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In this past decade, the bond between agriculture, food security, and climate change has become increasingly strong. Agriculture is recognized as one of the most endangered systems adversely affected by human activities and environmental issues. In particular, abiotic stress limits the quantity and quality of plant-based food. Heat stress, drought, and salinity impact plants at all different life stages, inducing morphological and physiological changes and provoking a reduction in their nutritional value. Accordingly, low-quality food results in a serious risk for the health of people worldwide. In this scenario, different genetic and biotechnological strategies have been investigated, including the use of New Plant Breeding Techniques (NBTs) and plant cell cultures. In this review, we describe how abiotic stresses alter the property and availability of nutritious food. In addition, we illustrate the advanced techniques that could be employed to address these issues and ameliorate the agricultural practices

Melanoma is a malignant neoplasm of melanocytes in the skin, and its occurrence is increasing annually. Plant-based products contain active compounds with low toxicity and are accessible alternatives for melanoma cancer treatment. The biotechnology approach for obtaining plant-based products provides continuity and allows the high-yield production of phytochemically uniform biomass. The callus biomass of Eryngium planum L. and Lychnis flos-cuculi L. was induced on Murashige and Skoog (MS) medium supplemented with growth regulators. A combination of 3.0 mg/L of 3,6-dichloro-2-methoxybenzoic acid (dicamba) and 0.3 mg/L of 1-phenyl-3-(1,2,3-thiadiazol-5-yl)urea—(thidiazuron) was used to obtain E. planum callus. Meanwhile, the callus of L. flos-cuculi was cultivated on MS medium with 2.0 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D). Methanolic extracts (EpME and LFcME), including 40% MeOH fractions (Ep40MF and LFc40MF) and 80% MeOH fractions (Ep80MF and LFc80MF), of E. planum and L. flos-cuculi cell biomass were prepared. Their cytotoxicity activity was assessed in human fibroblast cells (MRC-5) and human melanoma cells (MeWo) by direct cell counting and 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Qualitative analyses using thin-layer chromatography and UPLC-HRMS/MS chromatograms showed the presence of phenolic acids and saponins within the extracts and fractions of both cell biomasses. LFc80MF and Ep80MF showed the strongest toxicity against the MeWo cell line, with IC50 values of 47 ± 0.5 and 52 ± 4 μg/mL after 72 h of treatment. EpME and LFcME had IC50 values of 103 ± 4 and 147 ± 4 µg/mL, respectively. On the other hand, Ep40MF and LFc40MF were less toxic against the MeWo cell line compared to the extracts and 80% MeOH fractions, with IC50 values of 145 ± 10 and 172 ± 7 µg/mL. This study suggests that the obtained extracts and fractions of E. planum and L. flos-cuculi cell biomass potentially possess significant cytotoxic activity against MeWo cells, which work in a time and dose-dependent manner. Although the extracts and 80% MeOH fractions were more potent, the 40% MeOH was shown to be more selective against the MeWo than the control MRC-5 cells.

Sedum telephium is a succulent plant used in traditional medicine, particularly in Italy, for its efficacy in treating localized inflammation such as burns, warts, and wounds. Fresh leaves or freshly obtained derivatives are directly applied to the injuries for these purposes. However, challenges such as the lack of microbiologically controlled materials and product standardization prompted the exploration of more controlled biotechnological alternatives, utilizing in vitro plant cell cultures of S. telephium. In the present study, we used HPLC-DAD analysis to reveal a characteristic flavonol profile in juices from in vivo leaves and in vitro materials mainly characterized by several kaempferol and quercetin derivatives. The leaf juice exhibited the highest content in total flavonol and kaempferol derivatives, whereas juice from callus grown in medium with hormones and callus suspensions showed elevated levels of quercetin derivatives. The in vitro anti-inflammatory and wound-healing assays evidenced the great potential of callus and suspension cultures in dampening inflammation and fostering wound closure, suggesting quercetin may have a pivotal role in biological activities.

