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

Abstract

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.

Improvement in Essential Oil Quantity and Quality of Thyme (Thymus vulgaris L.) by Integrative Application of Chitosan Nanoparticles and Arbuscular Mycorrhizal Fungi under Water Stress Conditions

“…Therefore, the reduction in root AMF colonization under water stress conditions could be attributed to a reduction in activity, spore germination and development of AMF [ 27 ]. In accordance with the results of the present study, Ostadi et al [ 8 ] reported that the AMF colonization rate of peppermint decreased under moderate and severe water deficit conditions.…”

“…In drought stress conditions, the photosynthesis rate of plants decreased due to closing stomata and less absorption of CO 2 , which led to the accumulation of NADPH+H + in plant cells. Therefore, the biosynthesis of secondary metabolites, such as EO compounds, alkaloids, phenolics, etc., improves plant efficiency through the consumption of NADPH+H + [ 8 ].…”

“…The increasing temperature as a result of greenhouse gas emissions led to an increase in drought stress and water shortage in the agricultural sector. In Iran, water stress plays a special role in reducing the yield of plants because the average annual rainfall in this country is 250 mm which is 70% less than the world average [ 8 ]. Water stress is one of the critical abiotic stresses and limiting factors in the productivity of plants, especially in arid and semi-arid regions.…”

“…It has been reported that the inoculation of AMF improves the EO quantity and quality of different medicinal and aromatic plants, such as holy basil ( Ocimum tenuiflorum L.), sage ( Salvia officinalis L.), peppermint ( Mentha piperita L.), thyme (Thymus vulgaris L.), tarragon ( Artemisia dracunculus ), lavender ( Lavandula angustifolia ), etc. [ 5 , 8 , 14 , 24 , 25 ].…”

Arbuscular Mycorrhizal Fungi and Higher Plants

“…Similarly, greater carotenoid content was observed in mycorrhizal Brassica juncea, Lactuca sativa, and Cupressus arizonica (Srivastava et al 2022;Ouhaddou et al 2022;Aalipour et al 2023). In addition, Funneliformis mosseae colonization improved coumarin, phenolic compounds, and flavonoids in Olea europaea, Poncirus trifoliata, and Mentha piperita (Tekaya et al 2022;Ostadi et al 2023). Similarly, elevated activities of leaf APX, CAT, APX, and GR were reported in Ephedra foliata upon colonization by a mixture of Funneliformis mosseae, Claroideoglomus etunicatum, and Rhizophagus intraradices under different levels of water stress (Al-Arjani et al 2020).…”