Journal of Integrative Agriculture

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干旱锻炼促进小麦拔节期干旱胁迫下的幼穗发育的生理机制

  

  • 收稿日期:2024-10-31 修回日期:2025-02-19

Drought priming enhances young spike development in wheat under drought stress during stem elongation

Mengting He1, Hanxiao Li1, Zhuangzhuang Sun1, Xiangnan Li2, Qing Li1, Jian Cai1, Qin Zhou1, Yingxin Zhong1, Xiao Wang1#, Dong Jiang1   

  1. 1 National Technique Innovation Center for Regional Wheat Production/Key Laboratory of Crop Ecophysiology, Ministry of Agriculture/Nanjing Agricultural University, Nanjing 210095, China

    2 Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China

  • Received:2024-10-31 Revised:2025-02-19
  • About author:#Correspondence Xiao Wang, Tel/Fax: +86-25-84399627, E-mail: xiaowang@njau.edu.cn
  • Supported by:

    This study was supported by the projects of the National Key Research and Development Program of China (2024YFD2301305), the Jiangsu Innovation Support Program for International Science and Technology Cooperation Project, China (BZ2023049), the projects of the National Natural Science Foundation of China (32272213 and 31771693), the China Agriculture Research System (CARS-03), and the Jiangsu Collaborative Innovation Center for Modern Crop Production, China (JCIC-MCP).

摘要:

干旱胁迫是制约小麦产量的关键环境因子,其中拔节期干旱对穗分化的抑制作用尤为突出。本研究基于作物逆境胁迫记忆理论,系统解析了三叶期干旱锻炼对拔节期穗发育的生理调控机制。研究通过对三叶期小麦施加干旱锻炼与拔节期干旱胁迫试验,揭示了干旱锻炼通过碳代谢重编程稳定幼穗分化的生理机制。研究表明:干旱锻炼显著提升植株的生理适应能力。在拔节期干旱胁迫下,经过锻炼植株旗叶光合速率较未锻炼植株提25.7%,叶片水势增加17.4%,并有效缓解氧化损伤(过氧化氢和丙二醛含量分别降低30.6%和11.1%)叶片碳代谢关键酶活性分析发现,己糖激酶和果糖激酶的活性分别增加了170%和236%,驱动了碳代谢流稳态建立,从而增加了小穗和可育小花的形成,最终实现穗粒数13.8%的显著提升。本研究创新性地揭示了干旱锻炼通过“碳代谢稳态和穗器官建成”协同调控增强小麦耐逆性的生理机制,为作物抗逆栽培理论提供了重要补充,也为粮食安全生产提供了创新性解决方案。

Abstract:

Drought stress is a significant environmental stressor that can have detrimental effects on crop yields, especially during stem elongation.  Drought priming has emerged as a promising technique for enhancing plant drought tolerance.  However, the effects of drought priming on the differentiation process of spike and its physiological basis of wheat are not clear.  In this study, we investigated the effects of drought priming on the development of spike under drought stress by applying drought priming at the three-leaf stage and drought stress during stem elongation.  Our study demonstrated that drought priming significantly increased the photosynthetic rate of flag leaves by approximately 25.7% and improved leaf water potential by 17.4% during drought stress.  Moreover, it mitigated oxidative damage, reducing hydrogen peroxide and malondialdehyde levels by 30.6 and 11.1%, respectively, during stem elongation.  Drought priming also markedly enhanced the activity of key carbon metabolism enzymes, hexokinase and fructokinase, by 170.0 and 236.0%, respectively.  This improved carbon metabolism stabilized spike differentiation, leading to increased spikelet and floret primordia formation.  Ultimately, drought priming achieved a 13.8% increase in kernel number per spike, demonstrating its potential to improve grain yield under drought conditions.  This study innovatively reveals the "carbon homeostasis-spike development" coordination mechanism underlying drought priming-enhanced reproductive stress tolerance. The findings advance our understanding of stress memory spatiotemporal regulation in crops and offer transformative solutions for stabilizing wheat production under climate change scenarios.

Key words: wheat , drought priming ,  , spike differentiation , carbon metabolism