Antifungal Activity of Green and Chemically Synthesized ZnO Nanoparticles against Alternaria citri, the Causal Agent Citrus Black Rot

Abstract

Citrus black rot is a serious disease of citrus plants caused by <i>Alternaria citri</i>. The current study aimed to synthesize zinc oxide nanoparticles (ZnO-NPs) by chemically or green method and investigate their antifungal activity against <i>A. citri</i>. The sizes of synthesized as measured by transmission electron microscope of ZnO-NPs were 88 and 65 nm for chemical and green methods, respectively. The studied prepared ZnO-NPs were applied, <i>in vitro</i> and <i>in situ</i>, at different concentrations (500, 1,000, and 2,000 µg/ml) in post-harvest treatment on navel orange fruits to verify the possible control effect against <i>A. citri</i>. Results of <i>in vitro</i> assay demonstrated that, at concentration 2,000 µg/ml, the green ZnO-NPs was able to inhibit about 61% of the fungal growth followed by 52% of chemical ZnO-NPs. In addition, scanning electron microscopy of <i>A. citri</i> treated <i>in vitro</i> with green ZnO-NPs showed swelling and deformation of conidia. Results showed also that, using a chemically and green ZnO-NPs at 2,000 µg/ml <i>in situ</i> in post-harvest treatment of orange, artificially-infected with <i>A. citri</i>, has reduced the disease severity to 6.92% and 9.23%, respectively, compared to 23.84% of positive control (non-treated fruits) after 20 days of storage. The out findings of this study may contribute to the development of a natural, effective, and eco-friendly strategy for eradicating harmful phytopathogenic fungi.

Green Synthesis of Zinc Oxide Nanoparticles Using Aqueous Extracts of Hibiscus cannabinus L.: Wastewater Purification and Antibacterial Activity

“…Dangana et al prepared ZnO nanoparticles using extracts obtained from the leaves of Chaya Cnidoscolus aconitifolius and used them as nano fertilizers on Sorghum bicolour plants [9]. Elshafie et al carried out the green synthesis of ZnO nanoparticles using Moringa oleifera leaves [10]. Rini et al reported a green method of synthesizing ZnO nanoparticles using pineapple-peel extract and evaluated their antibacterial activity [11].…”

Biosynthesis of zinc oxide nanoparticles via neem extract and their anticancer and antibacterial activities

“…The stock solution was stored in the refrigerator at 4 °C. This solution was also used for the investigation of neem phytochemistry ( Elumalai et al, 2012 ; El-Saber, 2021 ; Elshafie et al, 2023 ).…”

“…The particles obtained were subjected to centrifugation, and the resulting solid masses were gathered. The pellet was dried and calcined at 300 °C for 2 h. The process was followed to obtain white colored nanoparticles ( Pal et al, 2018 ; Zambri et al, 2019 ; El-Saber, 2021 ; Elshafie et al, 2023 ).…”

Photo-catalytic and biological applications of phyto-functionalized zinc oxide nanoparticles synthesized using a polar extract of Equisetum diffusum D

“…20 ZnO NPs have found several uses in various fields, including catalysis, antioxidant activity, environmental protection, electronics, cosmetics, communication, biology, and pharmaceutical industries. 21–23 Furthermore, due to their antimicrobial, 24 antifungal, 25 anti-diabetic, 26 and insecticidal 27 features, ZnO NPs have a vast variety of medical utilities that include bio-sensing, 28 drug transport, 29 and nanomedicines. 30 The use of different parts of plant extracts is a promising technique for the synthesis of ZnO NPs.…”