Influence of the capping of biogenic silver nanoparticles on their toxicity and mechanism of action towards Sclerotinia sclerotiorum

Abstract

Background Biogenic nanoparticles possess a capping of biomolecules derived from the organism employed in the synthesis, which contributes to their stability and biological activity. These nanoparticles have been highlighted for the control of phytopathogens, so there is a need to understand their composition, mechanisms of action, and toxicity. This study aimed to investigate the importance of the capping and compare the effects of capped and uncapped biogenic silver nanoparticles synthesized using the filtrate of Trichoderma harzianum against the phytopathogenic fungus Sclerotinia sclerotiorum. Capping removal, investigation of the composition of the capping and physico-chemical characterization of the capped and uncapped nanoparticles were performed. The effects of the nanoparticles on S. sclerotiorum were evaluated in vitro. Cytotoxicity and genotoxicity of the nanoparticles on different cell lines and its effects on nontarget microorganisms were also investigated. Results The capped and uncapped nanoparticles showed spherical morphology, with greater diameter of the uncapped ones. Functional groups of biomolecules, protein bands and the hydrolytic enzymes NAGase, β-1,3-glucanase, chitinase and acid protease from T. harzianum were detected in the capping. The capped nanoparticles showed great inhibitory potential against S. sclerotiorum, while the uncapped nanoparticles were ineffective. There was no difference in cytotoxicity comparing capped and uncapped nanoparticles, however higher genotoxicity of the uncapped nanoparticles was observed towards the cell lines. Regarding the effects on nontarget microorganisms, in the minimal inhibitory concentration assay only the capped nanoparticles inhibited microorganisms of agricultural importance, while in the molecular analysis of the soil microbiota there were major changes in the soils exposed to the uncapped nanoparticles. Conclusions The results suggest that the capping played an important role in controlling nanoparticle size and contributed to the biological activity of the nanoparticles against S. sclerotiorum. This study opens perspectives for investigations concerning the application of these nanoparticles for the control of phytopathogens.

Influence of Polyvinylpyrrolidone Concentration on Properties and Anti-Bacterial Activity of Green Synthesized Silver Nanoparticles

“…To the best of our knowledge, there is no similar results have been reported earlier in the literatures [ 36 , 37 ]. This result support the benefit of coated silver nanoparticles with PVP to control the release ratio of silver ions and reduce the toxicity effect of AgNPs against living cells especially for medical and pharmacology applications as drug delivery systems and wound healing without any side effects [ 38 ]. The green synthesized AgNPs were characterized using various analyses such as UV–Vis spectrophotometry, scanning electron microscopy (SEM), energy dispersive spectrum (EDX), fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and nano tracker analysis (NTA).…”

Green Synthesized Silver Nanoparticles: Antibacterial and Anticancer Activities, Biocompatibility, and Analyses of Surface-Attached Proteins

“…Further studies revealed the presence of other proteins of an enzymatic nature, namely acid phosphatase (EC 3.1.3.2), glucoamylase (1,4-α-D-glucanglucohydrolase, EC 3.2.1.3), glucanosyltransferase (EC 2.4), and serine carboxypeptidase (EC 3.4.21.26), which were associated with AgNPs by electrostatic and additional protein-protein interactions and responsible for the metabolic activities of A. tubingensis (Ballottin et al, 2016). More recently, Guilger-Casagrande et al (2021) studied the significance of capping agents of AgNPs synthesized from Trichoderma harzianum and compared with AgNPs without caps. Interestingly, the capped AgNPs demonstrated remarkable inhibition of Sclerotinia sclerotiorum, a plant pathogen.…”

Effects of biogenic silver and iron nanoparticles on soybean seedlings (Glycine max)

“…The need to investigate the possible effects of biogenic metallic nanoparticles on plants is emerging due to the potential that these new materials have been presenting for the control of phytopathogens which cause significant agricultural losses [ 10 , 27 , 56 ]. In addition, biogenic nanoparticles have a capping that confers unique characteristics, influencing their toxicity [ 9 ].…”