Feverfew (Tanacetum parthenium) is a well-known multi-functional plant with anti-inflammatory, cardiotonic, antiangiogenic, and anticancer effects. The therapeutic value of this plant is due to its phytochemical constitutes, especially parthenolide. Tissue culture techniques have been applied to improve the bioactive components of many herbal plants. Hence, this study, was carried out to establish a protocol for micropropagation of the feverfew plant and to quantify parthenolide content in its micropropagated and conventionally grown plants. To establish an aseptic culture, different concentrations of sodium hypochlorite (NaOCl) were investigated for seed surface sterilization. Besides, the effects of plant growth regulators (PGRs) on the callus induction, shoot organogenesis from callus and in vitro rooting were evaluated. Additionally, the parthenolide yield of the micropropagated and conventionally grown plants was determined by using high-performance liquid chromatography (HPLC). The results showed that surface sterilization of feverfew seeds with 6% NaOCl for 15 min obtained 65.00 ± 2.69% aseptic seeds. Murashige and Skoog (MS) medium supplemented with 0.4 mg/L thidiazuron (TDZ) and 2 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D) resulted in 86.00 ± 1.72% callus induction. The highest number of shoots (5.00 ± 0.15) per explant was obtained in the treatment of MS medium supplemented with 5 mg/L zeatin. MS medium fortified with 3 mg/L indole-3-butyric acid (IBA) produced the maximum number of roots per plantlet (8.90 ± 0.35). A total of 90% of the micropropagated plantlets survived when planted in perlite + peat moss (1:1 v/v); the micropropagated plantlets were successfully established in the ex vitro conditions. According to parthenolide analysis, its level was significantly higher in the micropropagated plants than conventionally grown plants. Among different solvents, ethanolic extraction obtained the highest parthenolide content of the feverfew plant. Hence, it can be concluded that micropropagation of feverfew could be applied to produce disease-free planting materials and to improve the parthenolide content of the feverfew plant.

Over the last few decades, biotechnology research has advanced to the point where it is now possible to improve essential agricultural crops. Synthetic seed manufacturing has opened up new possibilities of in vitro plant propagation technique since it has various practical benefits on a commercial scale for the cultivation of a wide range of agricultural crops. It is one of the most important tools for plant tissue culture breeders and scientists, since it provides significant benefits for massive production of distinct (elite) plant species. Synthetic seeds offer a promising strategy for mass plant production in a way of encapsulation of non-embryonic or embryonic (somatic embryos) tissues in a gel-like matrix, such as shoot buds, shoot tips, microshoots, protocoms and nodal segments. When the strategies minimize the cost of the production of elite plant genotypes, this strategy can be adapted for commercial production. The technology of the synthetic seed necessitates the use of in vitro growth systems in order to produce viable materials that can be converted into plants on a wide scale. The discovery of an artificial seed technology opens up new possibilities of a promising strategy for improving a wide range of commercially significant plant species, including cereals, fruit crops, medicinal plants, and vegetable crops, which we focus on in this review article.

In order to investigate the possibility for in in vitro fast regeneration of Dianthus caryophyllus, different concentrations of Kinetin (Kin), 2,4-Dichlorophenoxy Acetic Acid (2,4-D) had been tested for induction of callus by leaves and stems explant using Murashige and Skoog (MS) medium. After two months in culture, response callus in the induction rate, fresh and dry weight, texture and color were evaluated.  MS medium that contained 4.5 mg.L-1 2, 4-D was suitable for callus induction with leaf explants. The combination of 0.4 mg.L-1 Kin and 2.0 mg.L-1 2, 4-D also demonstrated a wonderful induction of callus on stem explants. In addition to the culture medium complemented by Kin and 2, 4-D, the influence of Zeatin at various concentrations (0.0, 0.4, 0.8 or 1.0 mg.L-1) was assessed.  In MS medium that  contained  0.4 mg.L-1 Kin+ 2.0 mg.L-1 2,4-D+ 1.0 mg.L-1 Zeatin, rapid callus induction and also more callus proliferation from stem explants were detected. Results indicate on callus induction that, Zeatin was more successful than Kin or 2, 4-D, but other combinations directly developed a shoot. Callus obtained from stems explant was friable, white and yellow, while callus from leaf explants was green.

Gazania rigens(L.) Gaertn. (Asteraceae) is a medicinal plant with high ornamental potential and use in landscaping. The therapeutic potential of sesquiterpene lactones (SLs) as plant natural products for pharmaceutical development has gained extensive interest with costunolide (chemical name: 6E,10E,11aR-6,10-dimethyl-3-methylidene-3a,4,5,8,9,11a-hexahydrocyclodeca[b]furan-2-one) used as a popular herbal remedy due to its anti-cancer, antioxidant, anti-inflammatory, anti-microbial, anti-allergic, and anti-diabetic activities, among others. In the present study, two explant types (leaf, stem) and four 2,4-dichlorophenoxy acetic acid (2,4-D) concentrations (0, 0.5, 1 and 2 mg/L) were tested for callusing potential. The results showed that stem explants treated with 1.5 mg/L 2,4-D exhibited higher callus induction percentage (90%) followed by leaf explants (80%) with 1 mg/L 2,4-D, after a 4-week period. Cell suspension cultures were established from friable callus obtained from stem explants following a sigmoid pattern of growth curve with a maximum fresh weight at 20 days of subculture and a minimum one at 5 days of subculture. In the following stage, the effects of elicitation of cell suspension cultures with either yeast extract (YE) or methyl jasmonate (MeJA), each applied in five concentrations (0, 100, 150, 200 and 250 mg/L) on cell growth (fresh and dry biomass) and costunolide accumulation were tested. After 20 days of culture, YE or MeJA suppressed cell growth as compared to the non-elicited cells, while costunolide accumulation was better enhanced under the effect of 150 mg/L MeJA followed by 200 mg/L YE, respectively. In the subsequent experiment conducted, the optimal concentration of the two elicitors (200 mg/L YE, 150 mg/L MeJA) was selected to investigate further elicitation time (0, 5, 10, 15 and 20 days). The results revealed that YE biotic elicitation stimulated cell growth and costunolide production, being maximum on day 20 for fresh biomass, on day 5 for dry biomass and on day 15 for the bioactive compound. Accordingly, cell growth parameters were maximized under the effect of abiotic elicitation with MeJA for 15 days, while highest costunolide content was achieved after 10 days. Overall, MeJA served as a better elicitor type than YE for biomass and costunolide production. Irrespective of elicitor type, elicitor concentration and elicitation time, maximal response was obtained with 150 mg/L MeJA for 10 days regarding costunolide accumulation (18.47 ppm) and 15 days for cell growth (fresh weight: 954 mg and dry weight: 76.3 mg). The application of elicitors can lead the large quantity of costunolide to encounter extensive range demand through marketable production without endangering ofG. rigens.Graphical Abstract