University of Birjand Journal of Horticulture and Postharvest Research 2588-4883 9 Issue 3 2026 09 01 Additive effects of Trichoderma harzianum and TiO2 nanoparticles on growth, cadmium stabilization and macroelements absorption of Mentha piperita L. under cadmium stress 393 414 4090 10.22077/jhpr.2026.9382.1518 EN Tala Nikbin Department of Biology, Faculty of Science, Urmia University, Urmia, Iran Fatemeh Nejadhabibvash Department of Biology, Faculty of Science, Urmia University, Urmia, Iran Journal Article 2025 05 12 <strong>Purpose:</strong> Nowadays, heavy metal pollution of soils has become a serious environmental concern and a potential threat to human health. Peppermint (<em>Mentha piperita </em>L.) is a medicinal and aromatic plant belonging to Lamiaceae family that its essential oil is used in different pharmaceutical industries. This study focused on the effects of arbuscular mycorrhizal fungi (AMF) and different concentrations of titanium dioxide nanoparticles (TiO₂NPs) addition on the growth, absorption of macronutrients<strong>, </strong>migration and bioaccumulation of cadmium in soil- peppermint system. <strong>Research Method:</strong> A factorial experiment was conducted in a completely randomized design with three factors. The first factor was TiO₂NPs (0, 200, and 300 mg/kg), the second factor included Cd-spiked soil (0 and 50 mg/kg soil) and third <em>Trichoderma harzianum</em>.<strong> Findings:</strong> Our results showed cadmium caused negative effects on the growth of peppermint except for shoot and root length. The concentration of all the nutrients assessed (nitrogen and phosphorus) decreased in the presence of cadmium. Mycorrhization under cadmium stress conditions significantly increased nitrogen concentration in roots and shoots by 15% and 3%, respectively, respect to Cd treatment group. Following mycorrhizal inoculation under cadmium stress conditions, phosphorus concentration significantly increased in roots and shoots by 33% and 12%, respectively, respect to Cd treatment group. Similarly, application of TiO₂ nanoparticles at 200 mg/Kg and 300 mg/Kg concentrations alone and in combination with mycorrhizal soil amendments in stress as well as non-stress conditions effec­tively enhanced nutrient acquisition. With the addition of TiO₂NPs and mycorrhiza to soil, the phytoavailability and uptake of Cd by peppermint roots increased. <strong>Research limitations: </strong>There was no limitation. <strong>Originality/Value:</strong> Our research demonstrates that applying AMF and TiO₂NPs could be a sustainable approach to enhancing growth parameters of peppermint plants under Cd stress by improving nutrient acquisition and immobilizing the heavy metal Cd. The results obtained here can provide scientific data for the use of <em>Mentha piperita</em> L. in the remediation of Cd-contaminated soil. https://jhpr.birjand.ac.ir/article_4090_44933d6f3d5b5a5ed2b1ff249bad0f24.pdf