Comparative transcriptome analysis of barley (Hordeum vulgare L.) glossy mutant using RNA-Seq

Waxy cuticle plays an important role in the resistance to various biotic and abiotic stresses. Barley is generally covered with cuticular wax, but glossy mutants are shiny green without wax. The morphological structure of wax was found to be significantly different between the glossy mutant and the wild-type line when examined under a scanning electron microscope. Transcriptomic analysis was performed to identify genes related to waxy cuticle formation. A total of 243 differentially expressed genes (DEGs) were detected. Seven unigenes related to waxy cuticle biosynthesis were confirmed by quantitative real-time PCR. Results were highly consistent with the RNA-Seq results. Differential expressions of WAX2, WSD1, FAR1, and LACS could potentially explain the differences in the cuticular waxes of the two barley lines. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway-enrichment analyses were performed to better understand the functions of these DEGs. This study not only provides valuable information for understanding the molecular mechanisms of the synthesis of cuticular waxes and metabolism, but also establishes the foundations for further genomics research and waxy gene cloning in barley.