Explore the vast range of titles available.

Over the past decade, silver nanoparticles have garnered attention due to their unique properties and extensive applications in various sectors of science and technology. Herein, we report a facile, cost-effective, and eco-friendly synthesis of stable silver nanoparticles (Ag NPs) employing L-Aspartic acid as a reducing agent. Using hydrothermal treatment, we precisely control their shape, size, and porosity to enhance catalytic performance. The Ag NPs were characterized by various state-of-the-art tools, such as UV–Visible, FL, XRD, FTIR, DLS, Zeta potential, FESEM, TEM, and Raman spectroscopy. The successful synthesis of pure Ag NPs with face-centered cubic (FCC) phase was confirmed through UV–Vis, XRD, and EDX analyses. The as-synthesized Ag NPs possess spherical morphology with an average particle size of 33 nm. The SAED pattern exhibits concentric ring like structure, confirming the polycrystalline nature of the Ag NPs. The high negative zeta potential value (−33.6 mV) of the Ag NPs indicates excellent stability in aqueous suspension. Furthermore, the as-synthesized Ag NPs demonstrated excellent catalytic reduction abilities against MB, MO, and 4-NP pollutants in the presence of sodium borohydride, achieving rate constants of 2.267 × 10−1, 1.331 × 10−1, and 1.828 × 10−1 min−1, respectively. Moreover, the antibacterial activity of Ag NPs was assessed against five pathogenic bacterial strains such as: S. mutans, S. pyogenes, S. typhi, S. flexneri, and V. cholerae by agar well diffusion method. The results demonstrated that L-Aspartic acid capped Ag NPs possess promising catalytic and antibacterial activities, underscoring their significant potential for use as catalysts or antimicrobial agents.

Hypericum perforatum L., commonly known as St. John’s wort is an important medicinal plant, belonging to family Hypericaceae. Among all species of Hypericum, H. perforatum is most investigated and exploited. It is sold as one of the world’s topmost retailing antidepressants. This plant possesses antibacterial, antiviral, anti-inflammatory, and anticancerous properties. These medicinal properties are attributed to the presence of bioactive compounds, such as hypericins and pseudohypericins (naphthodianthrones), hyperforin and adhyperforin (prenylated acylphloroglucinols), quercetin, rutin, isoquercetin, and catechin (flavonoids), chlorogenic acid, caffeic acid, and tannic acid (phenols) and xanthones. The conventional methods of propagation of H. perforatum are time consuming and field grown plants are exposed to biotic and abiotic challenges which affect its phytochemical constituents. Moreover, these methods are also unable to meet the commercial demand of secondary metabolites. Therefore, in order to meet the growing raw material demand of pharmaceutical industries there is a need to develop effecient in vitro plant regeneration protocols for large scale production of H. perforatum plants and other biotechnological methods (cell, tissue and organ culture, cell suspension culture, hairy root culture, elicitation, etc.) for improvement of target bioactive compounds. The present review provides a comprehensive account of the available information on in vitro plant regeneration and biotechnological approaches used to enhance the secondary metabolite(s) content in H. perforatum during the past years. It also deals with the unexplored areas which might be exploited for drug discovery.

Withania somnifera (L.) Dunal is a valuable medicinal plant in the Solanaceae family. It is commonly known as Ashwagandha and is widely distributed around the globe. It has multiple pharmacological properties owing to the existence of diverse secondary metabolites viz., withanolide A, withanolide D, withaferin A, and withanone. It is in great demand in the herbal industry because of its extensive use. In this background, the major challenge lies in the rapid multiplication of elite cultivars of W. somnifera in order to produce genetically and phytoconstituents uniform plant material for pharmaceutical industries. Thus it is necessary to explore various biotechnological approaches for the clonal mass propagation and synthesis of pharmaceutically important constituents in W. somnifera. Though there are several studies on in vitro propagation on W. somnifera, yet many factors that critically influence the in vitro response and withanolides production need to be fine-tuned in the pretext of the existing knowledge. The current review focuses on the advancements and prospects in biotechnological interventions to meet the worldwide demands for W. somnifera and its bioactive compounds. This update on in vitro studies on W. somnifera will be useful to many researchers, entrepreneurs, and herbal industries looking for its in vitro mass multiplication and scientific utilization.Key messageWithania somnifera is a high value medicinal plant. The present review discusses the advancements in in vitro propagation and important secondary metabolites biosynthesis of W. somnifera.

