CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow 226 001, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow 226 001, India; Department of Botany, Lucknow University, Hasanganj, Lucknow 226 007, India.
Pestic Biochem Physiol. 2019 Jun;157:45-52. doi: 10.1016/j.pestbp.2019.03.005. Epub 2019 Mar 5.
Herein, we describe the enhanced antifungal activity of silver nanoparticles biosynthesized by cell free filtrate of Trichoderma viride (MTCC 5661) in comparison to chemically synthesized silver nanoparticles (CSNP) of similar shape and size. Biosynthesized silver nanoparticles (BSNP) enhanced the reduction in dry weight by 20 and 48.8% of fungal pathogens Fusarium oxysporum and Alternaria brassicicola respectively in comparison to their chemical counterparts (CSNP). Nitroblue tetrazolium and Propidium iodide staining demonstrated the higher generation of superoxide radicals lead to higher death in BSNP treated fungus in comparison to CSNP. Scanning electron microscopy of A. brassicicola revealed the osmotic imbalance and membrane disintegrity to be major cause for fungal cell death after treatment with BSNP. To gain an insight into the mechanistic aspect of enhanced fungal cell death after treatment of BSNP in comparison to CSNP, stress responses and real time PCR analysis was carried out with A. brassicicola. It revealed that generation of ROS, downregulation of antioxidant machinery and oxidative enzymes, disruption of osmotic balance and cellular integrity, and loss of virulence are the mechanisms employed by BSNP which establishes them as superior antifungal agent than their chemical counterparts. With increasing drug resistance and ubiquitous presence of fungal pathogens in plant kingdom, BSNP bears the candidature for new generation of antifungal agent.
在此，我们描述了由绿色木霉（MTCC 5661）无细胞滤液生物合成的银纳米粒子的增强抗真菌活性，与具有相似形状和大小的化学合成银纳米粒子（CSNP）相比。与化学合成的银纳米粒子（CSNP）相比，生物合成的银纳米粒子（BSNP）分别使真菌病原体尖孢镰刀菌和芸薹链格孢的干重减少了 20%和 48.8%。氮蓝四唑和碘化丙啶染色表明，BSNP 处理的真菌中产生的超氧自由基更多，导致死亡的数量更多。BSNP 处理芸薹链格孢的扫描电子显微镜显示，渗透压失衡和膜完整性破坏是真菌细胞死亡的主要原因。为了深入了解 BSNP 处理与 CSNP 相比增强真菌细胞死亡的机制，我们对 A. brassicicola 进行了应激反应和实时 PCR 分析。结果表明，ROS 的产生、抗氧化机制和氧化酶的下调、渗透压平衡和细胞完整性的破坏以及毒力的丧失是 BSNP 采用的机制，使它们成为比化学合成物更好的抗真菌剂。随着抗药性的增加和真菌病原体在植物界的普遍存在，BSNP 有望成为新一代抗真菌药物。
