely, "photosynthesis," "plant-pathogen interaction," and "photosynthesis-antenna proteins" had significant matches in the database. Significant expressions of the three pathways were detected at 24 h, 48 h, and 96 h after infection, respectively. These results indicated a complex process of barley response to powdery mildew infection.
