Critical factors influencing in vitro propagation and modulation of important secondary metabolites in Withania somnifera (L.) dunal

Withania somnifera (L.) Dunal: Enhanced production of withanolides and phenolic acids from hairy root culture after application of elicitors

Withania somnifera (L.) Dunal is an important indigenous medicinal plant with extensive pharmaceutical potential. The root is the main source of major bioactive compounds of this plant species including withanolides, withanine, phenolic acids, etc. Hairy root culture (HRC) is a crucial method for low-cost production of active compounds on a large scale. Four different Agrobacterium rhizogenes strains have been used for the hairy root induction. Maximum transformation efficiency (87.34 ± 2.13%) was achieved with A4 bacterial strain-mediated transformed culture. The genetic transformation was confirmed by using specific primers of seven different genes. Seven HR (Hairy root) lines were selected after screening 29 HR lines based on their fast growth rate and high accumulation of withanolides and phenolic acids content. Two biotic and three abiotic elicitors were applied to the elite root line to trigger more accumulation of withanolides and phenolic acids. While all the elicitors effectively increased withanolides and phenolic acids production, among the five different elicitors, salicylic acid (4.14 mg l-1) induced 11.49 -fold increase in withanolides (89.07 ± 2.75 mg g-1 DW) and 5.34- fold increase in phenolic acids (83.69 ± 3.11 mg g- 1 DW) after 5 days of elicitation compared to the non-elicited culture (7.75 ± 0.63 mg g-1 DW of withanolides and 15.66 ± 0.92 mg g-1 DW of phenolic acids). These results suggest that elicitors can tremendously increase the biosynthesis of active compounds in this system; thus, the HRC of W. somnifera is cost-effective and can be efficiently used for the industrial production of withanolides and phenolic acids.

In Vitro Collection for the Safe Storage of Grapevine Hybrids and Identification of the Presence of Plasmopara viticola Resistance Genes

This paper focuses on the creation of an in vitro collection of grapevine hybrids from the breeding program of the Kazakh Scientific Research Institute of Fruit Growing and Viticulture and investigates the presence of Plasmopara viticola resistance mediated by Rpv3 and Rpv12 loci. We looked at the optimization of in vitro establishment using either shoots taken directly from field-grown plants or from budwood cuttings forced indoors. We further screened for the presence of endophyte contamination in the initiated explants and optimized the multiplication stage. Finally, the presence of the resistance loci against P. viticola was studied. The shoots initiated from the field-sourced explants were the more effective method of providing plant sources for in vitro initiation once all plant accessions met the goal of in vitro establishment. The concentration of phytohormones and the acidity of the culture medium have a great effect on the multiplication rate and the quality of in vitro stock cultures. Out of 17 grapevine accessions, 16 showed the presence of single or combined resistance loci against P. viticola. The grapevine accessions identified as carrying Rpv3 and Rpv12 alleles represent important genetic resources for disease resistance breeding programs. These accessions may further contribute to the creation of new elite cultivars of economic interest.

The advent of plant cells in bioreactors

Ever since agriculture started, plants have been bred to obtain better yields, better fruits, or sustainable products under uncertain biotic and abiotic conditions. However, a new way to obtain products from plant cells emerged with the development of recombinant DNA technologies. This led to the possibility of producing exogenous molecules in plants. Furthermore, plant chemodiversity has been the main source of pharmacological molecules, opening a field of plant biotechnology directed to produce high quality plant metabolites. The need for different products by the pharma, cosmetics agriculture and food industry has pushed again to develop new procedures. These include cell production in bioreactors. While plant tissue and cell culture are an established technology, beginning over a hundred years ago, plant cell cultures have shown little impact in biotechnology projects, compared to bacterial, yeasts or animal cells. In this review we address the different types of bioreactors that are currently used for plant cell production and their usage for quality biomolecule production. We make an overview of Nicotiana tabacum, Nicotiana benthamiana, Oryza sativa, Daucus carota, Vitis vinifera and Physcomitrium patens as well-established models for plant cell culture, and some species used to obtain important metabolites, with an insight into the type of bioreactor and production protocols.

Woodfordia fruticosa (L.) Kurz: in vitro biotechnological interventions and perspectives

