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植物研究 ›› 2011, Vol. 31 ›› Issue (6): 674-679.doi: 10.7525/j.issn.1673-5102.2011.06.006

• 论文 • 上一篇    下一篇

碱胁迫对黑麦草幼苗根系活性氧代谢和渗透溶质积累的影响

刘建新;王鑫;王瑞娟;李东波   

  1. 陇东学院生命科学与技术学院/甘肃省高校陇东生物资源保护与利用省级重点实验室,庆阳 745000
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2011-11-20 发布日期:2011-11-20
  • 基金资助:
     

Effects of Alkaline Stress on the Metabolism of Reactive Oxygen Species and Osmotica Accumulation in Ryegrass Seedling Roots

LIU Jian-Xin;WANG Xin;WANG Rui-Juan;LI Dong-Bo   

  1. College of Life Science and Technology,Longdong University/University Provincial Key Laboratory for Protection and Utilization of Longdong Bio-resources in Gansu Province,Qingyang 745000
  • Received:1900-01-01 Revised:1900-01-01 Online:2011-11-20 Published:2011-11-20
  • Supported by:
     

摘要: 为了探讨牧草对碱胁迫的耐受程度,采用营养液砂培方法,研究了不同浓度NaHCO3(0、50、100、150和200 mmol·L-1)胁迫对黑麦草幼苗根系生长、活性氧代谢和渗透溶质积累的影响。结果表明:NaHCO3胁迫显著抑制黑麦草幼苗根系的生长,其抑制程度随胁迫浓度提高而增强,黑麦草可耐受的最高NaHCO3浓度约为150 mmol·L-1。随着NaHCO3胁迫浓度的增加,黑麦草根中超氧阴离子(O2)、过氧化氢(H2O2)和丙二醛(MDA)含量明显上升,超氧化物歧化酶(SOD)活性和谷胱甘肽(GSH)含量显著下降,过氧化氢酶(CAT)、过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)活性及抗坏血酸(ASA)含量先升后降。黑麦草根中Na+含量随NaHCO3浓度增大而增加,K+含量和K+/Na+比降低,可溶性糖含量先升后降,脯氨酸含量则先降后升,游离氨基酸含量呈先升后降再升高变化。表明碱胁迫导致的活性氧代谢失调和Na+、K+失衡及积累有机溶质进行渗透调节时更多能量的消耗可能是黑麦草根系生长受抑的重要因素。

关键词: 碱胁迫, 黑麦草, 活性氧代谢, 渗透溶质

Abstract: To explore the tolerant extent of ryegrass seedlings to alkaline stress, ryegrass seedlings were exposed to Hoagland’s nutrient solution with NaHCO3 added (0, 50, 100, 150, 200 mmol·L-1), and the effects of NaHCO3 stress on the growth of roots, metabolism of reactive oxygen species (ROS) and osmotica accumulation in roots were studied by a sandy culture in greenhouse. The results showed: Alkaline stress had significantly inhibitory effects on the roots growth of ryegrass seedlings, the inhibition was aggravated with the increasing of NaHCO3 concentration, the maximum concentration for ryegrass in resistance to alkaline stress was 150 mmol·L-1. With increasing NaHCO3 stress, the contents of O2, H2O2 and MDA in the seedling roots increased dramatically, superoxide dismutase (SOD) activity reduced and glutathione (GSH) contents decreased significantly, the activities of catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) as well as ascorbic acid (AsA) content first increased and then decreased. The root Na+ content increased significantly with increasing NaHCO3 concentration, while root K+ content and K+/Na+ ratio were in adverse, soluble sugar content first increased and then decreased, proline content first decreased and then increased, free amino acid content first increased, then decreased and increased again. All the above results indicated that alkaline stress caused the imbalance of ROS metabolism and the disturbance of Na+ and K+ homeostasis in the roots of ryegrass seedlings, and consumed more energy for osmotic adjustment by accumulating organic solutes, which might partly lead to its growth inhibition under alkaline stress.

Key words: alkaline stress, ryegrass, metabolism of reactive oxygen species, osmotica

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