外源NO对盐胁迫下紫花苜蓿生长及膜脂过氧化的影响  

Effects of exogenous nitric oxide on the growth and membrane lipid peroxidation of Medicago sativa under salt stress

作　　者：蒋文博 陈钊 曹新龙 牛军鹏 郭志鹏 崔健[2] 王佺珍[1] JIANG Wenbo;CHEN Zhao;CAO Xinlong;NIU Junpeng;GUO Zhipeng;CUI Jian;WANG Quanzhen(College of Grassland Agriculture, Northwest A&F University, Yangling 712100, Shaanxi, China;College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China)

机构地区：[1]西北农林科技大学草业与草原学院,陕西杨凌712100 [2]西北农林科技大学生命科学学院,陕西杨凌712100

出　　处：《草业科学》2019年第10期2580-2593,共14页Pratacultural Science

基　　金：国家重点研发计划(2017YFE0111000);国家自然科学基金(31472138)

摘　　要：采用0.05、0.1、0.2和0.3mmol·L–1的硝普钠(SNP)为NO供体,研究外源NO对3种不同浓度(24、72、120mmol·L–1)盐胁迫下紫花苜蓿(Medicagosativa)生长的影响。结果表明,在盐胁迫下,紫花苜蓿鲜重、干重和叶绿素含量降低,相对电导率、丙二醛(MDA)、过氧化氢(H2O2)和过氧化物酶(POD)活性显著升高,叶片中抗坏血酸(AsA)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性受到显著抑制(P<0.05),呈现出毒害效应;与对照相比,SNP处理显著(P<0.05)提高了盐胁迫下紫花苜蓿的鲜重、干重、叶绿素、叶绿素a/b和AsA含量,并增强了SOD、CAT和POD的活性,降低了相对电导率、MDA和H2O2的含量,说明SNP可通过增强抗氧化酶活性提高幼苗对活性氧的清除能力,降低膜脂过氧化作用,从而提高紫花苜蓿对盐胁迫的抗性。本研究中24、72和120mmol·L–1盐胁迫对应的最适SNP浓度分别为0.1、0.3和0.3mmol·L–1。Sodium nitroprusside (SNP) agent (0.05, 0.1, 0.2, and 0.3 mmol·L–1) was used as an exogenous nitric oxide source to study the effects of exogenous NO on the growth of alfalfa (Medicago sativa) seedlings under three different salt stress conditions (24, 72, and 120 mmol·L–1). The results showed that the fresh weight, dry weight, and chlorophyll contents of alfalfa decreased. Whereas, the relative electrical conductivity, malondialdehyde (MDA), hydrogen peroxide (H2O2) content, and peroxidase (POD) activity had a remarkable increase (P < 0.05). Additionally, the ascorbic acid (AsA), superoxide dismutase (SOD), and catalase (CAT) activities were significantly inhibited (P < 0.05) under the salt stress, indicating the toxic effects of salt stress on alfalfa. SNP treatments significantly (P < 0.05) improved the fresh weight, dry weight, chlorophyll, chlorophyll a/b, and AsA content and enhanced the SOD, CAT, and POD activities, but decreased the relative electrical conductivity, MDA, and H2O2 contents. This suggests that exogenous NO can enhance antioxidant enzyme activities and decrease lipid peroxidation, thereby improving the resistance of alfalfa to salt stress. The optimum SNP concentration of alfalfa under 24, 72, and 120 mmol·L–1 salt stress was 0.1, 0.3, and 0.3 mmol·L–1, respectively.

关 键 词：紫花苜蓿 盐胁迫 外源一氧化氮 生理特性 

分 类 号：S541.9[农业科学—作物学]