过氧化氢参与干旱条件下脱落酸诱导黄瓜不定根形成  

Hydrogen peroxide is involved in abscisic acid-induced adventitious root formation in cucumber under drought stress

作　　者：李雪萍 金鑫 廖伟彪 胡琳莉 LI Xue-ping;JIN Xin;LIAO Wei-biao;HU Lin-li(College of Horticulture,Gansu Agricultural Universit)

机构地区：[1]甘肃农业大学园艺学院,甘肃兰州730070

出　　处：《干旱地区农业研究》2018年第3期194-201,共8页Agricultural Research in the Arid Areas

基　　金：国家自然科学基金项目(31160398;31560563);中国博士后科学基金项目(20100470887;2012T50828);教育部科学技术研究重点项目(211182);教育部高校博士点新教师基金(201162020005);甘肃省自然科学基金项目(1308RJZA179;1606RJZA073)

摘　　要：以黄瓜(Cucumis sativus.L)为试材,采用聚乙二醇(PEG)模拟干旱胁迫,研究过氧化氢(H_2O_2)与脱落酸(ABA)在干旱胁迫下对黄瓜不定根发生的作用及其相互关系。结果表明:0.3%PEG产生了中度干旱胁迫。干旱条件下外源H_2O_2和ABA可以显著促进黄瓜外植体不定根的发生,且呈明显的剂量效应,800μmol·L^(-1)H_2O_2和0.5μmol·L^(-1)ABA促进效果最显著。干旱胁迫下H_2O_2和ABA共同处理的根数较H_2O_2或ABA单独处理分别高19.3%和31.3%。干旱胁迫下ABA与内源H_2O_2清除剂过氧化氢酶(CAT)或内源H_2O_2合成抑制剂二苯基碘(DPI)共处理较ABA单独处理,根数分别降低15.2%和30.9%,根长分别降低24.1%和26%。进一步结果表明,与PEG处理相比,PEG+ABA处理的叶片气孔开度百分比、密度和相对电导率分别降低了24.2%、15.4%和14.2%,而相对含水量增加了25%。此外,PEG+ABA处理增加了外植体的渗透调节物质(脯氨酸、可溶性糖和可溶性蛋白)含量和过氧化物酶、多酚氧化酶和吲哚乙酸氧化酶的活性,降低了丙二醛含量。然而,内源H_2O_2清除剂CAT逆转了ABA的上述作用。可见,H_2O_2通过调节水分平衡、细胞膜稳定性、渗透调节物质含量和生根相关酶活性参与干旱条件下ABA促进不定根的发生。Cucumber（ Cucumis sativus. L） was used as a test material and we used polyethylene glycol to simulate drought stress to cucumber. The effect of H_2O_2 and ABA on adventitious root development of cucumber（ Cucumis sativus. L） under drought stress and their interrelationship were studied. The results indicated that 0.3% PEG could simulate moderate drought stress. Exogenous H_2O_2 and ABA had significant positive effect on adventitious root development of cucumber explants under drought stress and the effect was dose-dependent with a maximal biological response at 800 μmol·L^（-1） H_2O_2 and 0.5 μmol·L^（-1） ABA treatment. The root number developed in H_2O_2＋ ABA treatment was 19.3% and 31.3% higher than that in H_2O_2 or ABA single treatment,respectively. Compared with ABA single treatment,the root numbers in ABA ＋ H_2O_2 scavenger（ CAT） or ABA ＋ H_2O_2 inhibitor（ DPI） treatment decreased by 15.2% and 30.9%,respectively under drought stress. The root length decreased by 24.1% and26%,respectively. The results showed that PEG ＋ ABA treatment has decreased stomatal aperture,density and relative electric conductivity by 24.2%,15.4% and 14.2% compared to the PEG treatment; while it has increased the relative water content by 25%. Moreover,PEG ＋ ABA treatment has increased the content of osmotic adjustment substances（ praline,water soluble carbohydrate and soluble protein） and the activity of the peroxidase,polyphenol oxidase and indoleacetate oxidase,while has decreased the content of malondialdehyde. However,CAT treatment significantly reversed the promoting function of ABA in adventitious root formation under drought stress. Therefore,endogenous H_2O_2 might be regulating water balance,cell membrane stability,osmotic adjustment substances and relative enzyme activity,involving in the signaling pathway of ABA-induced adventitious rooting under drought stress.

关 键 词：干旱胁迫 黄瓜不定根 脱落酸(ABA) 过氧化氢(H2O2) 水分平衡 细胞膜稳定性 渗透调节物质 

分 类 号：S482.8[农业科学—农药学]