不同时期喷施NaHS对盐碱胁迫下裸燕麦叶片渗透调节物质和抗氧化活性的影响

Effects of spraying Na HS at different growth stages on osmotic adjustment substance and antioxidant activity in leaves of naked oat under saline-alkali stress

为确定盐碱条件下裸燕麦的硫化氢(H;S)最佳施用时期和适宜浓度,采用盆栽土培试验,分别于裸燕麦幼苗期、拔节期、抽穗期、开花期和灌浆期喷施H;S供体硫氢化钠(Na HS)溶液(0、25、50、100、200和400μmol·L^(-1)),研究H;S对盐碱混合(Na Cl∶Na_(2)SO_(4)∶Na HCO_(2)∶Na_(2)CO_(3)摩尔比为12∶8∶9∶1)胁迫下裸燕麦叶片渗透调节物质含量和抗氧化活性的影响。结果表明:喷施时期、Na HS浓度及二者的交互作用显著促进或抑制盐碱胁迫下裸燕麦叶片渗透调节物质含量和抗氧化活性;与同一时期不喷施Na HS相比,幼苗期喷施50和200μmol獉L^(-1)Na HS分别显著提高ABTS·;清除活性和FRAP抗氧化活性,喷施400μmol·L^(-1)Na HS提高总酚含量、O_(2)清除活性和总还原活性的效果最好;拔节期喷施50、100和400μmol·L^(-1)Na HS分别显著提高可溶性蛋白、类黄酮和脯氨酸含量30.43%、31.44%和258.59%;抽穗期喷施50、100和400μmol·L^(-1)Na HS分别显著提高原花色素、可溶性糖和游离氨基酸含量150.57%、42.71%和197.93%;开花期喷施100μmol·L^(-1)Na HS的DPPH·清除活性显著提高93.98%,增幅最大;灌浆期喷施400和25μmol·L^(-1)Na HS分别提高K;含量和K;/Na;的作用最显著;喷施时期和Na HS浓度交互作用对裸燕麦叶片有机酸含量和獉OH清除活性无显著作用或表现为负效应。采用隶属函数分析综合评价不同时期喷施Na HS对裸燕麦叶片渗透调节和抗氧化活性影响,结果显示,拔节期和抽穗期喷施400μmol·L^(-1)Na HS的综合评价值最大。表明外源H;S能够通过提高渗透调节和抗氧化活性缓解裸燕麦盐碱胁迫,以拔节-抽穗期喷施400μmol·L^(-1)Na HS效果最佳。

In order to clarify the optimal application period and appropriate concentration of hydrogen sulfide (H;S),we sprayed H;S donor sodium hydrosulfide (Na HS) solution (0,25,50,100,200 and 400μmol·L^(-1)) at seedling,jointing,heading,flowering and filling stages of soil-potted naked oats to examine the effects of H;S on the content of osmotic adjustment substance and the antioxidant activity in leaves under salt-alkali mixed stress (Na Cl,Na_(2)SO_(4),Na HCO_(2),Na_(2)CO_(3)molar ratio is 12∶8∶9∶1).The results showed that spraying period,Na HS concentration,and their interaction significantly promoted or inhibited the content of osmotic adjustment substance and the antioxidant activity.Compared with non-spraying Na HS,spraying50 and 200μmol·L^(-1)Na HS at the seedling stage significantly increased the scavenging activity of ABTS·;and the antioxidant activity of FRAP;and spraying 400μmol·L^(-1)Na HS performed best in increasing the total phenol content,scavenging activity of O_(2)and total reducing activity.Spraying 50,100,and 400μmol·L^(-1)Na HS at the jointing stage significantly increased the content of soluble protein,flavonoids,and proline by 30.43%,31.44%,and 258.59%,respectively.Spraying 50,100,and 400μmol·L^(-1)Na HS at the heading stage significantly increased the content of proanthocyanidins,soluble sugars and free amino acids by 150.57%,42.71%,and197.93%,respectively.Spraying 100μmol·L^(-1)Na HS at the flowering stage significantly increased the scavenging activity of DPPH·by 93.98%,with the greatest magnitude of enhancement.Spraying 400 and 25μmol·L^(-1)Na HS at the grouting period had the strongest effect on increasing the K;content and K;/Na;.The interaction between spraying period and Na HS concentration had no significant or negative effect on organic acid content and the scavenging activity of·OH in leaves.Using membership function analysis to comprehensively evaluate the effects of spraying Na HS at different periods on the osmotic adjustment and antioxidant activity of naked oat leaves showed that the comprehensive evaluation value of spraying 400μmol·L^(-1)Na HS at the jointing and heading stages was significantly higher than that of other concentrations at other periods.These results indicated that exogenous H;S can alleviate the salt-alkali stress of naked oat by improving osmotic regulation and antioxidant activity,with the best performance of spraying 400μmol·L^(-1)Na HS at the jointing-heading stage.