草地学报 ›› 2024, Vol. 32 ›› Issue (3): 763-771.DOI: 10.11733/j.issn.1007-0435.2024.03.012

• 研究论文 • 上一篇    下一篇

甜菜碱对低温下苜蓿种子萌发中呼吸电子传递的影响

王婕1, 刘美君1, 赵尧尧1, 张政1, 卫丹丹2, 龚梁祝1, 胡轩铭1   

  1. 1. 新疆农业大学草业学院; 西部干旱区草地资源与生态教育部重点实验室; 新疆草地资源与生态重点实验室, 新疆 乌鲁木齐 830052;
    2. 忻州师范学院, 山西 忻州 034000
  • 收稿日期:2023-09-11 修回日期:2023-11-10 出版日期:2024-03-15 发布日期:2024-04-03
  • 通讯作者: 刘美君,E-mail:Lebaby7@163.com
  • 作者简介:王婕(1998-),女,汉族,新疆博乐人,硕士研究生,主要从事植物逆境生理研究,E-mail:WJ220466@163.com
  • 基金资助:
    农业生物育种重大专项-新疆地区耐盐碱抗旱高产苜蓿新品种设计与培育(2022ZD0401104);新疆维吾尔自治区自然科学基金项目(2022D01A185);国家自然科学基金(32360346)资助

Effects of Betaine on Respiratory Electron Transport of Alfalfa Seeds During Germination Under Low Temperature

WANG Jie1, LIU MEI-jun1, ZHAO Yao-yao1, ZHANG Zheng1, WEI Dan-dan2, GONG Liang-zhu1, HU Xuan-ming1   

  1. 1. Pratacultural College of Xinjiang Agricultural University;Key Laboratory of Grassland Resources and Ecology of Ministry of Education in Western Arid Areas;Xinjiang Key Laboratory of Grassland Resources and Ecology, Urumqi, Xinjiang 830052, China;
    2. Xinzhou Normal University, Xinzhou, Shanxi Province 034000, China
  • Received:2023-09-11 Revised:2023-11-10 Online:2024-03-15 Published:2024-04-03

摘要: 呼吸作用是种子萌发的唯一能量来源。本研究以'新牧4号'紫花苜蓿(Medicago sativa L.'Xinmu No.4')为试验材料,探究了甜菜碱对低温下苜蓿萌发种子呼吸电子传递的影响。结果表明:低温抑制苜蓿种子的发芽率,但没有终止种子萌发进程;延长萌发时间,最终种子的萌发率与20℃下无差异。外施15 mmol·L-1甜菜碱提高了低温下种子发芽率、发芽势、发芽指数,缩短低温下种子全部萌发的时间从而促进种子萌发,且温度越低,促进作用越大。甜菜碱提高了低温下种子呼吸速率,产生ATP的细胞色素C氧化酶呼吸速率及其在总呼吸中的占比显著增加,保证了苜蓿种子萌发所需的能量。此外,甜菜碱增加了交替氧化酶呼吸速率,减少了活性氧的产生,并且提高了苜蓿种子内SOD,POD,CAT活性,从而减少了H2O2的积累,有效缓解低温下种子的氧化伤害,维持低温下苜蓿种子较高的萌发速度,缩短萌发时间。

关键词: 紫花苜蓿, 低温胁迫, 甜菜碱, 种子萌发, 呼吸电子传递

Abstract: Respiration is the only source of energy during seed germination. In this study,the effect of betaine on the respiratory electron transfer of alfalfa germinating seeds at low temperature was investigated using 'Xinmu No.4' alfalfa (Medicago sativa L. 'Xinmu No.4') as experimental material. The results showed that low temperatures significantly inhibited the germination rate of alfalfa seeds,but did not terminate the seed germination process. Prolonging the time of germination under low temperature,the final alfalfa seeds could still achieve a high germination rate and did not differ from 20℃. The external application of 15 mmol·L-1 betaine significantly increased the germination rate,germination potential,and germination index of seeds at low temperatures,and shortened the time for all seeds to germinate at low temperatures,thus promoting seed germination. The promotion of betaine to alfalfa seed germination was increased with the decline in temperature. Betaine significantly increased the respiration rate of alfalfa seeds at low temperatures,in which the respiration rate of cytochrome coxidase (COX),which produces ATP,and the percentage of COX respiration in total respiration were significantly increased,which ensured the energy supply required for alfalfa seed germination. In addition,the external application of betaine increased the respiration rate of alternative oxidase (AOX),reduced the production of reactive oxygen species (ROS),and increased the activities of SOD,POD,and CAT in alfalfa seeds,thereby reducing the accumulation of H2O2,effectively alleviating the oxidative damage to the seeds at low temperatures. By this,a higher germination rate of alfalfa seeds was maintained and the germination time was shortened by betaine during seed germination of alfalfa under low temperature.

Key words: Alfalfa, Low temperature stress, Betaine, Seed germination, Respiratory electron transfer

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