褪黑素引发对敖汉苜蓿种子碱性盐胁迫的缓解作用  

Responses of Aohan Alfalfa Seeds to Melatonin Priming under Alkaline Salt Stress

作　　者：毛培胜[1] 张晔[1] 黄琪 毛春力 唐嘉 孙铭[1] MAO Pei-sheng;ZHANG Ye;HUANG Qi;MAO Chun-li;TANG Jia;SUN Ming(Grassland Science Department,China Agricultural University,Key Laboratory of Pratacultural Science,Beijing Municipality,Beijing 100193,China)

机构地区：[1]中国农业大学草业科学系/草业科学北京市重点实验室,北京100193

出　　处：《中国草地学报》2020年第3期30-36,共7页Chinese Journal of Grassland

基　　金：国家现代牧草产业技术体系(CARS-34)资助。

摘　　要：采用100μmol/L褪黑素(MT)溶液和蒸馏水(WT)引发敖汉苜蓿种子,以未引发种子作为对照(CK-0),使用NaCl、Na2SO4、NaHCO3、Na2CO3配制为0、25mmol/L、50mmol/L混合碱性盐溶液(CK、25S、25J、50S、50J)进行胁迫处理,探索碱性盐胁迫下种子发芽率和抗氧化酶的变化,研究MT引发苜蓿种子对碱性盐胁迫的生理响应。结果表明,低浓度混合盐25S(pH 9.26)处理可以促进种子发芽,高浓度混合盐50J(pH 11.21)处理则抑制种子的发芽,而MT引发可以显著(P<0.05)缓解种子发芽率的下降。各碱性盐处理中,混合盐50J(pH 11.21)处理下种子丙二醛(MDA)含量达到最高水平,超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性却均处于最低水平,但SOD和POD活性对于盐胁迫的反应与CAT不同。在高浓度或高pH盐溶液(50S和25J)处理中,MT引发显著(P<0.05)降低了种子的膜脂过氧化程度,提高了SOD、POD和CAT活性。可见,MT通过增强抗氧化酶活性,降低膜脂过氧化损伤来维持种子的发芽能力。In the experiment,100μmol/L melatonin(MT)solution and distilled water(WT)were used to prime the seeds of Aohan alfalfa for 12 hours,and unprimed seeds were used as control(CK-0).Seed materials were treated with 0,25 and 50mmol/L mixed alkaline salt solution(CK,25S,25J,50S,50J)prepared by mixing NaCl,Na 2SO 4,NaHCO 3 and Na 2CO 3.The purpose of study was to explore the changes of alfalfa seeds germination rate and antioxidant enzymes under alkaline salt stress,and to study the physiological response of alfalfa seeds induced by MT to alkaline salt stress.The results showed that the 25S treatment of the low concentration mixed alkaline salt(pH 9.26)could promote seed germination.The 50J treatment of high concentration mixed alkaline salt(pH 11.21)could inhibit seed germination,while MT priming could significantly(P<0.05)alleviate the decline of seed germination.Within the treatments of alkaline salt,the content of MDA was the highest in the 50J with high concentration salt and pH 11.21,while the activities of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)were at the lowest level,but the response of SOD and POD to alkaline salt stress was different from CAT.In the treatments of high concentration(50S)or pH salt solution(25J),MT priming significantly(P<0.05)inhibited the action of membrane lipid peroxidation of seeds and increased activities of SOD,POD and CAT.It can be suggested that the germination ability of seeds could be maintained with MT priming by enhancing the activities of antioxidant enzymes and reducing damages of membrane lipid peroxidation.

关 键 词：种子引发 敖汉苜蓿 褪黑素 抗氧化酶 碱性盐胁迫 

分 类 号：S541.1[农业科学—作物学]