Effects of Plant Growth Regulators on in vitro Growth and Callus Induction of Mint (Mentha arvensis L. – Lamiaceae)

Abstract

Introduction: Mentha arvensis L. – Lamiaceae (M. arvensis) is a medicinal plant belonging to the Lamiaceae family and is widely used in the pharmaceutical, cosmetic, and food industries due to its essential oils and bioactive compounds, particularly flavonoids. In vitro culture techniques have been increasingly applied for the rapid propagation and quality improvement of medicinal plants. However, the effects of different plant growth regulators on shoot multiplication, root induction, and secondary metabolite accumulation in M. arvensis have not been fully clarified. Aim: To establish an optimized protocol for culturing in vitro M. arvensis and inducing callus by optimizing plant growth regulators. And using UV-Vis and GC-MS for analysis Results: In particular, M. arvensis explants were cultured on the MS medium supplemented with different amounts of BA solution for shoot multiplication. After data analysis, a promising concentration of BA was obtained at 0.4 mg/L, which enhanced the quality of M. arvensis’s shoots. Besides, the most effective rooting of M. arvensis sample on the medium supplemented with 0.4 mg/L IBA, leading to increase root length (2.44 ± 0.15 cm) and rise of roots per explant (68.12 ± 4.55). NAA and IAA also enhanced root quality and quantity. Additionally, a combination of full-strength MS solution with 2 mg/L Picloram rapidly developed the size of callus while declining the oxidation of callus. Moreover, both in vitro plantlets and callus extraction indicated the high content of bioactive compounds like flavonoids and essential oils. The total flavonoid content was determined by applying US-Vis spectrophotometry (4.66 mg QE/g DW), and the total oil was measured by GC–MS analysis. Conclusion: the optimized procedure of tissue culture is suitable for micropropagation of M. arvensis and can be used as the data for further studies on biomass production and the improvement of bioactive compounds.