中国农业科学 ›› 2025, Vol. 58 ›› Issue (17): 3400-3417.doi: 10.3864/j.issn.0578-1752.2025.17.004

• 耕作栽培·生理生化·农业信息技术 • 上一篇    下一篇

外源褪黑素通过调控ABA-H2O2含量提高小麦幼苗抗旱性

苗童童(), 王隆金, 杨瑞婷, 代成成, 刘世超, 李楠, 李东晓*()   

  1. 河北农业大学农学院/省部共建华北作物改良与调控重点实验室/河北省作物生长调控实验室,河北保定 071001
  • 收稿日期:2025-02-05 接受日期:2025-07-04 出版日期:2025-09-01 发布日期:2025-09-02
  • 通信作者:
    李东晓,E-mail:
  • 联系方式: 苗童童,E-mail:3153281419@qq.com。
  • 基金资助:
    国家自然科学基金(32201908); 河北省自然科学基金(C2022204070)

Exogenous Melatonin Enhances Drought Resistance of Wheat Seedlings by Regulating Abscisic Acid and Hydrogen Peroxide Content

MIAO TongTong(), WANG LongJin, YANG RuiTing, DAI ChengCheng, LIU ShiChao, LI Nan, LI DongXiao-*()   

  1. College of Agronomy, Hebei Agricultural University/State Key Laboratory of North China Crop Improvement and Regulation Co-Constructed by Province and Ministry/Laboratory of Crop Growth Regulation of Hebei Province, Baoding 071001, Hebei
  • Received:2025-02-05 Accepted:2025-07-04 Published:2025-09-01 Online:2025-09-02

摘要:

【目的】明确外源褪黑素如何与逆境响应因子脱落酸(ABA)、过氧化氢(H2O2)互作以提高小麦抗旱性,并探讨其机理。【方法】以小麦品种济麦22和衡观35为试验材料,设计正常水分处理(CK)、外源褪黑素处理(MT)、干旱处理(DS)、干旱胁迫下施加褪黑素处理(DS+MT)、干旱胁迫下施加褪黑素和ABA抑制剂氟啶酮处理(DS+MT+Flu)、干旱胁迫下施加褪黑素和H2O2清除剂二苯基氯化碘盐(DS+MT+DPI)6个处理,重点研究小麦根系和地上植株的关键生理指标(叶绿素、净光合速率(Pn)、ABA、内源褪黑素、丙二醛(MDA)、超氧阴离子()、H2O2及其抗氧化酶活性)的变化及响应关系。【结果】正常条件下,施加外源MT可显著提高植株叶片和根系内源褪黑素含量,改善2个小麦品种幼苗的叶绿素a/b、Pn及根鲜重,增强植株超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性的同时,降低MDA、和叶片ABA含量。在干旱条件下,施加MT处理(DS+MT)能显著提高济麦22和衡观35的叶绿素总含量、Pn、蒸腾速率(Tr)、瞬时水分利用效率(WUET),较DS处理分别增幅为14.62%、26.22%、18.06%、6.92%和6.20%、49.32%、16.41%、28.89%;济麦22叶片和根系的SOD活性、CAT活性、MT含量较DS处理的增幅分别为2.66%、34.40%、136.72%和4.80%、25.96%、0.48%;衡观35叶片和根系的SOD活性、CAT活性、MT含量较DS处理的增幅分别为32.08%、24.08%、24.65%和83.51%、4.49%、61.80%。另外,与DS处理相比,DS+MT处理下济麦22和衡观35叶片ABA含量显著降低了36.94%、6.78%,叶片和根系MDA、H2O2含量也均显著降低。DS+MT+Flu、DS+MT+DPI处理进一步增强了MT对济麦22地上部干重、SOD活性的提升作用,同时显著降低ABA、内源MT及过氧化产物含量;对衡观35呈负调节效应,降低了叶绿素含量、叶面积和地上部鲜重,提高了POD活性和叶片MDA、ABA含量,显示出品种差异性。【结论】在干旱胁迫下,施加外源褪黑素可有效提高小麦幼苗抗旱性,且褪黑素存在依赖ABA与非依赖ABA响应因子2种途径进行抗旱;ABA与H2O2作为MT下游信号,表现为ABA和MT之间既存在拮抗作用又有协同关系、H2O2和MT之间具有拮抗效应,ABA与H2O2的互作关系存在品种和部位差异性。