Main conclusionThis review highlights the economic importance of sweet potato and discusses new varieties, agronomic and cultivation practices, pest and disease control efforts, plant tissue culture protocols, and unexplored research areas involving this plant.Abstract Sweet potato is widely consumed in many countries around the world, including India, South Africa and China. Due to its valuable nutritional composition and highly beneficial bioactive compounds, sweet potato is considered a major tuber crop in India. Based on the volume of production, this plant ranks seventh in the world among all food crops. Sweet potato is considered a “Superfood” by the ‘Centre for Science in the Public Interest’ (CSPI), USA. This plant is mostly propagated through vegetative propagation using vine cuttings or tubers. However, this process is costly, labour-intensive, and comparatively slow. Conventional propagation methods are not able to supply sufficient disease-free planting materials to farmers to sustain steady tuber production. Therefore, there is an urgent need to use various biotechnological approaches, such as cell, tissue, and organ culture, for the large-scale production of healthy and disease-free planting material for commercial purposes throughout the year. In the last five decades, a number of tissue culture protocols have been developed for the production of in vitro plants through meristem culture, direct adventitious organogenesis, callus culture and somatic embryogenesis. Moreover, little research has been done on synthetic seed technology for the in vitro conservation and propagation of sweet potato. The current review comprehensively describes the biology, i.e., plant phenotypic description, vegetative growth, agronomy and cultivation, pests and diseases, varieties, and conventional methods of propagation, as well as biotechnological implementation, of this tuber crop. Furthermore, the explored and unexplored areas of research in sweet potato using biotechnological approaches have been reviewed.

Rhodiola imbricata is a rare and endangered plant of the Trans-Himalayan region having important medicinal properties. It holds immense therapeutic value against a wide range of diseases and health problems including hypoxia, cancer, stress, anxiety, fatigue, and gastrointestinal problems. The plant which is normally propagated through seeds suffers from drawbacks such as limited seed availability, low seed viability, and germination, limited geographical distribution, slow growth, and slow accumulation of secondary metabolites. Owing to the growing demand for this plant, a novel, highly efficient liquid culture system using meta-Topolin (mT) was developed for its rapid multiplication and continuous production of important bioactive compounds. A comparative analysis was conducted to evaluate the response of shoot multiplication, rooting, and secondary metabolite content in the solid and liquid culture media. In vitro seedlings were inoculated on Murashige and Skoog’s (MS) (1962) medium supplemented with different concentrations of cytokinins. Among the tested cytokinins, the maximum number of shoots were observed in 20 mL of liquid MS medium supplemented with mT (5.0 µM). While Indole-3-butyric acid (IBA) (10.0 µM) exhibited the highest rooting response (95%). Mass propagation of microshoots was achieved using a specialized box, resulting in an improved survival rate of 85% during the subsequent hardening process. The secondary metabolite content, including rosavin, salidroside, tyrosol, total polyphenolic content (TPC), and antioxidant properties were estimated for shoots grown in both agar-gelled solid and liquid culture media. Overall, liquid MS medium supplemented with mT (5.0 µM) was found to be the optimum medium for secondary metabolites production in comparison to solid medium. Further, the genetic and phytochemical stability of the prolong culture of this plant under in vitro conditions were confirmed. This system facilitates large scale production of in vitro plants as well as secondary metabolites throughout the year, which is crucial for various industrial applications.Key messageRhodiola imbricata is an important, rare and endangered medicinal plant. A novel and efficient protocol for improved shoot proliferation and secondary metabolite production was developed using meta-Topolin and liquid culture.

Blepharispermum subsessile DC. is well known for its ethnomedicinal values. This plant has been used traditionally for the treatment of various diseases. Due to over-exploitation, habitat destruction, and climate change B. subsessile has been included in the list as threatened plants. Hence urgent attention is needed for the protection and conservation of this endangered plant. This plant is found in ‘Gurudangar’, Odisha, India and it is declared as Medicinal Plant Conservation Areas for in situ conservation of this plant species along with few other medicinal plants. In vitro propagation is an extremely effective alternative to overcome the limitations of conventional propagation methods and to escalate the production of B. subsessile. Keeping this in view, the present study was envisaged to develop an efficient protocol for in vitro plant regeneration of B. subsessile from cotyledonary node explant. Multiple shoots were induced from the cotyledonary node on Murashige and Skoog’s (1962) (MS) medium supplemented with different types and concentrations of plant growth regulators. A combined effect of 2.0 mg/L meta-Topolin (mT) and 1.0 mg/L indole-3-acetic acid (IAA) when augmented with MS medium was evaluated as optimum for multiple in vitro shoot regeneration from cotyledonary node. Further, in vitro nodal segments were inoculated on different plant growth regulator supplemented medium for upscaling and mT (2.0 mg/L) was found to be best for such in vitro shoot proliferation. The in vitro shoots were rooted on ½ MS medium supplemented with 0.5 mg/L indole-3-butyric acid (IBA). The in vitro regenerated plants were successfully acclimatized in the small pots containing sterile garden soil and sand (1:1) followed by the transfer to larger pots containing garden soil. The genetic fidelity of in vitro regenerated plants was assessed and ascertained by ISSR markers. The phytochemical analysis and antioxidant activity of the in vitro regenerated plants vis-à-vis mother plant were also evaluated to find out the biochemical fidelity.Key messageA robust micropropagation protocol was developed for a threatened medicinal plant Blepharispermum subsessile DC. using axenic seedling on mT supplemented medium and evaluated their genetic fidelity and phytochemical content.