Anthocyanins are water-soluble pigments found in plants. They exist in various colors, including red, purple, and blue, and are utilized as natural colorants in the food and cosmetics industries. The pharmaceutical industry uses anthocyanins as therapeutic compounds because they have several medicinal qualities, including anti-obesity, anti-cancer, antidiabetic, neuroprotective, and cardioprotective effects. Anthocyanins are conventionally procured from colored fruits and vegetables and are utilized in the food, pharmaceutical, and cosmetic industries. However, the composition and concentration of anthocyanins from natural sources vary quantitively and qualitatively; therefore, plant cell and organ cultures have been explored for many decades to understand the production of these valuable compounds. A great deal of research has been carried out on plant cell cultures using varied methods, such as the selection of suitable cell lines, medium optimization, optimization culture conditions, precursor feeding, and elicitation for the production of anthocyanin pigments. In addition, metabolic engineering technologies have been applied for the hyperaccumulation of these compounds in varied plants, including tobacco and arabidopsis. In this review, we describe various strategies applied in plant cell and organ cultures for the production of anthocyanins.

Natural extracts of Hypericum perforatum L. are widely used in the pharmaceutical industry due to their antiviral, antioxidant, antibacterial, antidiabetic, and antidepressant activities. Plant biotechnological methods are gaining more attention as efficient and biosustainable approaches for the production of high value compounds by using plant callus cultures in vitro. The aim of this research was to evaluate the influence of phytohormones on the formation of Hypericum perforatum L. callus culture, to explore antioxidant and antibacterial activities, and to determine the amounts of phytochemicals in the analyzed extracts. Callus cultures were induced on Murashige and Skoog basal medium supplemented with phytohormones (auxins, cytokinins, and salicylic acid), and containing newly synthesized compound N-(1,3-dioxoisoindolin-2-yl)-3-((4-methoxyphenyl)amino)propanamide. The antioxidant activities of callus cultures were evaluated using DPPH and FRAP assays and the enzyme antioxidants (superoxide dismutase, catalase, and ascorbate peroxidase) were evaluated. The antibacterial activity of plant extracts was screened against Escherichia coli and Bacillus subtilis bacteria by the diffusion agar method. There was a significant positive correlation between total phenolic content and high antioxidant efficiency in Hypericum perforatum L. callus cultures, which were formed on Murashige and Skoog medium supplemented with auxin, cytokinin, and salicylic acid (100 µM). Our results have demonstrated that callus cultures generated on MS medium supplemented with N-(1,3-dioxoisoindolin-2-yl)-3-((4-methoxyphenyl)amino)propanamide and cytokinin BAP (0.5 mg L−1) exhibited improved antioxidant activities for the first time.

Modern plant biotechnology often faces the problem of obtaining a stable and powerful vector for gene overexpression. It is known that introns carry different regulatory elements whose effects on transgene expression have been poorly studied. To study the effect of an intron on transgene expression, the stilbene synthase 11 (VaSTS11) gene of grapevine Vitis amurensis Rupr. was selected and overexpressed in grapevine callus cell cultures and several plant generations of Arabidopsis thaliana as two forms, intronless VaSTS11c and intron-containing VaSTS11d. The STS genes play an important role in the biosynthesis of stilbenes, valuable plant secondary metabolites. VaSTS11d contained two exons and one intron, while VaSTS11c contained only two exons, which corresponded to the mature transcript. It has been shown that the intron-containing VaSTS11d was better expressed in several generations of transgenic A. thaliana than VaSTS11c and also exhibited a lower level of cytosine methylation. As a result, the content of stilbenes in the VaSTS11d-transgenic plants was much higher than in the VaSTS11c-transgenic plants. Similarly, the best efficiency in increasing the content of stilbenes was also observed in grapevine cell cultures overexpressing the intron-containing VaSTS11d transcript. Thus, the results indicate that an intron sequence with regulatory elements can have a strong positive effect on both transgene expression level and its biological functions in plants and plant cell cultures.

