外源H2S对盐碱胁迫下裸燕麦幼苗叶片渗透胁迫的调节作用  

Regulation of exogenous hydrogen sulfide on osmotic stress in leaves of naked oat seedlings under saline-alkali mixed stress

作　　者：刘建新[1] 刘瑞瑞[1] 贾海燕[1] 卜婷[1] 李娜[1] LIU Jian-xin;LIU Rui-rui;JIA Hai-yan;BU Ting;LI Na(University Provincial Key Laboratory for Protection and Utilization of Longdong Bio-resources in Gansu Province,College of Life Sciences and Technology,Longdong University,Qingyang 745000,Gansu,China)

机构地区：[1]甘肃省高校陇东生物资源保护与利用省级重点实验室,陇东学院生命科学与技术学院,甘肃庆阳745000

出　　处：《生态学杂志》2020年第12期3989-3997,共9页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(31960375)资助。

摘　　要：硫化氢(H2S)作为气体信号在植物抵抗盐碱胁迫中扮演着重要角色。为探讨H2S对盐碱胁迫下植物渗透胁迫的调节作用,以裸燕麦幼苗为材料,采用根部浇灌盐碱混合溶液(NaCl∶Na2SO4∶NaHCO3∶Na2CO3=12∶8∶9∶1)的同时叶面喷施H2S供体NaHS的方法,研究了H2S对盐碱混合胁迫下幼苗叶片细胞膜透性和渗透调节物质的影响。结果表明:在25、50和75 mmol·L^-1盐碱混合胁迫下,随着胁迫时间延长,裸燕麦幼苗叶片中膜脂过氧化产物丙二醛(MDA)含量和细胞膜相对透性增大;喷施10、25和50μmol·L-1NaHS均可使50 mmol·L^-1盐碱混合胁迫引起的裸燕麦叶片MDA含量和细胞膜相对透性增幅显著下降,其中25μmol·L-1NaHS的作用最明显;用25μmol·L-1NaHS喷施可降低50mmol·L^-1盐碱混合胁迫下裸燕麦叶片Na^+含量升高和K^+含量下降的幅度并提高K^+/Na^+;促进裸燕麦幼苗叶片在盐碱胁迫前期(12~48 h)可溶性糖和胁迫后期(60~72 h)可溶性蛋白质及整个胁迫期间(12~72 h)甜菜碱的积累;而对游离氨基酸、脯氨酸和有机酸含量总体上无明显改变或降低趋势。表明外源H2S可通过提高叶片K^+/Na^+和渗透调节物质可溶性糖、可溶性蛋白质和甜菜碱的积累来缓解盐碱胁迫诱导的氧化伤害,从而增强裸燕麦对盐碱胁迫的耐性。Hydrogen sulfide(H2S),as a gas signal,plays an important role in plant resistance to saline-alkali stress.We explored the regulation of H2S on osmotic stress of naked oat(Avena nuda)seedlings under saline-alkali stress.The leaves of seedlings were sprayed with H2S donor NaHS and the roots were irrigated with saline-alkali mixture solution(NaCl∶Na2SO4∶NaHCO3∶Na2CO3=12∶8∶9∶1).The effects of H2S on cell membrane permeability and osmoticum in leaves under saline-alkali mixed stress were investigated.The results showed that the contents of malondialdehyde(MDA),a membrane lipid peroxidation product,and the relative permeability of cell membrane increased with a stressed duration-and concentration-dependent manner under 25,50,and 75 mmol·L^-1 saline-alkali mixed stress.The MDA content and relative permeability of cell membrane under 50 mmol·L-1 mixed saline-alkali stress significantly decreased when sprayed with 10,25 and 50μmol·L-1 NaHS,with the strongest effect under 25μmol·L-1 NaHS.Spraying 25μmol·L-1 NaHS could reduce the increase of Na^+content and the decrease of K^+content in naked oat leaves under 50 mmol·L^-1 saline-alkali mixed stress,and increased K^+/Na^+.Furthermore,it significantly promoted the accumulation of soluble sugar in early salinealkali stress(12-48 h),soluble protein in late saline-alkali stress(60-72 h),and betaine in the whole stress period(12-72 h).However,the contents of free amino acids,proline and organic acids showed no change or decrease trend.Our results indicated that exogenous H2S can alleviate oxidative damage induced by saline-alkali stress through increasing K^+/Na^+ratio and promoting the accumulation of osmotic substances in leaves(soluble sugar,soluble protein and betaine),thus enhance the tolerance of naked oats to salt-alkali stress.

关 键 词：硫化氢 裸燕麦 盐碱混合胁迫 渗透调节物质 

分 类 号：S512.6[农业科学—作物学]