Overexpression of AtMYB12 transcription factor simultaneously enhances quercetin-dependent metabolites in radish callus

The study aimed to enhance quercetin production in radish by optimizing Agrobacterium tumefaciens-mediated in-planta transformation. This protocol involved infecting radish seed embryo axis with A. tumefaciens EHA105 strain carrying the 35S::AtMYB12. Radish seeds were infected with the Agrobacterium suspension (0.8 OD600) for 30 min, followed by sonication for 60 s and vacuum infiltration for 90 s at 100 mm Hg. A 3-day co-cultivation in Murashige and Skoog medium with 150 μM acetosyringone yielded a transformation efficiency of 59.6% and a transgenic callus induction rate of 32.3%. Transgenic plant and callus lines were confirmed by GUS histochemical assay, PCR, and qRT-PCR. The transgenic lines showed an increased expression of flavonoid pathway genes (AtMYB12, CHS, F3H, and FLS) and antioxidant genes (GPX, APX, CAT, and SOD) compared to WT plants. Overexpression of AtMYB12 in transgenic callus increased enzyme activity of phenylalanine ammonia lyase, catalase, and ascorbate peroxidase. In half-strength MS medium with 116.8 mM sucrose, the highest growth index (7.63) was achieved after 20 days. In AtMYB12 overexpressed callus lines, phenolic content (357.31 mg g−1 dry weight), flavonoid content (463 mg g−1 dry weight), and quercetin content (48.24 mg g−1 dry weight) increased significantly by 9.41-fold. Micro-wounding, sonication, and vacuum infiltration improved in-planta transformation in radishes. These high-quercetin-content transgenic callus lines hold promise as valuable sources of flavonoids

Can Ocimum basilicum L. and Ocimum tenuiflorum L. in vitro culture be a potential source of secondary metabolites?

In this study Ocimum basilicum L. (OB) and Ocimum tenuiflorum L. (OT) in vitro culture standardisation for increasing eugenol distribution, in comparison to their respective field grown parts was carried out. Eugenol was quantified using an optimised HPLC method and its relation with the total phenolic content (TPC) was measured. In vitro grown leaves and somatic embryos, of both OB and OT were found to contain similar quantities of eugenol (85 μg/g approximately), higher than OB and OT field-grown leaves (30.2 μg/g and 25.1 μg/g respectively). It was also determined that in vitro grown leaves were richer in TPC than the field-grown intact organs. Results demonstrated the prominence of in vitro cultures for eugenol extraction. This study underlines that important food flavouring metabolites (e.g. vanillin, vanillic acids) might be produced, via the eugenol pathway, in Ocimum species that may be a good potential source of eugenol

The Implementation of HIV Self-Testing in Resource-Limited Settings Where the HIV Disease Burden is High

In resource-limited settings, there is growing evidence that HIV testing is lacking among high-risk key populations such as men having sex with men, injection drug users, and transgenders largely due to stigma, discrimination, and lack of confidentiality. Findings from recent studies among high-risk key populations and the general population from various regions including resource-limited settings support the need for wider accessibility of HIV self-testing (HIV-ST) to reach those who may not otherwise have access to testing. Therefore, HIV-ST has untapped potential as a strategy to improve access to HIV testing and to increase testing frequency among key high-risk populations and their partners. Though HIV-ST has emerged as a safe, acceptable, and effective way to reach people, there are several roadblocks to implementing the HIV-ST policy, and fast-track policy implementation needs to be necessitated with newer or modified strategic plans

Differently Environment Stable Bio-Silver Nanoparticles: Study on Their Optical Enhancing and Antibacterial Properties

<div><p>Generally, limited research is extended in studying stability and applicational properties of silver nanoparticles (Ag NPs) synthesized by adopting ‘green chemistry’ protocol. In this work, we report on the synthesis of stable Ag NPs using plant-derived materials such as leaf extract of Neem (<i>Azadirachta indica</i>) and biopolymer pectin from apple peel. In addition, the applicational properties of Ag NPs such as surface-enhanced Raman scattering (SERS) and antibacterial efficiencies were also investigated. As-synthesized nanoparticles (NPs) were characterized using various instrumentation techniques. Both the plant materials (leaf extract and biopolymer) favored the synthesis of well-defined NPs capped with biomaterials. The NPs were spherical in shape with an average particle size between 14-27 nm. These bio-NPs exhibited colloidal stability in most of the suspended solutions such as water, electrolyte solutions (NaCl; NaNO₃), biological solution (bovine serum albumin), and in different pH solutions (pH 7; 9) for a reasonable time period of 120 hrs. Both the bio-NPs were observed to be SERS active through displaying intrinsic SERS signals of the Raman probe molecule (Nile blue A). The NPs were effective against the <i>Escherichia coli</i> bacterium when tested in nutrient broth and agar medium. Scanning and high-resolution transmission electron microscopy (SEM and HRTEM) images confirmed cellular membrane damage of nanoparticle treated <i>E. coli</i> cells. These environmental friendly template Ag NPs can be used as an antimicrobial agent and also for SERS based analytical applications.</p> </div

Electron microscopy images of bio-Ag NPs exposed <i>E. coli</i> cells.

<p>SEM images of <i>E. coli</i> cells treated with (a-c) <i>A. indica</i> Ag NPs and (d-f) pectin Ag NPs. HRTEM images <i>E. coli</i> cells treated with (g-i) <i>A. indica</i> Ag NPs and (j-l) pectin Ag NPs.</p

Colloidal stability of pectin Ag NPs in different media.

<p>Time dependent UV-Vis absorbance spectra and zeta (HDD and ζ potential value) measurements of pectin Ag NPs dispersed in different media. Pectin Ag NPs dispersed in (a-b; e-f) NaCl, (c-d; g-h) NaNO₃, (i-j; m-n) BSA, (k; o) pH 7 and (l; p) pH 9.</p

Colloidal stability of <i>A. indica</i> Ag NPs in different media.

<p>Time dependent UV-Vis absorbance spectra and zeta (HDD and ζ potential value) measurements of <i>A. indica</i> Ag NPs dispersed in different media. <i>A. indica</i> Ag NPs dispersed in (a-b; e-f) NaCl, (c-d; g-h) NaNO₃, (i-j; m-n) BSA, (k; o) pH 7 and (l; p) pH 9.</p

Colloidal stability of bio-silver nanoparticles in water.

<p>(a) UV-Vis absorbance spectra, and (b) HDD and ζ potential values of <i>A. indica</i> Ag NPs. (c) UV-Vis absorbance spectra and (d) HDD and ζ potential values pectin Ag NPs.</p

Silver nanoparticles characterization.

<p>(a) UV-Vis absorbance spectrum, (b) TEM image (inset SAED pattern) and (c) size distribution histogram pattern of (i) <i>A. indica</i> Ag NPs and (ii) pectin Ag NPs.</p

Molecular structure of biopolymer pectin and Raman analyte Nile Blue A.

<p>Structure of (a) Nile blue A and (b) pectin.</p