欢迎访问《草业学报》官方网站,今天是 分享到:

草业学报 ›› 2018, Vol. 27 ›› Issue (2): 48-56.DOI: 10.11686/cyxb2017308

• 研究论文 • 上一篇    下一篇

葡萄糖-6-磷酸脱氢酶在紫花苜蓿干旱耐受性中的响应

熊丽丽1, 闫霜1, 李萍2, *, 杨国柱1, 尹卫1, 严晓霞1, 张韩1   

  1. 1.青海大学生态环境工程学院,青海 西宁810016;
    2.青海大学省部共建三江源生态与高原农牧业国家重点实验室,青海 西宁 810016
  • 收稿日期:2017-07-18 修回日期:2017-10-18 出版日期:2018-02-20 发布日期:2018-02-20
  • 通讯作者: liping051126@163.com
  • 作者简介:熊丽丽(1993-),女,青海乐都人,在读硕士。E-mail: 843293453@qq.com
  • 基金资助:
    国家自然基金地区基金项目(31660063),青海省科技厅基础研究计划(2016-ZJ-930Q),青海大学省部共建三江源生态与高原农牧业国家重点实验室开放课题(2017-KF-05)和青海大学生态环境工程学院中青年科研基金项目(2016-T-4)资助

Role of glucose-6-phosphate dehydrogenase in the drought tolerance of alfalfa

XIONG Li-li1, YAN Shuang1, LI Ping2, *, YANG Guo-zhu1, YIN Wei1, YAN Xiao-xia1, ZHANG Han1   

  1. 1.College of Eco-Environmental Engineering, Qinghai University, Xining 810016, China;
    2.State Key Laboratory of Plateau Ecology and Agriculture, Qinhai University, Xining 810016, China
  • Received:2017-07-18 Revised:2017-10-18 Online:2018-02-20 Published:2018-02-20

摘要: 葡萄糖-6-磷酸脱氢酶(glucose-6-phosphate dehydrogenase,G6PDH,EC1.1.1.49)是磷酸戊糖途径的关键限速酶,参与NADPH和磷酸核糖的合成,在植物响应生物胁迫和非生物胁迫方面有重要作用。研究了葡萄糖-6-磷酸脱氢酶(G6PDH)在紫花苜蓿中对干旱胁迫的响应。首先采用不同浓度的PEG模拟干旱胁迫处理紫花苜蓿幼苗,通过测定不同PEG浓度下紫花苜蓿幼苗的株高、根长、干重、过氧化氢(H2O2)、丙二醛(MDA)含量的变化筛选胁迫浓度来确定干旱胁迫的条件。其次,检测胁迫浓度下紫花苜蓿幼苗中G6PDH的活性变化。第三,通过添加G6PDH的抑制剂Na3PO4,观察干旱胁迫下紫花苜蓿幼苗的生长情况并测定MDA、H2O2含量以及G6PDH活性的变化。最后,综合分析G6PDH对干旱胁迫的响应。结果显示,不同浓度PEG处理下,紫花苜蓿幼苗的生长受到限制,例如株高、根长、鲜重、干重都随PEG浓度的增加而逐渐减小,MDA和H2O2的含量随PEG浓度的增加而增加,其中以15% PEG处理的影响最大;同时,也发现随PEG浓度的增加紫花苜蓿幼苗中G6PDH的活性也较对照增加,15%PEG处理时达最高值;故15%的PEG处理为干旱胁迫模拟最佳条件。通过添加G6PDH的抑制剂Na3PO4后发现,干旱胁迫下紫花苜蓿幼苗的生长明显地受到抑制,其叶片中MDA、H2O2含量分别较干旱胁迫下的增长28.4%、19.9%,G6PDH的活性也明显降低了49.4%。以上结果初步说明G6PDH可能参与调节了干旱胁迫引起的氧化胁迫。

Abstract: Glucose-6-phosphate dehydrogenase (G6PDH, EC1.1.1.49) is the first and critical rate-limiting enzyme in the pentose phosphate pathway. It is involved in the synthesis of NADPH and ribose-5-phosphate, and plays an important role in plant responses to biotic and abiotic stresses. The aim of this study was to explore the role of G6PDH under drought stress in alfalfa. First, 7-day-old alfalfa seedlings were treated with different concentrations of polyethylene glycol (PEG), and then plant height and root length, fresh weight and dry weight, and the contents of hydrogen peroxide (H2O2) and malondialdehyde (MDA) were determined. These analyses were used to define the concentration of PEG causing drought stress to the seedlings. Then, the activity of G6PDH in alfalfa seedlings was determined under a range of stress-inducing PEG concentrations. The G6PDH inhibitor Na3PO4 was applied to alfalfa seedlings under drought stress, and changes in the indexes described above were determined. The results showed that PEG treatment significantly inhibited the growth of alfalfa seedlings. Plant height, root length, fresh weight, and dry weight decreased with increasing PEG concentrations. Compared with non-stressed seedlings, those subjected to PEG-induced drought stress (15% PEG) showed 28.4% and 19.9% higher contents of H2O2 and MDA, respectively, and 49.4% lower G6PDH activity. Application of Na3PO4 decreased the activity of G6PDH and caused the symptoms of drought stress to become more severe, suggesting that G6PDH is involved in the regulation of oxidative stress induced by PEG.