Interest in “green nanotechnology” in nanoparticle biosynthesis is growing among researchers. Nanotechnologies, due to their physicochemical and biological properties, have applications in diverse fields, including drug delivery, sensors, optoelectronics, and magnetic devices. This review focuses on the green synthesis of silver nanoparticles (AgNPs) using plant sources. Green synthesis of nanoparticles is an eco-friendly approach, which should be further explored for the potential of different plants to synthesize nanoparticles. The sizes of AgNPs are in the range of 1 to 100 nm. Characterization of synthesized nanoparticles is accomplished through UV spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and scanning electron microscopy. AgNPs have great potential to act as antimicrobial agents. The green synthesis of AgNPs can be efficiently applied for future engineering and medical concerns. Different types of cancers can be treated and/or controlled by phytonanotechnology. The present review provides a comprehensive survey of plant-mediated synthesis of AgNPs with specific focus on their applications, e.g., antimicrobial, antioxidant, and anticancer activities.

SUMMARYThe ectopic expression of a MADS box gene FOREVER YOUNG FLOWER (FYF) caused a significant delay of senescence and a deficiency of abscission in flowers of transgenic Arabidopsis. The defect in floral abscission was found to be due to a deficiency in the timing of cell separation of the abscission zone cells. Downregulation of INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) may contribute to the delay of the floral abscission in 35S:FYF flowers. FYF was found to be highly expressed in young flowers prior to pollination and was significantly decreased after pollination, a pattern that correlated with its function. Ethylene insensitivity in senescence/abscission and the down-regulation of ETHYLENE RESPONSE DNA-BINDING FACTOR 1 (EDF1) and EDF2, downstream genes in the ethylene response, in 35S:FYF Arabidopsis suggested a role for FYF in regulating senescence/abscission by suppressing the ethylene response. This role was further supported by the fact that 35S:FYF enhanced the delay of flower senescence/abscission in ethylene response 1 (etr1), ethylene-insensitive 2 (ein2) and constitutive triple response 1 (ctr1) mutants, which have defects in upstream genes of the ethylene signaling pathway. The presence of a repressor domain in the C-terminus of FYF and the enhancement of the delay of senescence/abscission in FYF+SRDX (containing a suppression motif) transgenic plants suggested that FYF acts as a repressor. Indeed, in FYF-DR+VP16 transgenic dominant-negative mutant plants, in which FYF was converted to a potent activator by fusion to a VP16-AD motif, the senescence/abscission of the flower organs was significantly promoted, and the expression of BOP2, IDA and EDF1/2 was up-regulated. Our data suggest a role for FYF in controlling floral senescence/abscission by repressing ethylene responses and regulating the expression of BOP2 and IDA in Arabidopsis.

Lycopene, belonging to the carotenoids, is a tetraterpene compound abundantly found in tomato and tomato-based products. It is fundamentally recognized as a potent antioxidant and a non-pro-vitamin A carotenoid. Lycopene has been found to be efficient in ameliorating cancer insurgences, diabetes mellitus, cardiac complications, oxidative stress-mediated malfunctions, inflammatory events, skin and bone diseases, hepatic, neural and reproductive disorders. This review summarizes information regarding its sources and uses amongst different societies, its biochemistry aspects, and the potential utilization of lycopene and possible mechanisms involved in alleviating the abovementioned disorders. Furthermore, future directions with the possible use of this nutraceutical against lifestyle-related disorders are emphasized. Its protective effects against recommended doses of toxic agents and toxicity and safety are also discussed.

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Bio-mediated synthesis of zinc oxide nanoparticles (ZnO NPs) was carried out by utilizing the reducing and capping potential of Andrographis paniculata leaf extract. The capped ZnO NPs were characterized using UV-Vis, XRD, FTIR, SEM, TEM and SAED analyses. FTIR analysis suggested the role of phenolic compounds, terpenoids, and proteins of A. paniculata leaf extract, in nucleation and stability of ZnO NPs. XRD pattern compared with the standard confirmed spectrum of zinc oxide particles formed in the present experiments were in the form of nanocrystals, as evidenced by the peaks at 2θ values. SEM and TEM analysis of ZnO NPs reveals those spherical and hexagonal shapes and the sizes at the range of 96-115 and 57 ± 0.3 nm, respectively. The synthesized nanoparticles possess strong biological activities regarding anti-oxidant, anti-diabetic, and anti-inflammatory potentials which could be utilized in various biological applications by the cosmetic, food and biomedical industries.

Recent advances in nanoscience and nanotechnology intend new and innovative applications in the food industry. Nanotechnology exposed to be an efficient method in many fields, particularly the food industry and the area of functional foods. Though as is the circumstance with the growth of any novel food processing technology, food packaging material, or food ingredient, additional studies are needed to demonstrate the potential benefits of nanotechnologies and engineered nanomaterials designed for use in foods without adverse health effects. Nanoemulsions display numerous advantages over conventional emulsions due to the small droplets size they contain: high optical clarity, excellent physical constancy against gravitational partition and droplet accumulation, and improved bioavailability of encapsulated materials, which make them suitable for food applications. Nano-encapsulation is the most significant favorable technologies having the possibility to ensnare bioactive chemicals. This review highlights the applications of current nanotechnology research in food technology and agriculture, including nanoemulsion, nanocomposites, nanosensors, nano-encapsulation, food packaging, and propose future developments in the developing field of agrifood nanotechnology. Also, an overview of nanostructured materials, and their current applications and future perspectives in food science are also presented.

Polygonum multiflorum Thunb. is a highly important medicinal plant producing anthraquinones (emodin and physcion) and phenolic compounds which has pharmaceutical use. In vitro seedling explants such as roots, internodals, nodals and leaves were inoculated with A. rhizogenes strain KCTC 2703. Transformed roots were induced from internodals and leaf explants. Six transgenic clones of hairy roots were established and confirmed by polymerase chain reaction (PCR) and reverse transcription-PCR (RT-PCR) using rolC specific primers. Hairy roots cultured using MS liquid medium supplemented with 30 g/l sucrose showed highest accumulation of biomass (99.05 g/l FW [fresh weight] and 10.95 g/l DW [dry weight]) and highest production of anthraquinones content (emodin 211.32 μg/g DW and physcion 353.23 μg/g DW) were observed at 20 days. Nearly 9.5-fold increment of biomass was evident in suspension cultures at 20 days of culture and hairy root biomass produced in suspension cultures possessed 3.7- and 3.5-fold higher content of emodin and physcion, respectively, when compared with the untransformed control roots. MS basal liquid medium was superior for the growth of hairy roots and production of anthraquinones compared with other culture media evaluated (SH, B5 and N6), with MS-basal liquid medium supplemented with 30 g/l sucrose was optimal for secondary metabolite production. A total of 23 polyphenolic compounds were identified and quantified from P. multiflorum untransformed and hairy roots, which includes hydroxybenzoic acids, hydroxycinnamic acids, flavonols and other groups of phenolic compounds. The ultra-performance liquid chromatography (UPLC) analysis of the phenolic compounds profile revealed that pyrogallol, hesperidin, naringenin and formononetin were higher in hairy roots compared to untransformed roots. The total phenolics, flavonoids content, antioxidant and antimicrobial activity was high in hairy roots compared to untransformed roots. This is the first report for the production of anthraquinones (emodin and physcion), phenolic compounds and biological activities from hairy root cultures of P. multiflorum.

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