Ameliorative role of copper nanoparticle in alleviating salt-induced oxidative stress in fenugreek ( Trigonella foenum-graecum L.) plants

Climate change is considered one of the most important risks threatening humanity because of its negative impact on increasing the salinity of agricultural lands, which in turn leads to a decrease in crop yields. Therefore, finding a safe and effective tool to increase the resistance of agricultural crops to salt stress was the key objective of this research. The effects of synthesized copper nanoparticles (Cu NPs) (biologically or chemically) treatments on the growth, physiochemical aspects of salinity stressed Fenugreek plants are investigated in this study. The CuO nanoparticles (NPs), produced by green and chemical synthesis methods, were analyzed using techniques such as X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), and UV-Visible (UV-Vis) spectroscopy. The preliminary characterization was done by the spectral study, which confirms the absorbance band at 430 and 465 nm by green and chemical synthesis, respectively. The results of the TEM and DLS studies showed that the copper oxide nanoparticles, produced via green and chemical techniques, are spherical in shape, possessing average diameters of 53.7 nm and 36.2 nm, respectively. The XRD graph showed the crystalline and monoclinic phases of CuO nanoparticles. Following a 33-day period of plant life, markers of the plant's recovery from stress destruction included morphological traits, plant pigments, osmolytes levels, anthocyanin, shikimic acid, phenols, and antioxidant enzyme activity. In stressed plants, measurements of soluble protein content, photosynthesis, soluble sugars, and vegetative growth all showed severe declines. In contrast, as compared to plants that were not under stress, the levels of proline, phenol, malondialdehyde, hydrogen peroxide, and antioxidant enzyme activity rose. When applied to both unstressed and stressed plants, the positive effects of synthesized copper nanoparticles (Cu NPs) have been shown to boost all growth metrics, photosynthetic pigments, proline, phenol, anthocyanin, shikimic acid, and enzyme activities relative to control. Reductions in MDA and H2O2 levels indicate that salinity's detrimental effects on fenugreek plants were notably lessened. Ultimately, this study showed that fenugreek plants could benefit from the use of copper nanoparticles as an approach to reducing salt stress, which would increase crop development and yield.