The present investigation aimed to assess the impact of copper (Cu) stress on the physiological and proteomic behavior of Eucalyptus camaldulensis. E. camaldulensis is likely a potential phytoremediator in areas vulnerable to Cu contamination, such as the industrial areas of Riyadh. To realize this objective, young seedlings of E. camaldulensis were potted in an open area with soil comprised of clay and sand. Different doses of Cu (30, 50, and 100 µM) were applied to the plants as CuSO₄.5H₂O for 6 weeks. Plant growth was monitored during the Cu exposure period, and morphological and physiological indicators were measured once a week to determine the growth rates. A proteomics study was also conducted to find out the influence of Cu stress on proteins. Our results showed that growth was negatively affected by Cu treatment, particularly at the highest concentrations. Moreover, using a proteomic analysis showed 26 targets involved in protein expression, which were separated by matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF/TOF MS). Elevated levels of Cu increased the expression of 11 proteins and decreased the expression of 15 proteins. Changes were detected in proteins involved in photosynthesis, translation, transcription, metabolism, and antioxidant enzymes. Our findings provided insights into the molecular mechanisms related to Cu stress, in addition to its influence on the morphological and physiological attributes of E. camaldulensis seedlings. This investigation aimed to characterize the mechanism behind the impact of Cu stress on the plant.
Keywords: Eucalyptus camaldulensis; copper; growth; pollution; proteomics.