Plant Process and Function

en Effect of Pb and Cd on the response of some stress genes and the activity of antioxidant enzymes in date palm leaves Effect of Pb and Cd on the response of some stress genes and the activity of antioxidant enzymes in date palm leaves تنش فلزات سنگین Toxic ions stress پژوهشي Research <div style="text-align: left;"><a name="_Hlk221014418">This study used 18-month-old palm offshoots irrigated with water containing different concentrations of heavy metals: Pb at 100 and 200 mg/kg soil, and Cd at 3 and 6 mg/kg soil. After three months of treatment, a sample of palm leaves was taken for molecular and chemical tests. The results showed that treatment with Pb and Cd increased their concentrations compared with the control sample, especially at high concentrations. This treatment caused stress to the plants and affected their biochemical and molecular characteristics. The content of H2O2 increased significantly in the treatment with 200 mg/kg Pb, reaching the highest level of 1.18±2.67 μmol/g. In contrast, the control sample had the lowest H2O2 content (0.90 ± 0.01 μmol/g). Peroxidase activity also increased significantly during treatment, with the highest enzyme activity (40.49 ± 0.26 units/min/g) observed in the Pb 200 mg/kg group. Treatment with Pb at 200 mg/kg also resulted in the highest soluble carbohydrate content (15.25 ± 0.72 mg/g) compared with the control sample (8.63 ± 0.44 mg/g). Photosynthetic pigments, including chlorophylls and carotenoids, were significantly reduced, especially at high treatment concentrations. Treatment with Pb at 200 mg/kg led to decreases in chlorophyll a and b contents (2.17±0.13 and 1.14±0.07 mg/g Fw, respectively) compared with the control (4.14±0.07 and 1.47±0.11 mg/g Fw, respectively). Similarly, Cd treatment at 3 and 6 mg/kg caused decreases in chlorophyll a and b contents compared with the control sample. The content of carotenoids also decreased significantly (1.02 ± 0.03 and 1.16 ± 0.08 mg/g FW, respectively) when treated with high concentrations of Pb and Cd compared with the control sample (1.87 ± 0.14 mg/g FW). Regarding the effect of heavy metal application on gene expression levels of threonine specific kinase/serine (salt tolerance kinases) (STK), phosphatidylinositol 4,5-bisphosphate 2 (PIP2), pathogenesis-related protein 1 (PR1), and superoxide dismutase (SOD) genes, treatments with Pb at 100 and 200 mg/kg resulted in the highest expression of the PIP2 gene (3.39±0.46 and 4.81±0.30-fold, respectively) compared with the control sample.</a></div> <a name="_Hlk221014418">This study used 18-month-old palm offshoots irrigated with water containing different concentrations of heavy metals: Pb at 100 and 200 mg/kg soil, and Cd at 3 and 6 mg/kg soil. After three months of treatment, a sample of palm leaves was taken for molecular and chemical tests. The results showed that treatment with Pb and Cd increased their concentrations compared with the control sample, especially at high concentrations. This treatment caused stress to the plants and affected their biochemical and molecular characteristics. The content of H2O2 increased significantly in the treatment with 200 mg/kg Pb, reaching the highest level of 1.18±2.67 μmol/g. In contrast, the control sample had the lowest H2O2 content (0.90 ± 0.01 μmol/g). Peroxidase activity also increased significantly during treatment, with the highest enzyme activity (40.49 ± 0.26 units/min/g) observed in the Pb 200 mg/kg group. Treatment with Pb at 200 mg/kg also resulted in the highest soluble carbohydrate content (15.25 ± 0.72 mg/g) compared with the control sample (8.63 ± 0.44 mg/g). Photosynthetic pigments, including chlorophylls and carotenoids, were significantly reduced, especially at high treatment concentrations. Treatment with Pb at 200 mg/kg led to decreases in chlorophyll a and b contents (2.17±0.13 and 1.14±0.07 mg/g Fw, respectively) compared with the control (4.14±0.07 and 1.47±0.11 mg/g Fw, respectively). Similarly, Cd treatment at 3 and 6 mg/kg caused decreases in chlorophyll a and b contents compared with the control sample. The content of carotenoids also decreased significantly (1.02 ± 0.03 and 1.16 ± 0.08 mg/g FW, respectively) when treated with high concentrations of Pb and Cd compared with the control sample (1.87 ± 0.14 mg/g FW). Regarding the effect of heavy metal application on gene expression levels of threonine specific kinase/serine (salt tolerance kinases) (STK), phosphatidylinositol 4,5-bisphosphate 2 (PIP2), pathogenesis-related protein 1 (PR1), and superoxide dismutase (SOD) genes, treatments with Pb at 100 and 200 mg/kg resulted in the highest expression of the PIP2 gene (3.39±0.46 and 4.81±0.30-fold, respectively) compared with the control sample.</a> Antioxidant enzymes, Cadmium, Date palm, Gene expression, Lead Antioxidant enzymes, Cadmium, Date palm, Gene expression, Lead 1 10 http://jispp.iut.ac.ir/browse.php?a_code=A-10-90-7&slc_lang=en&sid=1 Muna Mohammed Najeeb Muna Mohammed Najeeb mounamohammed89@gmail.com No Department of Biology, Faculty of Science, Urmia University, Urmia, Iran Department of Biology, Faculty of Science, Urmia University, Urmia, Iran Rashid Jamei Rashid Jamei r.jamei@urmia.ac.ir Yes Department of Biology, Faculty of Science, Urmia University, Urmia, Iran Department of Biology, Faculty of Science, Urmia University, Urmia, Iran Jalil Khara Jalil Khara j.khara@urmia.ac.ir No Department of Biology, Faculty of Science, Urmia University, Urmia, Iran Department of Biology, Faculty of Science, Urmia University, Urmia, Iran Aqeel Hadi Abdul Wahid Aqeel Hadi Abdul Wahid aqeelhadi6@gmail.com No Department of Horticulture, College of Agriculture, University of Basrah, Iraq Department of Horticulture, College of Agriculture, University of Basrah, Iraq