Many methodologies have been established to lessen negative impacts of salinity on plants. Of those methodologies, nanoparticles (NPs) application has achieved great importance thanks to their unique physico-chemical properties. Consequently, formerly respecting encouraging impacts of graphene oxide (GO) and proline (Pro) on different plant processes under non-stress and stress conditions, proline-functionalized graphene oxide nanoparticles “GO–Pro NPs” were synthesized and characterized. Graphite powder, as starting material, was used to synthesize GO using modified Hummers method followed by functionalization of its surface by proline in basic media. Afterward, GO–Pro NPs, GO and Pro, each at 0, 50 and 100 mg L⁻¹ concentrations with three replications, were applied on Moldavian balm (Dracocephalum moldavica L.) plants to assay their effects under non-stress (0 mM) and salt stress (50 and 100 mM) conditions. GO–Pro NPs and Pro effectively alleviated negative effects of salinity through increasing morphological parameters, photosynthetic pigments, chlorophyll fluorescence parameters, chlorophyll index (SPAD), and membrane stability index (MSI) and decreasing hydrogen peroxide and malondialdehyde, as well. Also application of GO–Pro NPs enhanced proline, antioxidant enzymes activities, and most dominant constituents of essential oil. The highest MSI (48.87%) and proline content (15.36 µM g⁻¹ FW) were observed in plant treated with GO–Pro NPs (50 mg L⁻¹) under 100 mM NaCl salinity stress. The GO–Pro NPs treatment at lower dose (50 mg L⁻¹) could be introduced as the best preservative treatment for Moldavian balm under salt stress. GO application mostly had no effect on the measured parameters announcing it as carrier for Pro to enhance its efficiency. In conclusion, GO–Pro NPs application could promote Moldavian balm performance and essential oil under salinity presenting GO–Pro NPs as new treatment against stress conditions.

已经建立了许多方法来减轻盐分对植物的负面影响。在这些方法中，纳米颗粒 (NPs) 应用因其独特的物理化学性质而变得非常重要。因此，以前考虑到氧化石墨烯 (GO) 和脯氨酸 (Pro) 在非胁迫和胁迫条件下对不同植物过程的令人鼓舞的影响，合成并表征了脯氨酸功能化的氧化石墨烯纳米颗粒“GO-Pro NPs”。石墨粉作为起始材料，用于使用改进的 Hummers 方法合成 GO，然后在碱性介质中通过脯氨酸对其表面进行功能化。之后，GO-Pro NPs、GO 和 Pro，分别为 0、50 和 100 mg L ^-1浓度，重复三次，应用于摩尔多瓦香膏（Dracocephalum Moldavica L.) 植物以测定它们在非胁迫 (0 mM) 和盐胁迫 (50 和 100 mM) 条件下的影响。GO-Pro NPs 和 Pro 通过增加形态参数、光合色素、叶绿素荧光参数、叶绿素指数 (SPAD) 和膜稳定性指数 (MSI) 以及降低过氧化氢和丙二醛，有效减轻了盐度的负面影响。GO-Pro NPs 的应用还增强了脯氨酸、抗氧化酶活性和精油的主要成分。在 100 mM NaCl 盐度胁迫下，在用 GO-Pro NPs (50 mg L ^-1 )处理的植物中观察到最高的 MSI (48.87%) 和脯氨酸含量 (15.36 µM g ^-1 FW) 。GO-Pro NPs 以较低剂量（50 mg L ^-1) 可作为盐胁迫下摩尔多瓦香脂的最佳防腐处理。GO 应用程序对测量参数几乎没有影响，宣布它作为 Pro 的载体以提高其效率。总之，GO-Pro NPs 的应用可以提高摩尔多瓦香膏的性能和盐度下的精油，将 GO-Pro NPs 作为抗应激条件的新疗法。