Blepharispermum subsessile is an important threatened medicinal plant of India. This plant has been enlisted in ‘endangered’ category in different states of India due to over-exploitation and unregulated trading. Thus, urgent attention is needed for its conservation. This study presents an efficient in vitro plant propagation protocol for B. subsessile using axenic shoot tip and confirmation of genetic fidelity of the regenerated plants. Axenic shoot tips were inoculated on MS medium supplemented with different concentrations and combinations of plant growth regulators for shoot multiplication. Highest number of shoots per explant (48.1) were found on MS medium augmented with 3.0 mgl−1meta Topolin (mT) and 1.5 mgl−1 Zeatin (Z). Ninety-five percent in vitro shoots were rooted on ½ MS medium augmented with 0.5 mgl−1 Indole-3-butyric acid (IBA). All rooted plantlets were successfully acclimatized and about 70% plants survived. The genetic fidelity of in vitro propagated plants was assessed by ISSR markers and confirmed their genetic integrity with that of the mother plant. This study could be used for conservation of B. subsessile.

Hedychium coronarium J. Koenig is a rhizomatous herb (Zingiberaceae family) and is well known for its uses in traditional systems of medicine for the treatment of various diseases. The plant has been over-exploited and enlisted as a threatened species in India. Thus, there is an urgent attention required for its conservation. Here, a callus-mediated in vitro plant regeneration protocol was developed using leaf sheath of H. coronarium . The optimal medium for callus induction (85.0%) and subsequent proliferation was found to be MS basal medium augmented with 3.0 mg L −1 N 6 -benzyladenine (BA), 0.5 mg L −1 α-naphthaleneacetic acid (NAA), and 3.0% sucrose, and gelled with 0.5% agar. Optimum callus-mediated shoot organogenesis (78.3%; ca. 11.4 shoots/0.5 g of callus) was obtained on MS medium supplemented with 3.0 mg L −1 BA after 6 wk of culture. All the in vitro regenerated shoots were rooted (8.5 roots/shoot) successfully on plant growth regulator–free MS medium. About 90% plantlets were acclimatized on the planting tray filled with garden soil and sand (1:1). Transfer of these plants to larger pots containing garden soil and subsequent field transfer under full sun resulted in cent-percent survival. Monomorphic banding profile obtained using Random Amplified Polymorphic DNA (RAPD) and Inter Simple Sequence Repeat (ISSR) markers ascertained the clonal fidelity of the in vitro regenerated plants. Similarly, the biochemical fidelity of the in vitro regenerated plants vis-à-vis mother plant was ascertained by comparing the composition of essential oil through gas chromatography/mass spectrometry (GC/MS) analysis. Furthermore, the antioxidant activities estimated by DPPH and ABTS free radical scavenging assay and anticancer activities evaluated against two cell lines, i.e. , MCF 7 and MDA-MB 231, also confirmed comparable effectiveness of in vitro regenerated plants to that of the mother plant. Thus, the study has the potential to provide a platform to achieve sustainability by using the in vitro regenerated H. coronarium in place of naturally available population.

A plant regeneration protocol via adventitious shoot organogenesis from internode explants of Paederia foetida (Skunk vine) is reported here for the first time. Three explants (leaf, mature internode and internode derived from axenic shoot cultures) were tested for shoot organogenesis. Leaf explants failed to induce adventitious shoots whereas axenic internode explant was found to be superior to mature internode explants for the induction of adventitious shoots. Axenic internode explants cultured on MS medium supplemented with 3.0 mg/l BAP showed maximum (86.7 %; 10.4 shoots per explant) adventitious shoot organogenesis. The regenerated shoots were best rooted (90 %; 14 roots per shoot) on half-strength MS medium. Eighty percent of the rooted shoots were successfully acclimatized in soil: sand (1:1) mixture. All these acclimatized plants were successfully transferred to larger pots containing garden soil and subsequently established in the field.