Abstract Thevetia peruviana is a medicinal plant that has valuable secondary terpenoid-type metabolites and phenolic compounds. Some flavonoid compounds of pharmaceutical interest stand out in the latter group. The concentration of these bioactive compounds in natural conditions is limited by environmental; therefore, it has been considered necessary to make in vitro plant cell suspension cultures that admit the use of elicitors to increase the content of active principles. Accordingly, in this study, for the optimization of flavonoid production in cell suspension culture of T. peruviana, different parameters related to elicitation with methyl jasmonate (MeJa), and salicylic acid (SA) were evaluated, at stirred flask scale. Firstly, 3 μM MeJa and 300 μM SA were added separately in cell cultures of T. peruviana, to assess their potential effects. Secondly, several experimental conditions were evaluated, for optimization purpose. In the first part, MeJa and SA increased the total flavonoid content, in 1.07 and 1.3 times, respectively, compared to the control culture; in the second part, total flavonoid content produced in MeJa mediated cell suspension cultures were 4.14 mg QE/g DW (milligrams of quercetin equivalent per gram of dry biomass) with: concentration 0.3 μM, addition time day 5 and harvest time 90 h. On the other hand, total flavonoid content produced in SA mediated cell suspension cultures were 3.75 mg QE/g DW with: concentration 100 μM, addition time day 0 and harvest time 96 h. Elicitation of cell suspension cultures of T. peruviana with MeJa and SA under their ideal parameter values increased flavonoid content.

The demand for metallic nanoparticles synthesized using green methods has increased due to their various therapeutic and clinical applications, and plant biotechnology may be a potential resource facilitating sustainable methods of AgNPs synthesis. In this study, we evaluate the capacity of extracts from Randia aculeata cell suspension culture (CSC) in the synthesis of AgNPs at different pH values, and their activity against pathogenic bacteria and cancer cells was evaluated. Using aqueous CSC extracts, AgNPs were synthesized with 10% (w/v) of fresh biomass and AgNO3 (1 mM) at a ratio of 1:1 for 24 h of incubation and constant agitation. UV-vis analysis showed a high concentration of AgNPs as the pH increased, and TEM analysis showed polydisperse nanoparticles with sizes from 10 to 90 nm. Moreover, CSC extracts produce reducing agents such as phenolic compounds (162.2 ± 27.9 mg gallic acid equivalent/100 g biomass) and flavonoids (122.07 ± 8.2 mg quercetin equivalent/100 g biomass). Notably, AgNPs had strong activity against E. coli, S. pyogenes, P. aeruginosa, S. aureus, and S. typhimurium, mainly with AgNPs at pH 6 (MIC: 1.6 to 3.9 µg/mL). AgNPs at pH 6 and 10 had a high antiproliferative effect on cancer cells (IC50 < 5.7 µg/mL). Therefore, the use of cell suspension cultures may be a sustainable option for the green synthesis of AgNPs.

Stilbenes are plant defense compounds known to rapidly accumulate in grapevine and some other plant species in response to microbial infection and several abiotic stresses. Stilbenes have attracted considerable attention due to valuable biological effects with multi-spectrum therapeutic application. However, there is a lack of information on natural signaling pathways and transcription factors regulating stilbene biosynthesis. It has been previously shown that MYB R2R3 transcription factor genes VaMyb40 and VaMyb60 were up-regulated in cell cultures of wild-growing grapevine Vitis amurensis Rupr. in response to UV irradiation. In this study, the effects of VaMyb40 or VaMyb60 overexpression in cell cultures of V. amurensis on their capability to produce stilbenes were investigated. Overexpression of the VaMyb60 gene led to a considerable increase in the content of stilbenes in three independently transformed transgenic lines in 5.9–13.9 times, while overexpression of the VaMyb40 gene also increased the content of stilbenes, although to a lesser extent (in 3.4–4.0 times) in comparison with stilbene levels in the empty vector-transformed calli. Stilbene content and stilbene production in the VaMyb60-transgenic calli reached 18.8 mg/g of dry weight (DW) and 150.8 mg/L, respectively. Using HPLC analysis, we detected eight individual stilbenes: t-resveratrol diglucoside, t-piceid, t-resveratrol, ε-viniferin, δ-viniferin, cis-resveratrol, cis-piceid, t-piceatannol. T-resveratrol prevailed over other stilbenoid compounds (53.1–89.5% of all stilbenes) in the VaMyb-overexpressing cell cultures. Moreover, the VaMyb40- and VaMyb60-transformed calli were capable of producing anthocyanins up to 0.035 mg/g DW, while the control calli did not produce anthocyanins. These findings show that the VaMyb40 and VaMyb60 genes positively regulate the stilbene biosynthesis as strong positive transcription regulators and can be used in biotechnological applications for stilbene production or high-quality viticulture and winemaking.

