TY - JOUR T1 - Investigation of the response of two new tomato varieties to the use of exogenous histidine and malate ligands to reduce oxidative stress due to the simultaneous toxicity of copper and nickel in hydroponics culture media TT - بررسی پاسخ دو رقم جدید گوجه‌فرنگی به کاربرد برون‌زای لیگاندهای هیستیدین و مالات جهت کاهش تنش اکسیداتیو ناشی از سمیت همزمان مس و نیکل در محیط کشت هیدروپونیک JF - jispp JO - jispp VL - 9 IS - 36 UR - http://jispp.iut.ac.ir/article-1-1092-en.html Y1 - 2020 SP - 185 EP - 206 KW - Catalase KW - Copper KW - Malon dialdehyde KW - Nickel KW - Peroxidase N2 - The toxicity of heavy metals such as copper and nickel induces oxidative stress in tomato cultivars, due to the production of free radicals and damage to the plasma membrane due to toxic amounts of copper and nickel. When the negative effects of oxidative stress exceed the ability of the antioxidant resistance system, the plant decreases its growth and yield. In this research, we tried to study the simultaneous effect of two histidine and malate ligands on growth improvement and oxidative stress reduction in two new tomato cultivars including Cal J N3 and Early­urbana under simultaneous stresses of copper and nickel in standard hydroponic conditions. 9 post-optimization treatments containing concentrations of 150 and 300 μM of copper and nickel, 300 and 600 μM of histidine and 1 and 2 mM of malate were in the base of Hoagland solution. The treatments were applied to plants cultivated at 50 ml Falcon tube containing Hoagland solution without culture medium in three replications. After treatment, parameters such as morphological growth, total protein content, changes in the activity of catalase and peroxidase enzymes, H2O2 accumulation, Malon dialdehyde and so on were measured in both cultivars. The results showed that the simultaneous use of 600 μM and 2 mM from histidine and malate ligands had a significant effect on oxidative stress improvement on tomato cultivars under 300 μM of nickel and copper stresses. Thus, by adding ligands in stress conditions, oxidant indices improved in comparison with control, indicating a greater correlation between plasma membrane and reduced absorption and transport of nickel and copper free cations. In addition, Cal j N3 cultivar gave a more significant relative response to growth and oxidation parameters of ligands under stress conditions. Ligands seem to be confronted by the influence of heavy metals on physiological, molecular, enzymatic activity and nutrient substitution, which it is suggested to study the effect of ligands on the molecular level. M3 ER -