Bio-fabrication of Zinc Oxide nanoparticles to rescue Mung Bean against Cercospora leaf spot disease

Harnessing Walnut-Based Zinc Oxide Nanoparticles: A Sustainable Approach to Combat the Disease Complex of Meloidogyne arenaria and Macrophomina phaseolina in Cowpea

Zinc oxide nanoparticles (ZnO NPs) exhibit diverse applications, including antimicrobial, UV-blocking, and catalytic properties, due to their unique structure and properties. This study focused on the characterization of zinc oxide nanoparticles (ZnO NPs) synthesized from Juglans regia leaves and their application in mitigating the impact of simultaneous infection by Meloidogyne arenaria (root-knot nematode) and Macrophomina phaseolina (root-rot fungus) in cowpea plants. The characterization of ZnO NPs was carried out through various analytical techniques, including UV-visible spectrophotometry, Powder-XRD analysis, FT-IR spectroscopy, and SEM-EDX analysis. The study confirmed the successful synthesis of ZnO NPs with a hexagonal wurtzite structure and exceptional purity. Under in vitro conditions, ZnO NPs exhibited significant nematicidal and antifungal activities. The mortality of M. arenaria juveniles increased with rising ZnO NP concentrations, and a similar trend was observed in the inhibition of M. phaseolina mycelial growth. SEM studies revealed physical damage to nematodes and structural distortions in fungal hyphae due to ZnO NP treatment. In infected cowpea plants, ZnO NPs significantly improved plant growth parameters, including plant length, fresh mass, and dry mass, especially at higher concentrations. Leghemoglobin content and the number of root nodules also increased after ZnO NP treatment. Additionally, ZnO NPs reduced gall formation and egg mass production by M. arenaria nematodes and effectively inhibited the growth of M. phaseolina in the roots. Furthermore, histochemical analyses demonstrated a reduction in oxidative stress, as indicated by decreased levels of reactive oxygen species (ROS) and lipid peroxidation in ZnO NP-treated plants. These findings highlight the potential of green-synthesized ZnO NPs as an eco-friendly and effective solution to manage disease complex in cowpea caused by simultaneous nematode and fungal infections.

Unveiling the Potential of Bioinoculants and Nanoparticles in Sustainable Agriculture for Enhanced Plant Growth and Food Security

The increasing public concern over the negative impacts of chemical fertilizers and pesticides on food security and sustainability has led to exploring innovative methods that offer both environmental and agricultural benefits. One such innovative approach is using plant-growth-promoting bioinoculants that involve bacteria, fungi, and algae. These living microorganisms are applied to soil, seeds, or plant surfaces and can enhance plant development by increasing nutrient availability and defense against plant pathogens. However, the application of biofertilizers in the field faced many challenges and required conjunction with innovative delivering approaches. Nanotechnology has gained significant attention in recent years due to its numerous applications in various fields, such as medicine, drug development, catalysis, energy, and materials. Nanoparticles with small sizes and large surface areas (1-100 nm) have numerous potential functions. In sustainable agriculture, the development of nanochemicals has shown promise as agents for plant growth, fertilizers, and pesticides. The use of nanomaterials is being considered as a solution to control plant pests, including insects, fungi, and weeds. In the food industry, nanoparticles are used as antimicrobial agents in food packaging, with silver nanomaterials being particularly interesting. However, many nanoparticles (Ag, Fe, Cu, Si, Al, Zn, ZnO, TiO2, CeO2, Al2O3, and carbon nanotubes) have been reported to negatively affect plant growth. This review focuses on the effects of nanoparticles on beneficial plant bacteria and their ability to promote plant growth. Implementing novel sustainable strategies in agriculture, biofertilizers, and nanoparticles could be a promising solution to achieve sustainable food production while reducing the negative environmental impacts.

Foliar Spraying of ZnO Nanoparticles Enhanced the Yield, Quality, and Zinc Enrichment of Rice Grains

Zinc deficiency in rice can lead to reduced nutritional value and taste. This study investigates the potential of zinc oxide nanoparticles (ZnO NPs) as a foliar fertilizer during the jointing stage to improve rice yield, quality, and grain zinc enrichment. Over a two-year field experiment (2019-2020), six doses of ZnO NPs (ranging from 0 to 12 kg hm-2) were applied during the jointing stage (46 days after transplanting). The results revealed that foliar spraying of ZnO NPs increased the number of spikelets per spike and the thousand-grain weight by 7.4% to 9.2% and 4.2% to 7.1%, respectively, resulting in a substantial increase in rice yield. Furthermore, it led to a reduction in chalky white and chalky whiteness by 6.23% to 23.6% and 2.2% to 27.9%. ZnO NPs effectively boosted zinc content in rice grains while decreasing the phytic acid to zinc ratio, indicating improved zinc enrichment. Remarkably, protein and amylose content remained unaffected. These findings underscore the potential of ZnO NPs as a foliar fertilizer to enhance rice production, quality, and zinc enrichment. Further research can explore optimal application strategies and long-term effects for sustainable rice production.