外源H_2S对盐碱胁迫下裸燕麦幼苗生长和生理特性的影响  

Effects of Exogenous Hydrogen Sulfide on Growth and Physiological Characteristics 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 Jianxin;LIU Ruirui;JIA Haiyan;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,Gansu 745000,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：《麦类作物学报》2021年第2期245-253,共9页Journal of Triticeae Crops

基　　金：国家自然科学基金项目(31960375)。

摘　　要：为探讨外源H2S缓解植物盐碱胁迫伤害的生理机制及适宜喷施浓度,以裸燕麦为材料,采用盆栽砂培方法,在根部浇灌50 mmol·L-1盐碱混合溶液(NaCl︰Na2SO4︰NaHCO3︰Na2CO3=12︰8︰9︰1),同时叶面喷施不同浓度H2S供体NaHS(0、25、50、100、200、400μmol·L-1),分析了盐碱胁迫条件下外源H2S对幼苗生长及叶片内源H2S和光合色素含量、活性氧代谢和渗透物质积累的影响。结果表明,盐碱胁迫下裸燕麦幼苗叶片L-半胱氨酸脱巯基酶活性和H2S含量均随NaHS喷施浓度的增大而显著提高;喷施25~100μmol·L-1 NaHS能够缓解盐碱胁迫对裸燕麦幼苗生长的抑制,喷施200~400μmol·L-1 NaHS时幼苗生长受抑加重。喷施25~400μmol·L-1 NaHS均不同程度提高了盐碱胁迫下裸燕麦叶片叶绿素、类胡萝卜素和谷胱甘肽含量,对抗坏血酸和可溶性蛋白质含量影响不大,使超氧阴离子、过氧化氢、丙二醛含量和质膜相对透性显著降低或变化不显著;25~200μmol·L-1 NaHS处理下超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性均不同程度提高,过氧化物酶(POD)活性和游离氨基酸含量显著下降或变化不显著,400μmol·L-1 NaHS处理降低了SOD、CAT、APX和POD活性及游离氨基酸、脯氨酸含量;25μmol·L-1 NaHS处理显著降低了可溶性糖含量,50~400μmol·L-1 NaHS处理的可溶性糖含量不同程度提高。隶属函数综合评价显示,喷施25~200μmol·L-1 NaHS提高了盐碱混合胁迫下裸燕麦幼苗的综合评价值(D),400μmol·L-1 NaHS处理的D值显著下降。综合以上结果,喷施适宜浓度NaHS(25~100μmol·L-1)可通过调节活性氧代谢和渗透溶质脯氨酸和可溶性糖积累缓解盐碱胁迫造成的氧化伤害和生长抑制,从而增强裸燕麦对盐碱胁迫的耐性。In order to explore the physiological mechanism of exogenous H2S relieving plant saline-alkali stress injury and the appropriate application concentration,seedlings of naked oat(Avena nuda)cultured with potted sand in a solar greenhouse were irrigated with 50 mmol·L-1 saline-alkali mixed solution(NaCl∶Na2SO4∶NaHCO3∶Na2CO3=12︰8︰9︰1),and the leaves were sprayed with different H2S concentrations(0,25,50,100,200 and 400μmol·L-1 NaHS,a exogenous H2S donor).The seedling growth,endogenous H2S and photosynthetic pigment contents,reactive oxygen species metabolism and osmoticum accumulation in leaves were measured.The results showed that spraying NaHS increased L-cysteine dethioylase(LCD)activity and H2S content in leaves of naked oat seedling under saline-alkali stress,and the LCD activity and H2S content increased with the increase of NaHS concentration.Application of 25-100μmol·L-1 NaHS alleviated the inhibition of saline-alkaline stress on the growth of naked oat seedlings,and NaHS of 200-400μmol·L-1 aggravated the inhibition of saline-alkali stress on the growth of naked oat seedlings.In addition,the contents of chlorophyll,carotenoid and glutathione in naked oat leaves under saline-alkali stress were increased by spraying 25-400μmol·L-1 NaHS to different degrees,but the contents of ascorbic acid and soluble protein did not significantly change,and the contents of superoxide anion,hydrogen peroxide,malondialdehyde and plasma membrane relative permeability were significantly reduced or not significantly different.Under the low NaHS concentrations(25-200μmol·L-1),the activities of superoxide dismutase(SOD),catalase(CAT)and ascorbic acid peroxidase(APX)in leaves under saline-alkali stress all increased to different degrees.However,the peroxidase(POD)activity and free amino acid content decreased significantly or the difference was not significant.Under the high NaHS concentration(400μmol·L-1),the activities of SOD,CAT,APX,POD and the contents of free amino acid and proline in leaves under saline

关 键 词：硫化氢 裸燕麦 盐碱混合胁迫 幼苗生长 生理特性 

分 类 号：S512.6[农业科学—作物学] S311[农业科学—作物栽培与耕作技术]