关键词: 小麦, 重金属, 铅胁迫, 转录组, 差异表达基因

Abstract: In order to explore the molecular mechanism of wheat in response to heavy metal Pb stress,the wheat cultivar AK58 was treated with different concentrations [0 (CK),40,80,160 mg/L] of Pb by hydroponic method, the root transcriptome was sequenced, then the differentially expressed genes were screened and analyzed, and GO classification and KEGG enrichment analysis were done.The results showed that under different concentrations of Pb,the root length and number of wheat were inhibited,and the inhibition effect was stronger with the increase of Pb concentration.A total of 38 904 differentially expressed genes were obtained between Pb stress treatment and CK.Among them,there were 6 072,16 581 and 16 251 differentially expressed genes under 40,80 and 160 mg/L Pb stresses,respectively.The differentially expressed genes of treatment with 80 mg/L Pb were selected as the research focus for GO classification and KEGG pathway enrichment analysis. GO classification showed that up-regulated differentially expressed genes were mainly involved in immune system processes,exercise processes,metabolic processes,rhythmic processes,catalytic activity and electron carrier activity;the down-regulated differentially expressed genes were mainly involved in development,growth,localization,replication,reproduction processes,transport activity and antioxidant enzyme activity.KEGG enrichment analysis found that up-regulated differentially expressed genes were mainly involved in plant hormone signal transduction pathway,plantpathogen interaction pathway,drug metabolism pathway and MAPK signaling pathway;the down-regulated differentially expressed genes were mainly involved in the secondary metabolite biosynthesis pathway,phenylpropane biosynthesis pathway,antibiotic biosynthesis pathway,carbon metabolism and sucrose metabolism.Six differentially expressed genes responding to Pb stress were selected for RT-PCR verification.The results showed that the expression patterns of the six differentially expressed genes were consistent with the results of RNA-Seq analysis,which further verified the accuracy of the RNA-Seq results.

Key words: Wheat, Heavy metal, Pb stress, Transcriptome, Differentially expressed genes