中国农业科学 ›› 2025, Vol. 58 ›› Issue (16): 3327-3344.doi: 10.3864/j.issn.0578-1752.2025.16.015

• 植物保护 • 上一篇    下一篇

纳米氧化镁诱导烟草抗青枯病的作用机理

陈娟妮1(), 陈品璐1, 李珏2, 谢蒙潇1, 李欣蓓2,*(), 丁伟1,*()   

  1. 1 西南大学植物保护学院,重庆 400715
    2 中国烟草总公司河南省公司,郑州 450018
  • 收稿日期:2025-05-11 接受日期:2025-06-12 出版日期:2025-08-11 发布日期:2025-08-11
  • 通信作者:
    丁伟,E-mail:
    李欣蓓,E-mail:
  • 联系方式: 陈娟妮,E-mail:chenhuanni521@126.com。
  • 基金资助:
    重庆市自然科学基金面上项目(CSTB2023NSCQ-MSX0764); 中国烟草总公司河南省公司“揭榜挂帅”项目(1730689845804)

Mechanism of Tobacco Resistance to Bacterial Wilt Induced by Magnesium Oxide Nanoparticles

CHEN JuanNi1(), CHEN PinLu1, LI Yu2, XIE MengXiao1, LI XinBei2,*(), DING Wei1,*()   

  1. 1 College of Plant Protection, Southwest University, Chongqing 400715
    2 Henan Branch of China National Tobacco Corporation, Zhengzhou 450018
  • Received:2025-05-11 Accepted:2025-06-12 Published:2025-08-11 Online:2025-08-11

摘要:

【目的】探究纳米氧化镁(MgO NPs)诱导烟草抗青枯病的效应及其作用机制,通过整合植物地上-地下协同响应机制,为揭示纳米材料诱导植物系统抗性的分子机理提供新的研究视角。【方法】采用灌根预处理方式,结合植物防御物质测定、qRT-PCR和高通量测序等方法评价纳米氧化镁处理后感病烟草植株地上部生理生化防御应答机制和地下部烟草根际微生态的变化。【结果】300 μg·mL-1 纳米氧化镁预处理对烟草青枯病防治效果最佳,接种后16 d的相对防效达到50.74%。与清水对照相比,纳米氧化镁预处理显著增强烟草体内的抗氧化酶活性,其中过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)和多酚氧化酶(PPO)活性分别提高63.9%、61.3%、72.8%和66.4%;300 μg·mL-1纳米氧化镁预处理后叶片脯氨酸和可溶性糖含量相比对照显著提高319.3%和131.0%,而丙二醛、过氧化氢和超氧阴离子水平相比对照显著降低;同时,纳米氧化镁预处理诱导烟草抗性基因表达量显著增强,并显著性改变烟草根际土壤微生物群落结构丰富度和多样性。与对照相比,纳米氧化镁预处理后烟草根际土壤芽孢杆菌属(Bacillus)、链霉菌属(Streptomyces)、腐质霉属(Humicola)、被孢霉属(Mortierella)、毛壳菌属(Chaetomium)等有益细菌和真菌显著富集,而雷尔氏菌属(Ralstonia)、链球菌属(Streptococcus)和镰孢菌属(Fusarium)等病原菌的相对丰度显著降低。田间验证表明,灌根施用300 μg·mL-1 纳米氧化镁对烟草青枯病的相对防效达到53.67%。【结论】纳米氧化镁可有效防控烟草青枯病并改善烟草根际微生态,具有开发成帮助烟草抵御病原菌侵染的新型纳米抗菌剂的潜力。

关键词: 纳米氧化镁, 烟草青枯病, 诱导抗性, 作用机理, 根际微生物

Abstract:

【Objective】The objective of this study is to explore the effect and mechanism of magnesium oxide nanoparticles (MgO NPs) in inducing tobacco resistance to bacterial wilt, and by integrating the aboveground and underground synergistic response mechanism of plants, it will provide a new research perspective for revealing the molecular mechanism of nanomaterials inducing systemic resistance in plants.【Method】The physiological and biochemical defense response mechanisms of the aboveground part and the changes of the rhizosphere microecology of the underground part of diseased tobacco plants after MgO NPs treatment were evaluated by root irrigation pretreatment, combined with methods such as the determination of plant defense substances, qRT-PCR and high-throughput sequencing. 【Result】 Pretreatment with 300 μg·mL-1 MgO NPs achieved optimal control efficacy against tobacco bacterial wilt, showing a relative control efficacy of 50.74% at 16 days post-inoculation. Compared with the water control, MgO NPs pretreatment significantly enhanced antioxidant enzyme activities in tobacco plants. The activities of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and polyphenol oxidase (PPO) were increased by 63.9%, 61.3%, 72.8%, and 66.4%, respectively. The contents of proline and soluble sugar in leaves pretreated with 300 μg·mL-1 MgO NPs were significantly increased by 319.3% and 131.0% compared with the control, while malondialdehyde (MDA), hydrogen peroxide, and superoxide anion levels were significantly decreased compared with the control. Concurrently, MgO NPs pretreatment significantly enhanced the expression level of tobacco resistance genes and significantly changed the richness and diversity of microbial community in tobacco rhizosphere soil. Compared with the control group, beneficial bacteria and fungi such as Bacillus, Streptomyces, Humicola, Mortierella and Chaetomium in tobacco rhizosphere soil were significantly enriched after pretreatment with MgO NPs. The relative abundance of pathogens such as Ralstonia, Streptococcus and Fusarium decreased significantly. In field trials, the drench application of 300 μg·mL-1 MgO NPs demonstrated a relative control efficacy of 53.67% against tobacco bacterial wilt.【Conclusion】MgO NPs can effectively control tobacco bacterial wilt while improving the rhizosphere microecology of tobacco plants, exhibiting potential for development as a novel nano-antibacterial agent to enhance tobacco’s defense against pathogen invasion.

Key words: magnesium oxide nanoparticles, tobacco bacterial wilt, induced resistance, action mechanism, rhizosphere microorganism