Ginger Essential Oils-Loaded Nanoemulsions: Potential Strategy to Manage Bacterial Leaf Blight Disease and Enhanced Rice Yield

Abstract

The bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most serious rice diseases, causing huge yield losses worldwide. Several technologies and approaches have been opted to reduce the damage; however, these have had limited success. Recently, scientists have been focusing their efforts on developing efficient and environmentally friendly nanobactericides for controlling bacterial diseases in rice fields. In the present study, a scanning electron microscope (SEM), transmission electron microscope (TEM), and a confocal laser scanning microscope (CLSM) were utilized to investigate the mode of actions of ginger EOs on the cell structure of Xoo. The ginger EOs caused the cells to grow abnormally, resulting in an irregular form with hollow layers, whereas the dimethylsulfoxide (DMSO) treatment showed a typical rod shape for the Xoo cell. Ginger EOs restricted the growth and production of biofilms by reducing the number of biofilms generated as indicated by CLSM. Due to the instability, poor solubility, and durability of ginger EOs, a nanoemulsions approach was used, and a glasshouse trial was performed to assess their efficacy on BLB disease control. The in vitro antibacterial activity of the developed nanobactericides was promising at different concentration (50–125 µL/mL) tested. The efficacy was concentration-dependent. There was significant antibacterial activity recorded at higher concentrations. A glasshouse trial revealed that developed nanobactericides managed to suppress BLB disease severity effectively. Treatment at a concentration of 125 μL/mL was the best based on the suppression of disease severity index, AUDPC value, disease reduction (DR), and protection index (PI). Furthermore, findings on plant growth, physiological features, and yield parameters were significantly enhanced compared to the positive control treatment. In conclusion, the results indicated that ginger essential oils loaded-nanoemulsions are a promising alternative to synthetic antibiotics in suppressing Xoo growth, regulating the BLB disease, and enhancing rice yield under a glasshouse trial.

Trends in Nanotechnology and Its Potentialities to Control Plant Pathogenic Fungi: A Review

“…The decrease to the nanometric scale of the drop size could increase the zone of the substrate which then creates contact with the fungal pathogen to bring about cell death and lysis. The constituents of EOs can get to the pathways of the cell membrane due to their surface-to-volume proportions, physical characteristics, sizes, degrees of selectivity, and chemical stabilities, consequently setting the movement of EOs to arrive at their target areas [115]. The encapsulation innovations and controlled techniques for discharge have changed the utilization of nanotechnology-based ginger EOs as an antifungal and antibacterial for the conservation of different crops [121].…”

“…The delivery system of Eos, such as microemulsions, nanoemulsions, liposomes, and solid lipid nanoparticles, are designed for enclosing different compounds (natural bioactive) to improve antifungal efficacy [ 115 , 116 ]. Nanoemulsion is the dispersal of nanoparticles comprising of two different fluids that are insoluble, specifically water and oil, one of which is dispersed by a surfactant, as presented in Figure 3 .…”

Effectiveness of oil-based nanoemulsions with molecular docking of its antimicrobial potential

“…For example, NEs of ginger oils suppress the growth of Xanthomonas oryzae pv. oryzae (Xoo), which is the causative agent of leaf blight in rice (Adamu et al 2021). NEs of thyme and carvacrol oils were applied as antifungal treatments against Aspergillus fumigatus, causing alterations in the structure of conidia and fungal hyphae (Hassanien et al 2021).…”

Phytochemicals Profiling, Antimicrobial Activity and Mechanism of Action of Essential Oil Extracted from Ginger (Zingiber officinale Roscoe cv. Bentong) against Burkholderia glumae Causative Agent of Bacterial Panicle Blight Disease of Rice

“…Scanning electron microscope studies were carried out to observe the morphological deviations of Bg treated with GEO, as described by de Oliveira et al, (2011) [ 48 , 49 ] with few adjustments. An SEM study was performed at the microscopy unit, Institute of Bioscience (IBS), UPM.…”