盐碱胁迫下外源硫化氢对裸燕麦叶片氨基酸代谢过程的影响_刘建新.pdf

第 32 卷第 2 期Vol.32，No.2119-1302023 年 2 月草业学报ACTA PRATACULTURAE SINICA刘建新，刘瑞瑞，刘秀丽，等.盐碱胁迫下外源硫化氢对裸燕麦叶片氨基酸代谢过程的影响.草业学报，2023，32（2）：119130.LIU Jian-xin，LIU Rui-rui，LIU Xiu-li，et al.Effects of exogenous hydrogen sulfide on amino acid metabolism in naked oat leaves under saline-alkalistress.Acta Prataculturae Sinica，2023，32（2）：119130.盐碱胁迫下外源硫化氢对裸燕麦叶片氨基酸代谢过程的影响刘建新*，刘瑞瑞，刘秀丽，欧晓彬，贾海燕，卜婷，李娜（甘肃省陇东生物资源保护利用与生态修复重点实验室，陇东学院生命科学与技术学院，甘肃 庆阳 745000）摘要：信号硫化氢缓解植物盐碱胁迫机理备受关注。为探讨外源硫化氢对盐碱胁迫下植物氨基酸代谢的调控机制，采用盆栽土培试验，以裸燕麦品种 定莜 9号 为材料，设置盆土不添加盐碱和添加 3.00 g kg-1盐碱（摩尔比 NaCl Na2SO4Na2CO3NaHCO3=12819）与抽穗期叶面喷蒸馏水和喷 50 mol L1硫化氢供体硫氢化钠（NaHS）溶液，共 4个处理。研究其对叶片中总氨基酸、丙二醛含量和籽粒产量的影响；运用液相色谱和质谱检测，采用主成分分析 22种组成蛋白质的氨基酸中差异氨基酸，解析外源硫化氢对氨基酸代谢途径的调控效应。结果表明：在裸燕麦叶片中未检出高半胱氨酸。喷施 NaHS 溶液对盐碱胁迫下裸燕麦叶片中总氨基酸含量下降的缓解效应不显著，对盐碱胁迫诱导的丙二醛含量的升高和籽粒产量的下降有显著的缓解作用。主成分分析结果显示：盐碱胁迫下，喷施 NaHS 可显著下调裸燕麦叶片中-酮戊二酸族的鸟氨酸和草酰乙酸族的天冬酰胺含量；显著上调-酮戊二酸族的谷氨酰胺、脯氨酸、精氨酸和丙酮酸族的亮氨酸及芳香族的酪氨酸含量，对甘氨酸、丝氨酸（3-磷酸甘油酸族）、色氨酸、苯丙氨酸（芳香族）、丙氨酸、缬氨酸（丙酮酸族）、-氨基丁酸、组氨酸、谷氨酸（-酮戊二酸族）、异亮氨酸、苏氨酸、甲硫氨酸、赖氨酸、天冬氨酸（草酰乙酸族）含量无显著影响。表明外源硫化氢参与盐碱胁迫下裸燕麦氨基酸代谢途径的调控，它能够缓解盐碱胁迫造成的氧化伤害和同化物积累抑制。关键词：盐碱胁迫；硫化氢；裸燕麦；氨基酸代谢Effects of exogenous hydrogen sulfide on amino acid metabolism in naked oatleaves under saline-alkali stressLIU Jian-xin*，LIU Rui-rui，LIU Xiu-li，OU Xiao-bin，JIA Hai-yan，BU Ting，LI NaGansu Key Laboratory of Protection and Utilization for Biological Resources and Ecological Restoration，College of Life Sciences andTechnology，Longdong University，Qingyang 745000，ChinaAbstract：The mechanism where by hydrogen sulfide alleviates saline-alkali stress in plants has attracted muchattention.This experiment investigated the mechanisms underlying exogenous hydrogen sulfide effects on the aminoacid metabolism of plants under saline-alkali stress in potted plants of the naked oat varietyDingyou 9grown insoil.There were four treatments：a 22 factorial combination of no saline-alkali or 3.00 g kg1saline-alkali（molarratio NaCl Na2SO4Na2CO3NaHCO3=12 8 1 9）added to the soil in the pot，and the leaves were sprayed withdistilled water or 50 mol L1sodium hydrosulfide（a hydrogen sulfide donor，NaHS）solution at the heading stage.Effects of exogenous hydrogen sulfide on the total amino acid and malondialdehyde contents in leaves and on the grainDOI：10.11686/cyxb2022044http：/收稿日期：2022-01-22；改回日期：2022-03-09基金项目：国家自然科学基金（31960375；31860114）和甘肃省自然科学基金（20JR5RA491；20JR5RA486）资助。作者简介：刘建新（1964-），男，甘肃通渭人，本科，教授。