بررسي تاثير نانوساختارهاي كوانتومي كربن دات بر برخي شاخص‌هاي فيزيولوژيك و بيان ژن‌هاي مسير فوق حساس به تنش شوري (SOS) در گياه گوجه فرنگي رقم CH (Lycopersicon esculentum Mill. cv. CH) تحت تنش شوري

Study of the impact of carbon quantum dot nano structures on some physiological parameters an‎d the expression of salt overly sensitive (SOS) pathway genes in Lycopersicon esculentum Mill. cv. CH under salt stress

زيست شناسي گياهي و جانوري

Salinity stress is considered one of the major limiting factors affecting agricultural productivity worldwide, as it disrupts ionic, water, an‎d oxidative homeostasis in plants, thereby reducing crop growth an‎d yield. Given the urgent need to ensure food security an‎d promote sustainable agriculture, the development of novel, cost-effective, an‎d environmentally friendly strategies to enhance plant salt tolerance has attracted considerable attention. In this context, the present study was conducted to investigate the role of carbon dots as biocompatible an‎d biodegradable nanomaterials in improving the salinity tolerance of tomato plants. In this study, carbon dots were synthesized using a microwave-assisted method, an‎d their morphological, optical, an‎d physicochemical properties were characterized by spectrofluorometry, transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), an‎d X-ray diffraction (XRD). Following optimization of carbon dot an‎d salinity concentrations, these treatments were applied to tomato plants under hydro‎ponic conditions. Subsequently, growth parameters, physiological traits, oxidative, osmotic, an‎d ionic stress indices, chlorophyll a fluorescence related to photosystem II activity, as well as the expression of genes involved in the Salt Overly Sensitive (SOS) signaling pathway, were eva‎luated. The results demonstrated that carbon dots significantly improved growth-related parameters, including fresh weight, dry weight, relative water content, an‎d chlorophyll content. In addition, increased levels of proline, total carbohydrates, potassium-to-sodium ratio, antioxidant enzyme activities, an‎d antioxidant compounds, together with reduced reactive oxygen species (ROS) accumulation, indicated enhanced osmotic an‎d oxidative balance in salt-stressed plants. Improved stomatal conductance an‎d photosystem II performance were also observed in treated plants. Furthermore, the decreased upregulation of SOS1, SOS2, SOS3, NHX2, an‎d NHX4 genes in plants subjected to the combined salinity an‎d carbon dot treatment suggested reduced ionic stress an‎d improved sodium homeostasis within plant cells. Overall, the findings of this study indicate that carbon dots can serve as effective, safe, an‎d economical nanomaterials capable of enhancing salinity tolerance in tomato plants through modulation of physiological an‎d molecular responses, thereby contributing to the advancement of sustainable agriculture.

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