Stilbenes are plant phenolics known to rapidly accumulate in grapevine and other plants in response to injury or pathogen attack and to exhibit a great variety of healing beneficial effects. It has previously been shown that several calmodulin-like protein (CML) genes were highly up-regulated in cell cultures of wild-growing grapevine Vitis amurensis Rupr. in response to stilbene-modulating conditions, such as stress hormones, UV-C, and stilbene precursors. Both CML functions and stilbene biosynthesis regulation are still poorly understood. In this study, we investigated the effect of overexpression of five VaCML genes on stilbene and biomass accumulation in the transformed cell cultures of V. amurensis. We obtained 16 transgenic cell lines transformed with the VaCML52, VaCML65, VaCML86, VaCML93, and VaCML95 genes (3–4 independent lines per gene) under the control of the double CaMV 35S promoter. HPLC-MS analysis showed that overexpression of the VaCML65 led to a considerable and consistent increase in the content of stilbenes of 3.8–23.7 times in all transformed lines in comparison with the control calli, while biomass accumulation was not affected. Transformation of the V. amurensis cells with other analyzed VaCML genes did not lead to a consistent and considerable effect on stilbene biosynthesis in the cell lines. The results indicate that the VaCML65 gene is implicated in the signaling pathway regulating stilbene biosynthesis as a strong positive regulator and can be useful in viticulture and winemaking for obtaining grape cultivars with a high content of stilbenes and stress resistance.

All parts of Neem (Azadirachta indica A. Juss) show a broad spectrum efficacy against insect pests including insecticidal, anti-feedant or insect repellent activities. Several studies have shown that plant cell cultures can produce azadirachtins. We induced more than 40 novel Neem cell lines in modified Murashige and Skoog (MS) media containing different concentrations of auxins and cytokinins. To enhance the Azadirachtin production from 1 mg/l, it was necessary to optimize the media composition separately for biomass and secondary metabolite production. In light of this complex challenge we used our novel fully automated high-throughput microbioreactor system that allows us a fast and controlled batch and fedbatch screening in 48-well microtiter plates. There is increasing evidence that plants like Azadirachta indica contain endophytes which are able to colonize internal plant tissue without causing visible disease symptoms. The estimated high species diversity of endophytes suggests a rich and almost untapped source of new secondary metabolites. We isolated more than 340 endophytes from various plant tissues and tested if they were able to produce Azadirachtin-A. Here, we present data on isolation of endophytes and induction of callus as well as first results of our microbioreactor system.

The last decades witnessed a great demand of natural remedies. As a result, medicinal plants have been increasingly cultivated on a commercial scale, but the yield, the productive quality and the safety have not always been satisfactory. Plant cell cultures provide useful alternatives for the production of active ingredients for biomedical and cosmetic uses, since they represent standardized, contaminant-free and biosustainable systems, which allow the production of desired compounds on an industrial scale. Moreover, thanks to their totipotency, plant cells grown as liquid suspension cultures can be used as “biofactories” for the production of commercially interesting secondary metabolites, which are in many cases synthesized in low amounts in plant tissues and differentially distributed in the plant organs, such as roots, leaves, flowers or fruits. Although it is very widespread in the pharmaceutical industry, plant cell culture technology is not yet very common in the cosmetic field. The aim of the present review is to focus on the successful research accomplishments in the development of plant cell cultures for the production of active ingredients for cosmetic applications.

Cannabis sativa L. is one of the most-studied species for its phytochemistry due to the abundance of secondary metabolites, including cannabinoids, terpenes and phenolic compounds. In the last decade, fiber-type hemp varieties have received interest for the production of many specialized secondary metabolites derived from the phenylpropanoid pathway. The interest in these molecules is due to their antioxidant activity. Since secondary metabolite synthesis occurs at a very low level in plants, the aim of this study was to develop a strategy to increase the production of such compounds and to elucidate the biochemical pathways involved. Therefore, cell suspensions of industrial hemp (C. sativa L. var. Futura) were produced, and an advantageous elicitation strategy (methyl jasmonate, MeJA) in combination with precursor feeding (tyrosine, Tyr) was developed. The activity and expression of phenylalanine ammonia-lyase (PAL) and tyrosine aminotransferase (TAT) increased upon treatment. Through 1H-NMR analyses, some aromatic compounds were identified, including, for the first time, 4-hydroxyphenylpyruvate (4-HPP) in addition to tyrosol. The 4-day MeJA+Tyr elicited samples showed a 51% increase in the in vitro assay (2,2-diphenyl-1-picrylhydrazyl, DPPH) radical scavenging activity relative to the control and a 80% increase in the cellular antioxidant activity estimated on an ex vivo model of human erythrocytes. Our results outline the active metabolic pathways and the antioxidant properties of hemp cell extracts under the effect of specific elicitors.

