Objective   Key genes involved in the detoxification of pyroxsulam in naked barley were identified to facilitate breeding an herbicide-tolerant variety.

  Method  Leaves of herbicide-sensitive Qing 0160 and herbicide-resistant Qing 0306 naked barley were treated with pyroxsulam for 0, 1, or 6 d prior to a high throughput transcriptome sequencing.

  Result  The GO of the differentially expressed genes were significantly enriched in photosynthesis before as well as after the pyroxsulam treatment. Significant KEGG enrichment of the genes related to antioxidants in the glutathione metabolic pathway and the stress-related genes in the phenylpropanol and pyridine alkaloid biosynthesis pathways was observed 1d after the treatment. And 6 d afterward, the genes related to the biological processes that maintain the cell function as well as the biosynthesis and metabolism of amino acids were significantly enriched. Further analysis indicated that the expressions of SOD21972, POD55052, CAT15170, DHAR59510, APX42784, GR34873, GSTs849, GSTs36979, GSTs31507, GSTs15106, andGSTs20762 were upregulated, while PSⅡ55705, Cc31194, Cc17547, Cc17551, and CYP12424 downregulated. POD55052 in the herbicide-sensitive naked barley was highly expressed but not in the herbicide-resistant counterparts. On the other hand, the expressions of SOD21972, CAT15170, DHAR59510, APX42784, GR34873, GSTs849, GSTs36979, GSTs31507, GSTs15106, GSTs20762, PSⅡ55705, Cc31194, Cc17547, Cc17551, and CYP12424 were higher in the herbicide-resistant than in the herbicide-sensitive naked barley. It suggested that they might be involved in the pyroxsulam-resistance of the plants.

  Conclusion  The basically same trend shown in this study on the gene express by qRT-PCR and the transcriptome sequencing unveiled the genes possibly associated with the pyroxsulam detoxification mechanism of naked barley. The information would facilitate the breeding of an herbicide-resistant variety.