Abstract: Previous studies showed that spraying ethephon could increase the drought resistance of Poa pratensis by increasing the antioxidant enzyme activity. However, the regulation mechanism at the gene level was still unclear. The study was conducted to investigate differential antioxidant enzyme gene expression patterns under drought in Poa pratensis leaves. IlluminaHiseq 2000 sequencing technology was used to analyze the transcriptome. The sequencing data were subsequently analyzed to screen out the antioxidant enzyme genes and to reveal the differences in antioxidant enzyme genes expression under different treatments. The results showed that the antioxidant enzyme genes expression in each subcellular compartment of P. pratensis was different under water stress. Spraying ethephon treatment significantly changed the expression levels of 11 genes under drought. The expression levels of Chl Cu-Zn SOD2, Chl SOD copper chaperone1, Chl MR3, Cyt APX2 and Nuc MR were significantly increased. The expression of Chl GPX2, CytCAT3, Cyt GPX1, Per CAT isozyme, Cu-Zn SOD1 and MR2 was significantly reduced. Under drought stress, the subcellular compartment with the largest number of genes responding to ethephon regulation was chloroplast, following by cytoplasm. The study aimed to provide a theoretical basis for explaining the mechanism of ethephon improving plant drought resistance from the perspective of antioxidant enzymes.

Key words: Poa pratensis, Ethephon, Antioxidant enzyme, Differential gene expression

摘要： 为探究喷施乙烯利提高植物抗氧化酶活性进而提高植物抗旱性在基因层面的调控、作用机制，以草地早熟禾（Poa pratensis）为试验材料，以前期获得的草地早熟禾高通量转录组测序数据为研究对象，分析并筛选出抗氧化酶编码基因，研究不同处理下抗氧化酶编码基因表达量的差异情况，从基因水平探讨乙烯利对干旱胁迫下抗氧化酶编码基因响应乙烯利调控的表达模式。结果表明，干旱胁迫下各亚细胞区室响应乙烯利处理的抗氧化酶编码基因数量和表达情况均不同；喷施乙烯利处理，显著改变了干旱胁迫下11个基因的表达量，Chl Cu-Zn SOD2，Chl SOD copper chaperone1，Chl MR3，Cyt APX2，Nuc MR的表达量显著提高，Chl GPX2，Cyt CAT3，Cyt GPX1，Per CAT isozyme，Cu-Zn SOD1，MR2表达量显著降低；干旱胁迫下，响应乙烯利调控基因数目最多的亚细胞区室依次为叶绿体、细胞质。本结果为研究乙烯利提高植物抗旱性机制提供理论依据。

关键词: 草地早熟禾, 乙烯利, 抗氧化酶, 基因差异表达