Plant cell suspension cultures have several advantages that make them suitable for the production of recombinant proteins. They can be cultivated under aseptic conditions using classical fermentation technology, they are easy to scale-up for manufacturing, and the regulatory requirements are similar to those established for well-characterized production systems based on microbial and mammalian cells. It is therefore no surprise that taliglucerase alfa (Elelyso®) – the first licensed recombinant pharmaceutical protein derived from plants – is produced in plant cell suspension cultures. But despite this breakthrough, plant cells are still largely neglected compared to transgenic plants and the more recent plant-based transient expression systems. Here, we revisit plant cell suspension cultures and highlight recent developments in the field that show how the rise of plants cells parallels that of Chinese hamster ovary cells, currently the most widespread and successful manufacturing platform for biologics. These developments include medium optimization, process engineering, statistical experimental designs, scale-up/scale-down models and process analytical technologies. Significant yield increases for diverse target proteins will encourage a gold rush to adopt plant cells as a platform technology, and the first indications of this breakthrough are already on the horizon.

High temperatures are a significant stress factor for plants. In fact, many biochemical reactions involved in growth and development are sensitive to temperature. In particular, heat stress (HS) represents a severe issue for plant productivity and strategies to obtain high yields under this condition are important goals in agriculture. While selenium (Se) is a nutrient for humans and animals, its role as a plant micronutrient is still questioned. Se can prevent several abiotic stresses (drought, heat, UV, salinity, heavy metals), but the action mechanisms are poorly understood. Se seems to regulate reactive oxygen species (ROS) and to inhibit heavy metals transport. In addition, it has been demonstrated that Se is essential for a correct integrity of cell membranes and chloroplasts, especially the photosynthetic apparatus. Previous results showed that in tobacco (Nicotiana tabacum cv. Bright-Yellow 2) cultures HS (5 min at 50 °C) induced cell death with apoptotic features, accompanied by oxidative stress and changes in the levels of stress-related proteins. In this work we investigated the effect of Se on the responses induced by HS. The obtained results show that Se markedly reduces the effects of HS on cell vitality, cytoplasmic shrinkage, superoxide anion production, membrane lipids peroxidation, activity of caspase-3-like proteases, and the levels of some stress-related proteins (Hsp90, BiP, 14-3-3s, cytochrome c).

Over the past few years, the increasing demand for natural products in the food industry has encouraged remarkable efforts towards the development of biotechnological processes for the production of flavour compounds. The present paper reviews the recent major achievements reported in this field, with a special emphasis on the potential lying in plant cell, microbial cultures and enzyme technology for the production of a wide range of flavours. The use of solid-state fermentation as a means to improve economical feasibility of these processes is also considered.

Cell cultures of Mandevilla velutina have proved to be an interesting production system for biomass and secondary metabolites able to inhibit the hypotensive activity of bradykinin, a nonapeptide generated in plasma during tissue trauma. The crude ethyl acetate extract of cultured cells contains about 31- to 79-fold more potent anti-bradykinin compounds (e.g., velutinol A) than that obtained with equivalent extracts of tubers. Somaclonal variation may be an explanation for the wide range of inhibitor activity found in the cell cultures. The heterogeneity concerning morphology, differentiation, carbon dissimilation, and velutinol A production in M. velutina cell cultures is reported. Cell cultures showed an asynchronous growth and cells in distinct developmental stages. Meristematic cells were found as the major type, with several morphological variations. Cell aggregates consisting only of meristematic cells, differentiated cells containing specialized cell structures such as functional chloroplasts (cytodifferentiation) and cells with embryogenetic characteristics were observed. The time course for sucrose metabolism indicated cell populations with significant differences in growth and metabolic rates, with the highest biomass-producing cell line showing a cell cycle 60% shorter and a metabolic rate 33.6% higher than the control (F2 cell population). MALDI-TOF mass spectrometric analysis of velutinol A in selected cell lines demonstrated the existence of velutinol A producing and nonproducing somaclones. These results point to a high genetic heterogeneity in general and also in terms of secondary metabolite content.

