Pham Dinh Chuong, Nguyen Thi Hiep, Ngoc Uyen Thi Phan, Le Ngoc Thuy Trang, Tran Tuong Vi, Nguyen Dai Hai
Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City 700000, Vietnam.
Tissue Engineering and Regenerative Medicine, Department of Biomedical Engineering, International University, Vietnam National University-HCMC (VNU-HCMC), Ho Chi Minh City 700000, Vietnam.
J Nanosci Nanotechnol. 2018 Aug 1;18(8):5299-5305. doi: 10.1166/jnn.2018.15400.
Rice (Oryza sativa L.) is one of the major staple food crops of nearly two-third of the world's population. However, rice blast caused by fungus Pyricularia oryzae is generally considered the most serious disease of cultivated rice worldwide due to its extensive distribution and destructiveness under favourable climatic conditions. In this report, the combination between chitosan (CS) and silver (Ag), Ag@CS, was introduced for antifungal activity against Pyricularia oryzae extracted from blast-infected leaves. In detail, Ag@CS nanoparticles (NPs) were first synthesized and further mixed with Trihexad 700 WP (Tri), Ag@CS-Tri, against the fungus by agar diffusion method. The prepared Ag@CS-Tri NPs were characterized by Fourier transform infrared (FTIR), dynamic light scattering (DLS), transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). In aqueous condition, Ag@CS-Tri NPs were successfully prepared and existed as spherical NPs with particle size of 17.26 ± 0.89 nm, which is an ideal size for their uptake into plant cells, indicating that the size of their parentally Ag@CS NPs is small enough to combine Tri, and their diameter is large enough to effectively penetrate the cellular membrane and kill fungi. More importantly, the antifungal property of Ag@CS-Tri NPs was significantly increased with inhibition zone around 25 nm compared with only around 12 nm of Ag@CS at the same concentration of Ag (2 ppm) and CS (4000 ppm). These results demonstrated that the synergistic effect of Tri and Ag@CS NPs can be a potential candidate with high antifungal activity for the use of antibiotics in agriculture.
水稻（Oryza sativa L.）是世界近三分之二人口的主要主食作物之一。然而，由稻瘟病菌（Pyricularia oryzae）引起的稻瘟病，因其广泛分布且在有利气候条件下具有破坏性，通常被认为是全球栽培水稻最严重的病害。在本报告中，引入了壳聚糖（CS）与银（Ag）的组合，即Ag@CS，用于对从稻瘟病感染叶片中提取的稻瘟病菌的抗真菌活性研究。具体而言，首先合成了Ag@CS纳米颗粒（NPs），并进一步将其与700 WP三唑酮（Tri）混合，通过琼脂扩散法制备了用于抗真菌的Ag@CS-Tri。采用傅里叶变换红外光谱（FTIR）、动态光散射（DLS）、透射电子显微镜（TEM）、X射线衍射（XRD）和热重分析（TGA）对制备的Ag@CS-Tri NPs进行了表征。在水性条件下，成功制备了Ag@CS-Tri NPs，其呈球形，粒径为17.26±0.89 nm，这是其被植物细胞摄取的理想尺寸，表明其母体Ag@CS NPs的尺寸小到足以结合Tri，且其直径大到足以有效穿透细胞膜并杀死真菌。更重要的是，在相同浓度的Ag（2 ppm）和CS（4000 ppm）下，Ag@CS-Tri NPs的抑菌圈约为25 nm，而Ag@CS仅约为l2 nm，其抗真菌性能显著提高。这些结果表明，Tri与Ag@CS NPs的协同效应可能是一种具有高抗真菌活性的潜在候选物，可用于农业抗生素。
