Effect of explant type (leaf, stem) and 2,4-D concentration on callus induction: influence of elicitor type (biotic, abiotic), elicitor concentration and elicitation time on biomass growth rate and costunolide biosynthesis in gazania (Gazania rigens) cell suspension cultures

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