Effect of green synthesised silver nanoparticles on morphogenic and biochemical variations in callus cultures of kinnow mandarin (Citrus reticulata L.)

Biosynthesized silver nanoparticles enhanced wheat resistance to Bipolaris sorokiniana

Agronomic crops can benefit from the application of nanoscale materials in order to control phytopathogens and improve plant growth. Bipolaris sorokiniana, a soil- and seed-borne fungus, causes severe yield losses in wheat. In order to determine the physio-chemical changes in wheat under biotic stress of B. sorokiniana, the current study aimed to synthesis silver nanoparticles (AgNPs) using Allium sativum bulb extract. Herein, we applied the silver nanoparticles (AgNPs) as a foliar spray on two wheat varieties (Pakistan-2013, and NARC-2011) at the concentrations of 10, 20, 30, and 40 mg/L to suppress B. sorokiniana. Among all the applied concentrations of AgNPs, the 40 mg/L concentration demonstrated the most effective outcome in reduction of the intensity of spot blotch and improved the morphological, physiological, biochemical parameters, as well as antioxidant activity in wheat plant. Foliar application of AgNPs at 40 mg/L Pakistan-2013 and NARC-2011 wheat varieties significantly increased chlorophyll a 84.8% and 53.4%, chlorophyll b 28.9% and 84.3%, total chlorophyll content 294.3% and 241.2%, membrane stability index 7.5% and 6.1%, relative water contents 25.4% and 10.5%, proline content 320.5% and 609.9%, and soluble sugar content 120% and 259.4%, respectively, compared to control and diseased plant. This is the first study provides important insights into the role of phyto-mediated AgNPs in increasing resistant of wheat infected with B. sorokiniana. These findings offers valuable new insights that may be useful for reducing disease incidence in wheat fields.

Responses of Medicinal and Aromatic Plants to Engineered Nanoparticles

Medicinal and aromatic plants have been used by mankind since ancient times. This is primarily due to their healing effects associated with their specific secondary metabolites (some of which are also used as drugs in modern medicine), or their structures, served as a basis for the development of new effective synthetic drugs. One way to increase the production of these secondary metabolites is to use nanoparticles that act as elicitors. However, depending on the specific particle size, composition, concentration, and route of application, nanoparticles may have several other benefits on medicinal and aromatic plants (e.g., increased plant growth, improved photosynthesis, and overall performance). On the other hand, particularly at applications of high concentrations, they are able to damage plants mechanically, adversely affect morphological and biochemical characteristics of plants, and show cytotoxic and genotoxic effects. This paper provides a comprehensive overview of the beneficial and adverse effects of metal-, metalloid-, and carbon-based nanoparticles on the germination, growth, and biochemical characteristics of a wide range of medicinal and aromatic plants, including the corresponding mechanisms of action. The positive impact of nanopriming and application of nanosized fertilizers on medicinal and aromatic plants is emphasized. Special attention is paid to the effects of various nanoparticles on the production of valuable secondary metabolites in these plants cultivated in hydroponic systems, soil, hairy root, or in vitro cultures. The beneficial impact of nanoparticles on the alleviation of abiotic stresses in medicinal and aromatic plants is also discussed.

Silver nanoparticles and silver salt (AgNO3) elicits morphogenic and biochemical variations in callus cultures of sugarcane

The research work was arranged to check the role of AgNPs and silver ions on callus cells of sugarcane (Saccharum spp. cv CP-77,400). AgNPs were synthesized chemically and characterized by UV-Vis spectra, XRD and SEM. AgNPs and silver ions were applied in various concentrations (0, 20, 40, 60 ppm) to sugarcane calli and the induced stress was characterized by studying various morphological and biochemical parameters. AgNPs and silver ions treatments produced high levels of malondialdehyde, proline, proteins, TP and TF contents. Similarly, CAT, SOD and POX activity was also significant in both treatments. The lower concentration of AgNPs and silver ions (20 ppm) provided maximum intracellular GSH level. This work mainly showed effects of AgNPs and silver ions on sugarcane calli in terms of morphological aberrations and cell membrane damage due to severe oxidative stress and production of enhanced levels of enzymatic and non-enzymatic antioxidants as self-defence to tolerate oxidative stress by scavenging reactive oxygen species. These preliminary findings will provide the way to study ecotoxicity mechanism of the metal ions and NPs in medicine industry and in vitro toxicity research. Furthermore, silver ions alone and their chemically synthesised AgNPs can be used for various biomedical applications in future.