Antifungal Activity of Copper Oxide Nanoparticles against Root Rot Disease in Cucumber

Said M Kamel; Samah F Elgobashy; Reda I Omara; Aly S Derbalah; Mahmoud Abdelfatah; Abdelhamed El-Shaer; Abdulaziz A Al-Askar; Ahmed Abdelkhalek; Kamel A Abd-Elsalam; Tarek Essa; Muhammad Kamran; Mohsen Mohamed Elsharkawy

doi:10.3390/jof8090911

Antifungal Activity of Copper Oxide Nanoparticles against Root Rot Disease in Cucumber

J Fungi (Basel). 2022 Aug 28;8(9):911. doi: 10.3390/jof8090911.

Affiliations

¹ Plant Pathology Research Institute, Agricultural Research Center, Giza 12619, Egypt.
² Pesticides Chemistry and Toxicology Department, Faculty of Agriculture, Kafrelsheikh University, Kafr el-Sheikh 33516, Egypt.
³ Physics Department, Faculty of Science, Kafrelsheikh University, Kafr el-Sheikh 33516, Egypt.
⁴ Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.
⁵ Plant Protection and Biomolecular Diagnosis Department, ALCRI, City of Scientific Research and Technological Applications, New Borg ElArab City 21934, Egypt.
⁶ School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, SA 5005, Australia.
⁷ Agricultural Botany Department, Faculty of Agriculture, Kafrelsheikh University, Kafr el-Sheikh 33516, Egypt.

Abstract

Metal oxide nanoparticles have recently garnered interest as potentially valuable substances for the management of plant diseases. Copper oxide nanoparticles (Cu₂ONPs) were chemically fabricated to control root rot disease in cucumbers. A scanning electron microscope (SEM), X-ray diffraction (XRD) and photoluminescence (PL) were employed to characterize the produced nanoparticles. Moreover, the direct antifungal activity of Cu₂ONPs against Fusarium solani under laboratory, greenhouse, and field conditions were also evaluated. In addition, the induction of host-plant resistance by Cu₂ONPs was confirmed by the results of enzyme activities (catalase, peroxidase, and polyphenoloxidase) and gene expression (PR-1 and LOX-1). Finally, the effect of Cu₂ONPs on the growth and productivity characteristics of the treated cucumber plants was investigated. The average particle size from all the peaks was found to be around 25.54 and 25.83 nm for 0.30 and 0.35 Cu₂O, respectively. Under laboratory conditions, the study found that Cu₂ONPs had a greater inhibitory effect on the growth of Fusarium solani than the untreated control. Cu₂ONP treatment considerably reduced the disease incidence of the root rot pathogen in cucumber plants in both greenhouse and field environments. Defense enzyme activity and defense genes (PR1 and LOX1) transcription levels were higher in cucumber plants treated with Cu₂ONPs and fungicide than in the untreated control. SEM analysis revealed irregularities, changes, twisting, and plasmolysis in the mycelia, as well as spore shrinking and collapsing in F. solani treated with Cu₂ONPs, compared to the untreated control. The anatomical analysis revealed that cucumber plants treated with Cu₂ONPs had thicker cell walls, root cortex, and mesophyll tissue (MT) than untreated plants. Cucumber growth and yield characteristics were greatly improved after treatment with Cu₂ONPs and fungicide. To the best of our knowledge, employing Cu₂ONPs to treat cucumber rot root disease is a novel strategy that has not yet been reported.

Keywords: Fusarium solani; anatomical structure; control; defense genes; enzymes; metal oxide nanoparticles; resistance; scanning electron microscope.

Grants and funding

RSP2022R505/This research was financially supported by the Researchers Supporting Project number (RSP2022R505), King Saud University, Riyadh, Saudi Arabia.