摘要
以春小麦新品种陇春27和陇春30为供试材料,研究了不同浓度NaCl(0,25,100和200mmol·L^(-1))胁迫下2种小麦幼苗的抗坏血酸(AsA)-谷胱甘肽(GSH)循坏中抗氧化物含量和相关酶活性的变化.盐胁迫下2种小麦根中AsA、脱氢抗坏血酸(DHA)以及AsA/DHA比值均有不同程度地增加.与对照相比,25mmol·L^(-1) NaCl处理使陇春27号根中GSH含量减少而氧化型谷胱甘肽(GSSG)含量升高,陇春30号中含量均减少.100和200mmol·L^(-1) NaCl处理下2种小麦根GSSG含量均增加.盐胁迫诱导2种小麦根抗坏血酸过氧化物酶(APX)活性均呈现先下降后上升的变化趋势.200mmol·L^(-1) NaCl处理的陇春27根和25mmol·L^(-1) NaCl处理的陇春30号根中抗坏血酸氧化酶(AAO)无显著变化,其他盐浓度胁迫导致陇春27号根中该酶活性都升高,而陇春30根活性下降.不同的是,盐处理下2种小麦根中脱氢抗坏血酸还原酶(MDHAR)活性与AAO活性变化不同,呈现出相反的变化趋势.在25mmol·L^(-1) NaCl处理的陇春27根中脱氢抗坏血酸还原酶(DHAR)和谷胱甘肽还原酶(GR)活性无显著变化,其他浓度的盐处理下2种小麦幼苗根中的这2种酶活性较对照相比均显著增加.结果表明,盐胁迫下2种小麦根可通过提高AsA和DHA的含量及AsA/DHA的比值提高AsA-GSH循环的循环率,增强幼苗的抗氧化能力,缓解NaCl对小麦幼苗造成的氧化损伤;此外,盐诱导的陇春27根中AsA的积累可能与DHAR活性升高有关,而陇春30号AsA含量的增加可能是由于AAO活性的抑制及MDHAR和DHAR活性的增强.
The changes of antioxidant contents and related enzyme activities in AsA-GSH cycle are studied in spring wheat cultivars Longchun 27 and Longchun 30 exposed to different NaCl concentrations(0,25,100 and 200 mmol·L-1).The amount of AsA,dehydroascorbate(DHA)and AsA/DHA in two wheat roots are incrensed in response to salt stress.Compared with the control,the content of GSH is deceased under 25 mmol·L-1 NaCl treatment in Longchun 27,but oxidized glutathione(GSSG)content is increased in Longchun 30.GSH and GSSG contents in two wheat roots significantly are increased under 100 and 200 mmol·L-1 NaCl treatments.The activity of ascorbate peroxidase(APX)are decreased in response to low NaCl concentration but increased to high salinity in two wheat roots.There are no significant changes of ascorbate oxidase(AAO)activity in Longchun 27 wheat roots treated with 200 mmol·L-1 NaCl and Longchun 30 treated with 25 mmol·L-1 NaCl,but the other NaCl concentrations is increased the activity of AAO in Longchun 27 and decreased in Longchun 30.In contrast,the activities of dehydrogenated ascorbate reductase(MDHAR)and AAO in two wheat roots exposed to NaCl treatments show the opposite trend.Compared with the control,DHAR and glutathione reductase(GR)activities have no significant change in Longchun 27 wheat roots treated with 25 mmol·L-1 NaCl,both DHAR and GR activities are increased significantly in other concentrations of salt treatments.The results show that two wheat roots in response to salt treatments can improve the circulation rate of AsA-GSH cycle by increasing AsA level,DHA content and AsA/DHA,as well enhance the antioxidant capacity of seedlings and alleviate the oxidative damage caused by NaCl.Additionally,AsA accumulation in salt-stressed Longchun 27 may be related to the increase of DHAR activity,and the increase of AsA content in Longchun 30 may be due to the inhibition of AAO activity,and the increases of MDHAR and DHAR activities.
作者
杨颖丽
吕丽荣
李晶
李翠祥
李琼
YANG Ying-li;LV Li-rong;LI Jing;LI Cui-xiang;LI Qiong(College of Life Science,Northwest Normal University,Lanzhou 730070,Gansu,China)
出处
《西北师范大学学报（自然科学版）》
CAS
北大核心
2018年第3期65-70,82,共7页
Journal of Northwest Normal University(Natural Science)
基金
国家自然科学基金资助项目(31470464
31360094)