关键词: 褪黑素, 小麦幼苗, 脱落酸, 过氧化氢, 抗旱

Abstract:

【Objective】This research has been conducted to clarify how exogenous melatonin interacts with stress responsive factors of abscisic acid (ABA) and hydrogen peroxide (H2O2) to enhance wheat drought resistance of wheat and explore the underlying mechanism.【Method】Wheat varieties Jimai 22 and Hengguan 35 were used as experimental materials, and six treatments were designed: normal water treatment (CK), exogenous melatonin treatment (MT), drought treatment (DS), melatonin treatment under drought stress (DS+MT), melatonin and ABA inhibitor fluoridone treatment under drought stress (DS+MT+Flu), and the treatment of melatonin and H2O2 scavenger diphenyl chloride iodide salt (DS+MT+DPI) under drought stress. The key physiological indicators of wheat roots and above-ground plants (chlorophyll, net photosynthetic rate (Pn), ABA, endogenous melatonin, malondialdehyde (MDA), superoxide anion (), H2O2 and their antioxidant enzyme activities) were studied, focusing on the changes and response relationships in wheat roots and aboveground plants.【Result】Under normal conditions, the application of exogenous MT could significantly increase the endogenous melatonin content in plant leaves and roots, improve the chlorophyll a/b, Pn, and root fresh weight of the two wheat varieties, enhance the activity of superoxide dismutase (SOD) and peroxidase (CAT) in plants, and reduce the content of MDA, , and leaf ABA. Under drought conditions, applying MT treatment (DS+MT) could significantly increase the total chlorophyll content, Pn, transpiration rate (Tr), instantaneous water use efficiency (WUET) of Jimai 22 and Hengguan 35, with the increases compared with the DS treatment being 14.62%, 26.22%, 18.06%, 6.92% and 6.20%, 49.32%, 16.41%, 28.89%, respectively; Additionally, the SOD activity, CAT activity and MT content in the leaves and roots of Jimai 22 increased by 2.66%, 34.40%, 136.72% and 4.80%, 25.96%, 0.48%, respectively, compared with DS treatment. The SOD activity, CAT activity and MT content in the leaves and roots of Hengguan 35 increased by 32.08%, 24.08%, 24.65% and 83.51%, 4.49%, 61.80%, respectively, compared with DS treatment. At the same time, compared with DS treatment, DS+MT treatment showed better effects on Jimai 22 and Hengguan 35, the leaf ABA content significantly decreased by 36.94% and 6.78%, while the MDA, H2O2, and , contents in the leaves and roots also significantly decreased. The DS+MT+Flu and DS+MT+DPI treatments further enhanced the improvement effect of MT on the aboveground dry weight and SOD activity of Jimai 22, while significantly reducing the contents of ABA, endogenous MT, and peroxidation product; but it showed a negative regulatory effect on Hengguan 35, such as reducing chlorophyll content, leaf area, and aboveground fresh weight, whereas increasing POD activity and leaf MDA and ABA content. All these demonstrated the differences between the varieties.【Conclusion】Under drought stress, the application of exogenous melatonin could effectively enhance the drought resistance of wheat seedlings, and melatonin had two pathways for drought resistance: ABA-dependent and ABA-independent response factors; ABA and H2O2 act as downstream signals of MT. There were both antagonistic and synergistic relationships between ABA and MT, and an antagonistic effect between H2O2 and MT. The interaction between ABA and H2O2 varied by variety and plant parts.

Key words: melatonin, wheat seedlings, abscisic acid, hydrogen peroxide, combat drought