Plant elicitation and TiO2 nanoparticles application as an effective strategy for improving the growth, biochemical properties, and essential oil of peppermint

Tylophora indica (Burm. f.) Merrill is an endangered medicinal plant that possesses various active agents, such as tylophorinine, kaempferol, quercetin, α-amyrin and beta-sitosterol, with multiple medicinal benefits. α-amyrin, a triterpenoid, is widely known for its antimicrobial, anti-inflammatory, gastroprotective and hepatoprotective properties. In this study, we investigated the metabolite profiling of tissues and the effects of cadmium chloride and chitosan on in vitro accumulation of alkaloids in T. indica. First, the callus was induced from the leaf in 2,4-D-, NAA- and/or BAP-fortified MS medium. Subsequent shoot formation through organogenesis and in vitro roots was later induced. Gas chromatography–mass spectrometry (GC–MS)-based phytochemical profiling of methanolic extracts of in vivo and in vitro regenerated plants was conducted, revealing the presence of the important phytocompounds α-amyrin, lupeol, beta-sitosterol, septicine, tocopherol and several others. Different in vitro grown tissues, like callus, leaf and root, were elicited with cadmium chloride (0.1–0.4 mg L−1) and chitosan (1–50 mg L−1) to evaluate the effect of elicitation on α-amyrin accumulation, measured with high-performance thin layer chromatography (HPTLC). CdCl2 and chitosan showed improved sugar (17.24 and 15.04 mg g−1 FW, respectively), protein (10.76 and 9.99 mg g−1 FW, respectively) and proline (7.46 and 7.12 mg g−1 FW), especially at T3 (0.3 and 25 mg L−1), in the leaf as compared to those of the control and other tissues. The antioxidant enzyme activities were also evaluated under an elicitated stress situation, wherein catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX) displayed the highest activities in the leaf at T4 of both of the two elicitors. The α-amyrin yield was quantified with HPTLC in all tested tissues (leaf, callus and root) and had an Rf = 0.62 at 510 nm wavelength. Among all the concentrations tested, the T3 treatment (0.3 mg L−1 of cadmium chloride and 25 mg L−1 of chitosan) had the best influence on accumulation, irrespective of the tissues, with the maximum being in the leaf (2.72 and 2.64 μg g−1 DW, respectively), followed by the callus and root. Therefore, these results suggest future opportunities of elicitors in scaling up the production of important secondary metabolites to meet the requirements of the pharmaceutical industry.

Section: Discussionsupporting

confidence: 91%

Elicitation Induced α-Amyrin Synthesis in Tylophora indica In Vitro Cultures and Comparative Phytochemical Analyses of In Vivo and Micropropagated Plants

Mamgain,

Mujib,

Bansal

et al. 2023

“…Since enzymes are protein compounds, the higher activity of enzymes by application of Myco-Root + TiO 2 NPs was due to the accessibility of nutrients, especially nitrogen [ 57 ]. Similarly, foliar spraying of TiO 2 NPs increased the antioxidant enzymes’ activities, such as CAT and APX in Moldavian balm and peppermint [ 29 , 61 ]. Furthermore, Begum et al [ 62 ] showed that inoculation with AMF increased the antioxidant enzymes’ activities (SOD, CAT, POD, and APX) in Maize under drought stress conditions.…”

Section: Discussionmentioning

confidence: 99%

Optimizing Antioxidant Activity and Phytochemical Properties of Peppermint (Mentha piperita L.) by Integrative Application of Biofertilizer and Stress-Modulating Nanoparticles under Drought Stress Conditions

Ostadi

Javanmard

Machiani

et al. 2022

Drought stress (DS) negatively affects plant growth, productivity, and quality in semi-arid and arid regions. Nowadays, application of biofertilizers and stress-modulating nanoparticles (NPs) improves plant performance under stressful conditions. The study evaluated the impacts of arbuscular mycorrhizal fungi (Myco-Root) and TiO2 NPs on the nutrient uptake, dry yield, essential oil (EO) productivity, and EO quality of peppermint (Mentha piperita L.) under different irrigation regimes. The treatments included three irrigation regimes containing irrigation after 20% (I20, well-watered), 40% (I40, mild DS), and 60% (I60, severe DS) maximum allowable depletion (MAD) percentage of the soil’s available water as well as four fertilizer sources contain no fertilization (control), Myco-Root biofertilizer, TiO2 NPs, and an integrative application of Myco-Root + TiO2 NPs. The results demonstrated that the highest (195.72 g m−2) and the lowest dry yield (78.76 g m−2) of peppermint was obtained in well-watered conditions with integrative application of Myco-Root + TiO2 NPs and severe drought stress (I60) without fertilization, respectively. The dry yield of peppermint was reduced by 27.7 and 53.4% in mild (I40) and severe drought stress (I60), respectively. The maximum EO content (1.49%) and EO yield (2.30 g m−2) was recorded in mild drought stress (I40) treated with Myco-Root + TiO2 NPs. Based on the GC-MS and GC-FID analysis, 29 constituents were identified in peppermint EO, with the major constituents being menthol (38.99–52%), menthone (12.72–20.13%), 1,8-cineole (6.55–7.84%), and neo-menthol (3.14–4.52%), respectively. The maximum content of menthol, 1,8-cineole, and neo-menthol was obtained under mild drought stress (I40) fertilized with Myco-Root + TiO2 NPs. The results indicate that the integrative application of Myco-Root + TiO2 NPs could be used as an alternative method of using chemical fertilizers in sustainable agricultural systems for improving the EO quantity and quality of peppermint grown under drought stress conditions.

“…Kim et al and Złotek et al [ 38 , 39 ] reported that MeJa/JA remarkably enhanced the accumulation of TPC in basil and butter lettuce ( Lactuca sativa L.). Moreover, peppermint-elicited leaves with MeJa showed higher levels of phenolics [ 40 , 41 ]. These findings align with our results; the application of the phytohormone in both phytotrons and the second open field trial stimulated the secretion of the phenolic compounds.…”

Section: Discussionmentioning

confidence: 99%

Inducing the Production of Secondary Metabolites by Foliar Application of Methyl Jasmonate in Peppermint

Kandoudi

Tavaszi-Sárosi

Németh‐Zámboriné

2023

Mentha x piperita is a major source of secondary metabolites (SMs), and developing tools to enhance these compounds would be beneficial to meet the increasing demand in the industry. Elicitation by plant hormones became a new strategy to reach this goal. Three experiments in a climatic chamber and two experiments in an open field were conducted with peppermint to explore the effect of methyl jasmonate (MeJa) on the essential oil (EO) content, EO composition, and the total phenolic content (TPC). The treatment was applied for all experiments by spraying the aerial parts of the plants with a dosage of 2 mM MeJa twice. The treatment influenced all the parameters studied in the trials. The volatile content increased by 9–35%; however, in one trial it remained unchanged. The treatment also affected the main compounds of the EO. Menthone increased significantly in two trials while pulegone and menthofuran decreased. In the case of menthol, the change may also be influenced by the phenological and developmental stages of the plants. In the majority of cases, the TPC was also elevated considerably due to the treatments. MeJa treatments may have promising effects in influencing the accumulation of biologically active compounds and the quality of the drug; therefore, further systematic studies are needed to optimize the technology in vivo.