The immunomodulatory role of the natural biopolymer, chitosan, has already been demonstrated in plants, whilst its nanoparticles have only been examined for biomedical applications. In our present study, we have investigated the possible ability and mechanism of chitosan nanoparticles (CNP) to induce and augment immune responses in plants. CNP-treatment of leaves produced significant improvement in the plant’s innate immune response through induction of defense enzyme activity, upregulation of defense related genes including that of several antioxidant enzymes as well as elevation of the levels of total phenolics. It is also possible that the extracellular localization of CNP may also play a role in the observed upregulation of defense response in plants. Nitric oxide (NO), an important signaling molecule in plant defense, was also observed to increase following CNP treatment. However, such CNP-mediated immuno-stimulation was significantly mitigated when NO production was inhibited, indicating a possible role of NO in such immune induction. Taken together, our results suggest that CNP may be used as a more effective phytosanitary or disease control agent compared to natural chitosan for sustainable organic cultivation.

Copper and Copper oxide nanoparticles have garnered a lot of attention among the metal oxide nanoparticles, especially because of their many characteristics and applications in many disciplines, notably nanomedicine and biomedical sciences. We have covered all of the conceivable green production techniques of copper/copper oxide nanoparticles in this review. This manuscript also diagrammatically depicts the exact mechanism of all conceivable biosynthetic routes. We also look at the antibacterial, antifungal, antiviral, and anticancer properties of biosynthesized copper/copper oxide nanoparticles, as well as their effects on plant growth, nutrition, and defense mechanism. GRAPHICAL ABSTRACT

Biosynthesis of copper oxide nanoparticles (CuONPs) in a cost-effective and eco-friendly way has gained its importance. CuONPs has been prepared from copper sulfate by using Adiantum lunulatum whole plant extract. CuONPs have been characterized by X-ray diffraction, Fourier transform infrared spectroscopic, transmission electron microscope, etc. Mono-disperse, spherical, pure, and highly stable CuONPs have formed with an average diameter of 6.5 ± 1.5 nm. Biosynthesized CuONPs at different concentrations were applied to seeds of Lens culinaris. Physiological characteristics were investigated in the germinated seeds. Roots obtained from the seeds treated with 0.025 mgmL⁻¹ concentration of CuONPs showed highest activity of different defence enzymes and total phenolics. However, at higher concentration it becomes close to control. It showed gradual increase of antioxidative enzymes, in accordance with the increasing dose of CuONPs. Likewise, lipid peroxidation and proline content gradually increased with the increasing concentration. Reactive oxygen species and nitric oxide generation was also altered due to CuONPs treatment indicating stress signal transduction. Finally, this study provides a new approach of the production of valuable CuONPs, is a unique, economical, and handy tool for large scale saleable production which can also be used as a potent plant defence booster instead of other commercial uses.

Biopesticides are formulations derived from naturally occurring compounds that manage pests through non-toxic and environmentally favorable means. Being living organisms (natural enemies) or products, biopesticides represent less of a risk to the environment and to human health. Biopesticides, classified into three broad classes, are increasingly used in pest control, and include semiochemicals, plant-incorporated protectants (PIPs), and compounds derived from plants and microorganisms. Because of their advantages for the environment, target-specificity, efficacy, biodegradability, and applicability in integrated pest management (IPM) programs, biopesticides are gaining interest. Although biopesticides have seen significant advances in market penetration, they still make up a relatively small fraction of pest management solutions. Over 3000 tons are produced globally per annum, and this number is rising rapidly. In India, biopesticides account for just 4.2% of the country’s total pesticide market. Although the government has promoted the use of biopesticides by including them in several agricultural programs, biopesticides face numerous difficulties at a local level, but are predicted to expand at an astonishing 10% yearly pace. Under the Insecticides Act 1968, the Ministry of Agriculture in India controls the use of pesticides. Among the major biopesticides produced and used in India are Trichoderma, Bacillus thuringiensis, nuclear polyhedrosis virus, and neem-based pesticides.