Chen Juanni, Wu Lintong, Lu Mei, Lu Shasha, Li Ziyan, Ding Wei
Laboratory of Natural Products Pesticide, College of Plant Protection, Southwest University, Chongqing, China.
Front Microbiol. 2020 Mar 12;11:365. doi: 10.3389/fmicb.2020.00365. eCollection 2020.
Engineered nanoparticles have provided a basis for innovative agricultural applications, specifically in plant disease management. In this interdisciplinary study, by conducting comparison studies using macroscale magnesium oxide (mMgO), we evaluated the fungicidal activity of MgO nanoparticles (nMgO) against soilborne and for the first time under laboratory and greenhouse conditions. studies revealed that nMgO could inhibit fungal growth and spore germination and impede sporangium development more efficiently than could macroscale equivalents. Indispensably, direct contact interactions between nanoparticles and fungal cells or nanoparticle adsorption thereof were found, subsequently provoking cell morphological changes by scanning electron microscopy/energy-dispersive spectrometry (SEM/EDS) and transmission electron microscopy (TEM). In addition, the disturbance of the zeta potential and accumulation of various modes of oxidative stress in nMgO-exposed fungal cells accounted for the underlying antifungal mechanism. In the greenhouse, approximately 36.58 and 42.35% decreases in tobacco black shank and black root rot disease, respectively, could testify to the efficiency by which 500 μg/ml of nMgO suppressed fungal invasion through root irrigation (the final control efficiency reached 50.20 and 62.10%, respectively) when compared with that of untreated controls or mMgO. This study will extend our understanding of nanoparticles potentially being adopted as an effective strategy for preventing diversified fungal infections in agricultural fields.
工程纳米粒子为创新型农业应用提供了基础，特别是在植物病害管理方面。在这项跨学科研究中，我们通过使用宏观氧化镁（mMgO）进行对比研究，首次在实验室和温室条件下评估了氧化镁纳米粒子（nMgO）对土传真菌的杀菌活性。研究表明，与宏观等效物相比，nMgO能更有效地抑制真菌生长和孢子萌发，并阻碍孢子囊发育。不可忽视的是，发现纳米粒子与真菌细胞之间存在直接接触相互作用或纳米粒子对其的吸附作用，随后通过扫描电子显微镜/能谱仪（SEM/EDS）和透射电子显微镜（TEM）观察到细胞形态发生了变化。此外，暴露于nMgO的真菌细胞中ζ电位的扰动和各种氧化应激模式的积累解释了其潜在的抗真菌机制。在温室中，与未处理的对照或mMgO相比，500μg/ml的nMgO通过根部灌溉抑制真菌入侵，烟草黑胫病和黑根腐病分别减少了约36.58%和42.35%（最终防治效果分别达到50.20%和62.10%）。这项研究将扩展我们对纳米粒子可能作为预防农业领域多种真菌感染的有效策略的理解。
