Comprehensive antifungal investigation of green synthesized silver nanoformulation against four agriculturally significant fungi and its cytotoxic applications.

The present study reports the green synthesis of silver nanoparticles (AgNPs) in powder form using the leaf extract of Azadirachta indica. The synthesis of AgNPs was confirmed by UV-vis spectroscopy, FTIR, XRD, FESEM, and EDX. The synthesized AgNPs were in a powdered state and dispersed completely in 5% polyethylene glycol (PEG) and demonstrated prolonged shelf life and enhanced bioavailability over a year without any aggregation. The resulting silver nanoformulation demonstrated complete inhibition against Sclerotinia sclerotiorum and Colletotrichum falcatum and 68% to 80% inhibition against Colletotrichum gloeosporioides and Rhizoctonia solani respectively, at 2000 ppm. The EC50 values determined through a statistical analysis were 66.42, 157.7, 19.06, and 33.30 ppm for S. sclerotiorum, C. falcatum, C. gloeosporioides, and R. solani respectively. The silver nanoformulation also established significant cytotoxicity, with a 74.96% inhibition rate against the human glioblastoma cell line U87MG at 250 ppm. The IC50 value for the cancerous cell lines was determined to be 56.87 ppm through statistical analysis. The proposed silver nanoformulation may be used as a next-generation fungicide in crop improvement and may also find application in anticancer investigations. To the best of our knowledge, this is also the first report of silver nanoformulation demonstrating complete inhibition against the economically significant phytopathogen C. falcatum.

Metal nanoparticles to improve the heat resilience in wheat (Triticum aestivumL.).

This study evaluated the efficacy of phytogenic silver and zinc nanoparticles in improving heat resilience in various wheat varieties. The silver and zinc nanoparticles were synthesized using plant leaf extract and characterized using various techniques. Four wheat varieties (DBW187, Black Wheat, DBW 50, and PBW 621) were subjected to field trials. The random block design was used, and nanoparticles in different concentrations were applied at various growth stages and morphologically, and yield parameters were recorded. UV-vis spectroscopy spectral analysis showed peaks for Ag nanoparticles at 420 nm wavelength and Zn nanoparticles at 240 and 350 nm wavelength, depicting the preliminary confirmation of nanoparticle synthesis. Electron microscopic analysis (TEM and SEM) provided morphological insights and confirmed synthesis of fine-sized particle mostly in a range between 10 and 60 nm. Energy dispersive x-ray analysis confirmed the elemental composition of the synthesized nanoparticles, with Ag and Zn elements detected in their respective samples. It also confirmed the oxide nature of synthesized ZnNPs. Dynamic light scattering analysis provided size distribution profiles, indicating average sizes of approximately 61.8 nm for Ag nanoparticles and 46.5 nm for Zn nanoparticles. The concentrations of Ag and Zn nanoparticles in the samples were found to be 196.3 ppm and 115.14 ppm, respectively, through atomic absorption spectroscopic analysis. Fourier transform infrared spectroscopy analysis revealed characteristic functional groups present in the nanoparticles. The results of field experiments established that Ag nanoparticles at 75 ppm concentration exhibited the most significant enhancements in plant growth. Conversely, Zn nanoparticles at a 100 ppm concentration demonstrated the most substantial improvements in the growth and yield of heat-stressed wheat varieties. The study concludes that optimized concentrations of silver and zinc nanoparticles can effectively improve heat stress resilience in wheat. These findings are promising to enhance abiotic stress resilience in crops.

Evaluation of efficacy of Phyto-synthesized iron oxide nanoparticles in contributing drought resilience in wheat (Triticum aestivumL.).

Wheat is the majorly cultivated staple crop worldwide. The world witnesses a great percentage of yield loss of wheat due to drought stress. The present study aimed at evaluating the efficacy of phytosynthesized iron oxide nanoparticles (FeONPs) in contributing to drought resilience in wheat (Triticum aestivumL.) under rain-fed conditions. FeONPs were biosynthesized by using leaf extract ofProsopis cinerariaas a reducing and capping agent. The synthesized nanoparticles were characterized to evaluate the structural and biochemical aspects. The FeONPs were found to be irregularly spherical in shape with a mean size of 42.6 nm. The concentration of nanoparticles in the sample was found to be 164.01 mg l-1. An experimental setup was laid out in a randomized-plot design with 3 replications for Rabi season 2020-2021. Five dosages of nanoparticles were prepared as 12.5, 25, 50, 75 and 100 ppm from the stock solution. The wheat crop varieties grown in the field were subjected to a total of 3 treatments; Nanopriming, foliar application of FeONPs at seedling development stage (20 DAS), and tillering stage (30 DAS). Plants that were not treated with NPs were considered as control. No irrigation regime was followed as the effect of NPs on the crop was to be assessed under rain-fed conditions only. Plant growth parameters were recorded. The obtained results revealed that the application of FeONPs positively affected all the morphological and yield attributes in the wheat crop. The highest concentrations used were found to be most effective and showed a significantly pronounced effect as compared to the control atp≤ 0.05. The study concluded that the FeONPs can contribute to drought resilience in wheat.