Identification and functional analysis of the HvWRKY1 gene associated with Qingke (Hordeum vulgare L. var. nudum Hook. f.) leaf stripe disease

To explore the role of WRKY transcription factors (TFs) in the resistance process of Qingke (Hordeum vulgare L. var. nudum Hook. f.), leaves of the leaf stripe disease-resistant variety Kunlun 14 and the susceptible variety Z1141 were sequenced by transcriptome sequencing (RNA-seq). A differentially expressed gene HvnWKRY1 was identified, and its disease-resistance function was preliminarily analysed. The result showed that the open reading frame (ORF) of the gene was 1 062 bp and encoded 354 amino acids. It contained the conserved WRKY domain (273-351) and belonged to the WRKY protein family. The phylogenetic tree results showed that HvWRKY1 was most closely related to Hordeum vulgare L. The WRKY family of Qingke, barley, maize and rice were divided into categories I, II, and III, among which HvWRKY1 was located in group III. Results of the quantitative real-time fluorescence PCR (qRT-PCR) showed that the expression of HvWRKY1 was significantly (P < 0.01) higher in leaf stripe infected leaves of Kunlun 14 than that of Z1141. In Arabidopsis thaliana transformed with HvWRKY1, resistance to Botrytis cinerea was enhanced. The RNA-seq analysis showed there were 824 differentially expressed genes (DEGs). Data of the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment indicated, that a plant-pathogen interaction pathway was enriched. This study is expected to provide a theoretical basis for further studies of functioning of the Qingke gene HvWRKY1 in resistance to the leaf stripe disease.