外源硫化氢对盐胁迫下棉花幼苗生长及渗透调节系统的影响

Effects of Exogenous Hydrogen Sulfide on Growth and Osmotic Adjust System of Cotton Seedlings Under Salt Stress

【目的】探讨外源硫化氢提高棉花幼苗抗盐性的效应及机理。【方法】本试验以棉花品种新陆早48号为供试材料,试验采用营养液培养,为盐分(NaCl)、硫化氢(H2S)2因素随机组合,分别为盐分(NaCl:0、100、200 mmol/L)、硫化氢(H2S:0、20、50、100和500μmol/L),总计11个处理,每处理重复3次,研究外源H2S缓解盐胁迫对棉花幼苗生长、电解质渗出率、丙二醛(MDA)含量、渗透调节系统和活性氧(ROS)的抑制作用及其机制。【结果】与对照(CK)相比,随着NaCl浓度的增加,棉苗叶鲜重、叶干重、茎鲜重、茎干重、根干重、根冠比、可溶性糖(SS)含量均呈下降趋势;电解质渗出率、氧自由基(O2-·)产生速率、MDA、游离氨基酸、脯氨酸(Pro)、苹果酸、柠檬酸和过氧化氢(H2O2)含量呈上升趋势。相同浓度盐分处理施加外源H2S后,随着H2S浓度的增加,棉苗生物量及SS含量呈先上升后下降趋势,电解质渗出率、O2-·产生速率、MDA、游离氨基酸、Pro、苹果酸、柠檬酸和过氧化氢(H2O2)含量呈先下降后上升的趋势。【结论】盐胁迫对棉花幼苗生长有抑制作用,且随盐浓度的增加,其生长受抑制和渗透胁迫程度加剧,外源H2S通过提高棉花幼苗渗透调节物质积累量并降低活性氧积累,减少盐胁迫对棉花幼苗细胞膜的危害,增强抗盐性。

【Objective】In this experiment,the cotton variety Gossypium hirsutum L.cv.Xinluzao 48 was used as the test material.【Method】Nutrient solution was used in the experiment.In the experiment,2 factors including salt(NaCl analysis pure,0,100,200 mmol/L)and H2S(NaHS analysis pure,0,20,50,100 and 500 mol/L)were randomly combined.A total of 11 treatments were performed(as shown in Table 1),and each treatment was repeated for 3 times.The inhibitory effects of exogenous H2S on cotton seedling growth,electrolyte exudation rate,Malondialdehyde(MDA)content,osmotic regulation system and reactive oxygen species(ROS)were studied.【Result】The results showed that compared with CK,with the increase of NaCl concentration,the cotton seedling fresh leaf weight,leaf dry weight,stem fresh weight,stem dry weight,root dry weight,root-shoot ratio,soluble sugar content(SS)showed a downward trend;Electrolyte leakage rate,malondialdehyde(MDA)content,free amino acid content,proline(Pro)content,malic acid content,citric acid content,oxygen free radical(O2-·)production rate and hydrogen peroxide(H2O2)showed an upward trend.After the same concentration of salt treatment was applied to the external source H2S,with the increase of H2 S concentration,cotton seedling biomass and soluble sugar content(SS)showed an upward and downward trend;Electrolyte leakage rate,malondialdehyde(MDA)content,free amino acid content,proline(Pro)content,malic acid content,citric acid content,oxygen radical production rate and hydrogen peroxide(H2O2)decreased first and then increased.【Conclusion】The salt stress inhibited the growth of cotton seedlings and osmotic stress was aggravated with the increase of salt concentration.Exogenous hydrogen sulfide can increase the accumulation of osmotic adjustment substances and reduce the accumulation of reactive oxygen species in cotton seedlings,reduce the damage of salt stress on the cell membrane of cotton seedlings,and enhance salt resistance.