| 摘要: |
| [目的]探讨盐胁迫对苜蓿幼苗不同器官生长及抗氧化酶系统的影响,为苜蓿植被恢复技术的研发提供理论参考.[方法]以新牧一号(盐忍耐品种)和北极星(盐敏感品种)2个苜蓿品种为材料,以0 mmol/L NaCl处理为对照,用200 mmol/L NaCl胁迫处理,测定萌发7 d苜蓿幼苗芽、根生长及其H2O2、丙二醛(MDA)含量,相对质膜透性、抗氧化保护酶活性及其同功酶的变化.[结果]200 mmol/L NaCl胁迫抑制了苜蓿幼苗的生长,并导致芽、根H2O2、MDA含量及相对质膜透性升高,但新牧一号芽、根器官均表现出比北极星较低程度的生长抑制或质膜损伤.盐胁迫后超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)、过氧化氢酶(CAT)、过氧化物酶(POD)的活性均明显增加.CAT和POD对活性氧的清除具有器官差异性,CAT活性在芽中较强,POD则与之相反.SOD -Ⅱ、APX -Ⅰ、POD -Ⅲ及POD -Ⅳ为芽、根中盐胁迫敏感的同功酶谱带.[结论]苜蓿盐忍耐品种通过更强的抗氧化保护能力,降低了盐胁迫对其幼苗的损伤. |
| 关键词: 紫花苜蓿 盐胁迫 植被恢复 活性氧 抗氧化酶 同功酶 |
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| 基金项目:国家自然科学基金，国家重点基础研究发展规划(973计划)，西北农林科技大学拔尖人才支持计划 |
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| Physiological and biological responses of alfalfa shoots and roots to salt stress |
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| Abstract: |
| 【Objective】 The study was carried out to reveal the changes of growth and antioxidant system in different organs of alfalfa seedling under salt stress and to provide some support for the study on alfalfa vegetation resumption.【Method】 Two alfalfa cultivars,Xinmu No.1 (tolerant cultivar) and Northstar (sensitive cultivar) were used as the plant materials,and 0,200 mmol/L NaCl was used as control and stress treatment respectively.The study analyzed the seedling growth,H2O2 contents,MDA contents, membrane damage,activity and isozymes of antioxidant enzymes of alfalfa shoots and roots treated 7 days by 200 mmol/L NaCl.【Result】 NaCl stress inhibited the growth of alfalfa shoots and roots,and resulted in the increase of H2O2,MDA contents and membrane damage. Lower degree of growth restraint effect and membrane damage of shoot and root organs were exhibited in Xinmu No.1 than Northstar.Under salt stress,antioxidant enzyme activity including superoxide dismutase (SOD),ascorbate peroxidase (APX),catalase (CAT) and peroxidase (POD) significantly increased.The capability of scavenging reactive oxygen species (ROS) took on organ difference in CAT and POD.The CAT activity in shoot was higher than that in root,but reversed in POD.SOD Ⅱ,APX Ⅰ,POD Ⅲ and POD Ⅳ were identified as sensitive isozyme bands to salt stress.【Conclusion】 Tolerant alfalfa cultivar can reduce the damage by enhanced antioxidant protective ability under salt stress. |
| Key words: alfalfa (Medicago sativaL.) salt stress vegetation restoration ROS antioxidant enzyme isozyme |
