Abstract: In this study,the influences of hydrogen-rich water (HRW) treatment on the dry matter content,relative water content,chlorophyll contents, electrolyte leakage (EL) and antioxidant enzymes activity of Kentucky bluegrass (Poa pratensis) ‘Midnight II’ were examined by spraying 50% HRW on leaves and roots. The results showed that HRW treatment significantly increased water holding capacity of cells and chlorophyll contents of leaves and decreased EL under salt stress. By analyzing reactive oxygen species (ROS) and malondialdehyde contents,antioxidant enzyme activities and antioxidant enzyme gene expression under 0 d,5 d and 20 d of salt stress in Kentucky bluegrass,it was found that under salt stress,especially under long-time of salt stress,ROS contents were decreased,and cell membrane stability increased. Meanwhile,HRW treatment increased the activities of some antioxidant enzymes under long-time of salt stress. In addition,HRW induced down-regulated expression of antioxidant enzyme genes CAT2,APX1 and MR. Research indicates that the changes of ROS content might play a key role in the effects of HRW on salt-tolerance of Kentucky bluegrass. The results had guiding significance for the research of turfgrass salt-tolerance physiology and hydrogen biology in the future.

Key words: Kentucky bluegrass, Hydrogen-rich water, Salt stress, Reactive oxygen species, Antioxidant enzymes

摘要： 本研究以草地早熟禾（Poa pratensis）‘Midnight II’为材料，采用50%的富氢水（Hydrogen-rich water，HRW）叶片喷施及灌根的方法，分析HRW处理对200 mM NaCl胁迫条件下草地早熟禾叶片干物质含量、相对含水量、叶绿素含量、电解率外渗（Electrolyte leakage，EL）及抗氧化酶活性的影响。结果表明：HRW处理显著增加了盐胁迫条件下细胞的持水能力，提高了叶片的叶绿素含量，降低了EL值；通过分析0 d，5 d和20 d盐胁迫条件下草地早熟禾叶片活性氧（Reactive oxygen species，ROS）和丙二醛含量，抗氧化酶活性以及抗氧化酶基因表达发现，在盐胁迫，尤其是长时间盐胁迫条件下，HRW处理显著降低了ROS含量，增加细胞膜稳定性，同时提高了长时间盐胁迫条件下部分抗氧化酶的活性，且诱导了抗氧化酶基因CAT2，APX1，MR的下调表达。研究结果表明，在HRW对草地早熟禾耐盐性的影响中，ROS的含量变化可能发挥关键作用。研究结果对草坪草耐盐生理以及氢气生物学的研究具有一定的指导意义。

关键词: 草地早熟禾, 富氢水, 盐胁迫, 活性氧, 抗氧化酶