E-mail： 通信作者 Corresponding author.E-mail：Vol.32，No.2ACTA PRATACULTURAE SINICA（2023）yield of naked oats under the four treatments were studied.Liquid chromatography and mass spectrometry were usedfor chemical analysis，and data were analyzed by principal component analysis of levels of the 22 amino acids thatmake up the protein，in order to determine the regulatory effect of exogenous hydrogen sulfide on amino acidmetabolic pathways.It was found that：homocysteine was not detected in the leaves of naked oat.There was nosignificant decrease in total amino acid content in naked oat leaves under saline-alkali stress as a result of sprayingNaHS，but NaHS significantly alleviated the increase in malondialdehyde content in leaves and the decrease in grainyield induced by saline-alkali stress.The results of principal component analysis showed that under saline-alkalistress，spraying NaHS solution significantly down-regulated the contents of ornithine（-ketoglutarate family）andasparagine（oxaloacetate family），and significantly up-regulated the contents of glutamine，proline，arginine（-ketoglutarate family），leucine（pyruvate family），and tyrosine（aromatic family）in leaves，but had no significanteffect on the contents of glycine，serine（3-phosphoglycerate family），tryptophan，phenylalanine acid（aromaticfamily），alanine，valine（pyruvate family），4-aminobutyric acid，histidine，glutamic acid（-ketoglutarate family），isoleucine，threonine，methionine，lysine and aspartic acid（oxaloacetic acid family）.The above results indicate thatexogenous hydrogen sulfide is involved in the regulation of amino acid metabolic pathways in naked oat under saline-alkali stress，and that NaHS can alleviate the oxidative damage and inhibition of assimilate accumulation caused bysaline-alkali stress.Key words：saline-alkali stress；hydrogen sulfide；naked oats；amino acid metabolism土壤盐渍化是限制农业发展和威胁生态安全的世界性环境问题1。我国内陆地区的盐碱地主要为盐（NaCl、Na2SO4）碱（NaHCO3、Na2CO3）复合类型2。植物遭受盐碱复合胁迫时在渗透胁迫和营养失衡基础上协同叠加高pH 胁迫，对植物造成的伤害远大于单一盐胁迫或碱胁迫3。目前，有关植物抗盐碱机制的探究多集中在盐胁迫方面，对碱胁迫和盐碱复合胁迫涉及相对较少。盐碱复合胁迫下，植物会重构体内碳氮代谢平衡，使碳代谢向氮代谢偏移，积累更多如脯氨酸、游离氨基酸等含氮有机物来加强渗透调节，以增强盐碱适应能力4-5。研究表明，植物氨基酸代谢积累与其耐盐性密切相关6。盐胁迫下，植物叶片中重要氨基酸显著积累7，参与渗透调节、活性氧清除和离子运输，缓解盐胁迫对叶肉细胞的生理伤害8-9。碱胁迫强烈影响水稻（Oryza sativa）氨基酸的代谢10，且氨基酸代谢的独特调节与小麦（Triticum aestivum）品种对短暂干旱的耐受性增强有关11。目前，有关植物氨基酸代谢对盐碱复合胁迫的响应及外源信号对其响应的调节效应仍尚不清楚。植物气体信号硫化氢（hydrogen sulfide，H2S）参与许多生理过程调控，能够增强植物对非生物胁迫的抗性12。研究表明，盐胁迫下，H2S可抑制紫花苜蓿（Medicago sativa）细胞钾离子外流13；维持水稻矿质离子平衡13和降低大麦（Hordeum vulgare）钠钾比14；提高茶树（Camellia sinensis）15和玉米（Zea mays）16活性氧清除能力。外源 H2S参与盐碱胁迫下植物可溶性蛋白质、游离氨基酸和脯氨酸代谢调控4,17，且随 H2S浓度和处理时间4及植物生育期不同18对可溶性蛋白质、游离氨基酸和脯氨酸代谢存在正负调控。裸燕麦（Avena nuda）是我国北方和西部地区种植的禾本科燕麦属粮饲兼