Callus induction and comparative GC-MS analysis of calli secondary metabolites derived from leaf, stem and root explants of Tephrosia apollinea (Delile) DC.
摘要
Medicinal plants face over-exploitation from mass pharmaceutical production. Plant tissue culture represents an efficient approach for rapid, large-scale production of phytochemicals. Tephrosia apollinea (Fabaceae) is a potential source of natural antioxidants and antimicrobial compounds, yet no callus induction protocols exist for this plant. This work aimed to establish a callus induction protocol using various hormone combinations and to evaluate the phytochemicals of T. apollinea calli derived from leaf, stem, and root explants. The results obtained showed that the medium containing 2,4-Dichlorophenoxyacetic acid (2 mg/L) and 6-Benzylaminopurine (0.25 mg/L) exhibited the highest callus induction with 100% frequency for explants from leaves, and stems, and 75% from roots. Calli from roots had the highest phenolics content (25.0 mg GAE/g), followed by calli from stems and leaves (23.2 mg GAE/g and 19.8 mg GAE/g, respectively). Similarly, antioxidant activity assessed by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) scavenging activity was the highest in calli from roots (IC50 = 1.050 ± 0.079 mg/ml) followed by calli from stems (IC50 = 1.199 ± 0.056 mg/ml) and leaves (IC50 = 1.597 ± 0.098 mg/ml). The significant correlation between DPPH scavenging activity and total phenolic contents (r = 0.987, P < 0.001) indicates that phenolics could be responsible for the antioxidant activities of the calli. Distinct phytochemical profiles were detected in calli induced from different organs. This is the first research that compares calli from different T. apollinea explants, highlighting that root-induced calli have potential antioxidant activity. Although the activity is greater with calli from roots, activity is also noted with calli from stems and leaves. It paves the way for the applications of T. apollinea calli in plant and pharmaceutical biotechnology.