Meloidogyne incognita (root-knot nematode) is a devastating soil-borne pathogen which can infect almost all cultivated plants around the globe, expediting huge pecuniary losses. The purpose of current study was to use the aqueous root extract of Glycyrrhiza glabra for synthesizing silver nanoparticles (GRAgNPs) and assess their nematicidal potential against M. incognita by in vitro methods, including hatching inhibition and mortality assays. The active uptake of FITC labeled GRAgNPs by the nematode and their effect on the expression of selected genes involved in oxidative stress and DNA damage repair were also studied. An HRTEM micrograph confirmed their spherical morphology with sizes ranging from 9.61 nm to 34.735 nm. Complete inhibition of egg-hatching was observed after 48 h of treatment with as low as 10.0 ppm of GRAgNPs. In addition, 100% mortality was recorded at the lowest dose of 6.0 ppm, after 12 h of treatment. The LC-50 for GRAgNPs was found to be 0.805 ± 0.177 ppm at p < 0.0001, R² = 0.9930, and α = 0.05. The expression of targeted genes (skn-1, mev-1, sod-3, dhs-23, cyp-450, xpa, cpr-1, gst-n, and ugt) was significantly enhanced (1.09–2.79 folds), at 1.0 ppm (α = 0.05, 95% CI) GRAgNPs treatment. In conclusion, GRAgNPs performed efficaciously and considerably in contrast to chemical nematicide and commercial silver nanoparticles (CAgNPs) and might be used as a promising alternative as relatively lower concentration and short exposure time were enough to cause higher mortality and nanotoxicity in nematodes.

Bio-fabrication of green or plant extract-based silver nanoparticles has garnered much praise over the past decade as the methodology is environment-friendly, undemanding, non-pathogenic, and economical. In the current study, leaves of Eurale ferox (Makhana), considered as waste, were used for the bio-fabrication of silver nanoparticles (ELAgNPs). Various analytical techniques including UV–VIS spectroscopy, Field emission scanning electron microscopy equipped with an energy dispersive X-ray spectrometer (FESEM-EDX), Particle size analyzer (PSA), Fourier transform infra-red spectroscopy (FTIR) and high-resolution transmission electron microscopy (HRTEM) were used for their characterization. Their antibacterial efficacy was examined against gram positive bacterium, Bacillus subtilis and gram negative bacterium, Escherichia coli. The antioxidant potential of the ELAgNPs was compassed by 2, 2 diphenyl-1-picryl hydrazyl (DPPH; λ_max = 517 nm) assay, H₂O₂ (λ_max = 230 nm) and OH⁻ (λ_max = 520 nm)-based radical scavenging assays. The cytotoxicity was checked against the VERO cell line using 3-[4, 5-dimethyl thiazol-2-yl]-2, 5 diphenyl tetrazolium bromide (MTT) assay. A mean particle size of 26.51 ± 8.87 nm with a size distribution of 7.08–53.94 nm was obtained using HRTEM. The ELAgNPs exhibited dose-dependent antibacterial efficacy with a maximum zone of inhibition (ZOI) of 21.98 ± 0.59 mm against B. subtilis and of 16.46 ± 0.22 mm against E. coli at 500 ppm after 24 h of incubation. The median lethal concentration for the cytotoxicity analysis was found to be 9.54 ± 0.35 ppm, 120.9 ± 6.31 ppm, and 20.74 ± 0.63 ppm for ELAgNPs, commercial silver nanoparticles (CAgNPs), and silver nitrate (SN), respectively. The ordinary one-way ANOVA results exhibited a significant decrease in cell viability after 72 h of incubation at p < 0.05, α = 0.05. In conclusion, the ELAgNPs showed good antibacterial, radical scavenging and dose-dependent cytotoxicity against the VERO cells. Therefore, these could be used for biomedical applications. Phyto-constituents present in the plant not only act as reducing agents but also as stabilizing and coating agents, and the availability of a wide range of metabolites makes the green approach more promising.

Crop improvement under changing climatic conditions is required to feed the growing global population. The development of transgenic crops is an attractive and conceivably the most effective approach for crop improvement with desired traits in varying climatic situations. Here, we describe a simple, efficient and robust in planta Agrobacterium-mediated genetic transformation method that can be used in most crops, including rice, wheat and cotton, and particularly in tissue culture recalcitrant crops, such as chickpea and pigeon pea. The protocol was successfully used for the development of transgenic chickpea and pigeon pea lines for resistance against pod borer. Transgenic lines in chickpea, pigeon pea and wheat were also developed for salt stress tolerance. These lines exhibited improved salt tolerance in terms of various physio-biochemical parameters studied. Since the protocol is rapid, as no tissue culture step is involved, it will significantly contribute to the improvement of most crops and will be of interest for plant biologists working with genetic engineering or genome editing.