盐胁迫下外源褪黑素对苜蓿生理特性及细胞超微结构的影响  

Effects of Exogenous Melatonin on the Physiological Characteristics and Cellular Ultrastructure of Alfalfa Under Salt Stress

作　　者：刘沂欣 王鑫尧 隋晓青[1] 李培英[1] 张前兵[2] 徐博[3] LIU Yi-xin;WANG Xin-yao;SUI Xiao-qing;LI Pei-ying;ZHANG Qian-bing;XU Bo(College of Grassland,Xinjiang Agricultural University,Key Laboratory of Grassland Resources and Ecology,Ministry of Education,Western Arid Desert Region,Xinjiang Key Laboratory of Grassland Resources and Ecology,Urumqi,Xinjiang 830052,China;School of Animal Science and Technology,Shihezi University,Shihezi,Xinjiang 832000,China;School of Forestry and Grass Science,Jilin Agricultural University,Changchun,Jilin Province 130118,China)

机构地区：[1]新疆农业大学草业学院/西部干旱荒漠区草地资源与生态教育部重点实验室/新疆草地资源与生态重点实验室,新疆乌鲁木齐830052 [2]石河子大学动物科技学院,新疆石河子832000 [3]吉林农业大学林学与草学学院,吉林长春130118

出　　处：《草地学报》2024年第12期3743-3751,共9页Acta Agrestia Sinica

基　　金：新疆维吾尔自治区重点研发专项(2023B02031);国家牧草产业技术体系(CARS-34)资助。

摘　　要：为探究不同浓度外源褪黑素(Melatonin,MT)对NaCl胁迫下紫花苜蓿生理特性及细胞超微结构的影响,本试验以耐盐品种‘中苜3号’紫花苜蓿(Medicago sativa L.‘Zhongmu No.3’)和敏盐品种‘公农1号’紫花苜蓿(Medicago sativa L.‘Gongnong No.1’)为材料进行水培试验。结果显示,外施不同浓度MT均可有效减轻盐胁迫给苜蓿幼苗带来的一系列生理损伤。其中,150μmol·L^(-1) MT处理可显著增加幼苗体内抗氧化酶活性、渗透调节物质和羟自由基清除效率,同时在此浓度下,可有效降低盐胁迫下丙二醛、相对电导率、过氧化氢含量。进一步研究发现,MT通过维持紫花苜蓿幼苗叶肉细胞膜的完整性,从而减轻盐胁迫对紫花苜蓿叶肉细胞超微结构的盐害。这些结果表明,MT通过在盐胁迫条件下增强抗氧化防御活性来减少细胞膜损伤和活性氧(Reactive oxygen species,ROS)积累。Using the salt tolerant cultivar Medicago sativa L.‘Zhongmu No.3’and the sensitive salt cultivar Medicago sativa L.‘Gongnong No.1’as test materials,theeffects of different concentrations of exogenous MT on the physiological characteristics and cellular ultrastructure of alfalfa under salt stress were explored by hydroponic test.The results showed that the external application of different concentrations of MT effectively reduced the physiological damage caused by salt stress on alfalfa seedlings.Among them,150μmol·L^(-1) MT treatment significantly increased the activity of antioxidant enzymes,osmoregulatory substances and hydroxyl radical clearance efficiency in seedlings,and effectively reduced the content of Malondialdehyde,relative conductivity,hydrogen peroxide under salt stress.Further studies revealed that MT alleviated the salt damage to the ultrastructure of alfalfa mesophyll cells by maintaining the integrity of the mesophyll cell membrane in alfalfa seedlings.This study showed that MT reduced cell membrane damage and reactive oxygen species accumulation by enhancing antioxidant defense activity under salt stress conditions.

关 键 词：紫花苜蓿 褪黑素 生理特性 超微结构 盐胁迫 

分 类 号：S541[农业科学—作物学]