Plant cell culture is traditionally viewed as a unique artificially created biological system represented a heterogenous population of dedifferentiated cells. This system undergoes a continuous process of autoselection based on the intensity and stability of cell proliferation. Obviously, secondary metabolism must be differ in cell culture compared to the plant per ser, because in cell culture metabolites are synthesized and compartmentalized within a single proliferating heterotrophic cell with sparse or underdeveloped vacuoles and plastids. The specifics of formation and regulation of secondary metabolism biosynthesis in plant cells in vitro based on literature survey and our research results has been discussed. We investigated secondary metabolites formation in plant cell cultures of Panax spp., (ginsenosides); Dioscorea deltoidea (steroid glycosides); Ajuga reptans, Serratula coronata, Rhaponticum carthamoides (ecdisteroids); Polyscias spp., (triterpene glycosides), Taxus spp. (taxoids), Stevia rebaudiana (diterpene steviol-glycosides), Stephania glabra (alkaloids). They are some regular trends of secondary metabolites synthesis in the plant cell culture: It can be noted the stable synthesis of the compound promoting cell proliferation. Indeed, cell cultures of Dioscorea deltoidea were demonstrated to accumulate only furostanol glycosides, which promoted cell division. Furostanol glycoside content of Dioscorea strain DM-0.5 was up to 6 - 12% by dry biomass. Panax ginseng and P. japonicus plant cell cultures synthesize as minimum seven triterpene glycosides (ginsenosides), the productivity of these compounds was up to 6.0 - 8.0% on dry biomass. By contrast, the detectable synthesis of diterpene steviol-glycosides in cultivated cells of Stevia rebaudiana initiated in the mixotrophic cultures during chloroplast formation only. Despite these differences, or mainly due to them, plant cell cultures have become an attractive source of phytochemicals in alternative to collecting wild plants. It provides a guideline to bioreactorbased production of isoprenoids using undifferentiated plant cell cultures.

Plant cell culture is traditionally viewed as a unique artificially created biological system represented a heterogenous population of dedifferentiated cells. This system undergoes a continuous process of autoselection based on the intensity and stability of cell proliferation. Obviously, secondary metabolism must be differ in cell culture compared to the plant per ser, because in cell culture metabolites are synthesized and compartmentalized within a single proliferating heterotrophic cell with sparse or underdeveloped vacuoles and plastids. The specifics of formation and regulation of secondary metabolism biosynthesis in plant cells in vitro based on literature survey and our research results has been discussed. We investigated secondary metabolites formation in plant cell cultures of Panax spp., (ginsenosides); Dioscorea deltoidea (steroid glycosides); Ajuga reptans, Serratula coronata, Rhaponticum carthamoides (ecdisteroids); Polyscias spp., (triterpene glycosides), Taxus spp. (taxoids), Stevia rebaudiana (diterpene steviol-glycosides), Stephania glabra (alkaloids). They are some regular trends of secondary metabolites synthesis in the plant cell culture: It can be noted the stable synthesis of the compound promoting cell proliferation. Indeed, cell cultures of Dioscorea deltoidea were demonstrated to accumulate only furostanol glycosides, which promoted cell division. Furostanol glycoside content of Dioscorea strain DM-0.5 was up to 6 - 12% by dry biomass. Panax ginseng and P. japonicus plant cell cultures synthesize as minimum seven triterpene glycosides (ginsenosides), the productivity of these compounds was up to 6.0 - 8.0% on dry biomass. By contrast, the detectable synthesis of diterpene steviol-glycosides in cultivated cells of Stevia rebaudiana initiated in the mixotrophic cultures during chloroplast formation only. Despite these differences, or mainly due to them, plant cell cultures have become an attractive source of phytochemicals in alternative to collecting wild plants. It provides a guideline to bioreactorbased production of isoprenoids using undifferentiated plant cell cultures.