Woodfordia fruticosa (L.) Kurz is a woody medicinal shrub (Lythraceae) commonly known as the "fire flame bush." W. fruticosa plant parts either alone or whole plant have a long history of recommended use in the Indian medicine systems of Ayurveda, Unani, and Siddha (AUS). This plant is prominently known for its pharmacological properties, viz., antimicrobial, anti-inflammatory, anti-peptic ulcer, hepatoprotective, immunomodulatory, antitumor, cardioprotective, analgesic, and wound healing activities. Its important phyto-constituents, woodfordin C, woodfordin I, oenothein B, and isoschimacoalin-A, exhibit in vitro or in vivo physiological activities beneficial to human health. As the plant is a rich storehouse of phyto-constituents, it is indiscriminately used in its wild habitats. Moreover, due to very poor seed viability and difficult-to-root qualities, it is placed under IUCN list of endangered plant species. For W. fruticosa, biomass production or to its conservation by in vitro regeneration is the best feasible alternative. Till date, only few important in vitro regeneration methods are reported in W. fruticosa. ISSR molecular markers based clonal fidelity and Agrobacterium-mediated transformation has been demonstrated, indicating that W. fruticosa is amenable to genetic manipulation and genome editing studies. This review presents concise summary of updated reports on W. fruticosa phyto-constituents and their biological activities, while a critical appraisal of biotechnological interventions, shortcomings, and factors influencing such potential areas success was presented. The unexplored gaps addressed here are relevant for W. fruticosa scientific innovations yet to come. In this paper, for the first time, we have presented a simple and reproducible protocol for synthetic seed production in W. fruticosa. KEY POINTS: • Critical and updated records on W. fruticosa phytochemistry and its activities • In vitro propagation and elicitation of secondary metabolites in W. fruticosa • Key bottlenecks, in vitro flowering, value addition, and outlook in W. fruticosa.

Volatile profile and micropropagation conditions of Bauhinia forficata Link

Bauhinia forficata Link. is a native South American plant, which possesses volatile compounds with pharmaceutical and medicinal properties such as antidiabetic and anti-inflammatory effects. However, the conservation and propagation of this plant are complicated by its recalcitrant seeds and delayed flowering transition. Hence, tissue culture is employed for the safe and efficient propagation of B. forficata. However, the optimal conditions for the in vitro cultivation of B. forficata remain unknown. Thus, this study aimed to characterize the volatile profile of adult B. forficata field plants and evaluate the effects of different light intensities (43 and 70 μmol m-2 s-1), gas exchange rates (14 and 25 µL L-1 s-1), and exogenous sucrose concentrations (0, 20, and 30 g L-1) on their in vitro development. The results showed that β-caryophyllene is the major volatile compound produced by B. forficata. Moreover, culturing in a medium containing 30 g L-1 of sucrose and flasks with membranes that allow CO2 exchange at the rate of 25 µL L-1 s-1 produced vigorous and hardened plants with high survival rates independent of irradiance. This study is the first to report the optimal in vitro culture conditions for B. forficata as a reference for future studies on micropropagation and secondary metabolite production using this species.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03634-8.

Micropropagation and elicited production of triterpenoid saponin glycosides and stigmasterol via precursor and elicitor feeding in Bacopa floribunda (R.Br.) Wettst.-A potential nootropic herb

Bacopa floribunda (Family: Plantaginaceae) is used in folklore medicines for the management of cognitive dysfunction. It has nootropic, antiaging, anti-inflammatory, anti-cholinesterase, and antioxidant properties. We developed an efficient and reproducible protocol for in vitro propagation of B. floribunda using the nodal explants. We assessed the effects of Murashige and Skoog (MS) medium fortified with various plant growth regulatory substances (PGRs), a precursor, and elicitors and their optimal combinations on regeneration and production of total saponins, triterpenoid saponin glycosides (bacoside A3, bacopaside X, bacopaside II, and bacosaponin C), and stigmasterol content in in vitro grown biomass of B. floribunda. The growth of the shoots and roots was stimulated by MS + 2.0 mg/l BAP + 2.0 mg/l KIN and MS + 0.5 mg/l IAA + 0.5 mg/l IBA + 1.0 mg/l NAA, respectively. After 10 weeks of acclimatization, plantlets of B. floribunda had a survival rate of 95%. The highest total saponin content (35.95 ± 0.022 mg DE/g DW) was noted in the treatment of MS + 2.0 mg/l BAP + 1.5 μM SQ. Similarly, total triterpenoid saponin glycosides and stigmasterol were found maximum in biomass derived from MS + 2.0 mg/l BAP + 1.5 μM SQ and MS + 2.0 mg/l BAP, respectively. At the same treatments, bacoside A3 (1.01 ± 0.195 mg/g DW), bacopaside II (43.62 ± 0.657 mg/g DW), bacopaside X (1.23 ± 0.570 mg/g DW), bacosaponin C (0.19 ± 0.195 mg/g DW), and stigmasterol (7.69 ± 0.102 mg/g DW) were reported. The present findings will help to highlight B. floribunda as a potent memory-enhancing herb, and in future also, it could be a potential substitute to B. monnieri. The current work is the first to describe the micropropagation and the elicited production of bioactive metabolites from the in vitro grown biomass of B. floribunda. In addition, further research is needed on production of bioactives, their pharmacological effects, and the elicited production using callus, cell suspension, and hairy root cultures.

Biology and biotechnological aspect of sweet potato (Ipomoea batatas L.): a commercially important tuber crop

This 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.