Induction of some antioxidant enzymes of two bread wheat varieties (Triticum aestivum l.) and two durum wheat (Triticum durum l.) under zinc and bicarbonate stress.

Abstract

  To study effect of Zn,HCO3 Stress in wheat genotype , experiment were conducted in  stats hydroponics technique, in greenhouse of Soil and water sciences department –Agriculture college/Baghdad university intention study effect of Zn and three levels of bicarbonate stress(0,2000,4000 µM.L^-1) ,from KHCO3 silt . Four varieties were uses two from Bread Wheat (Iba99 and Sham6),and two from durum wheat(Sin AL-Jamal and Jndolh). Experiment setup using Complete Randomized Design (CRD).  Results of this Study showed varieties exposure to Zn stress redound in development and emersion Zn deficiency. Zn deficiency differences between wheat varieties .varieties exposure to Zn,HCO3(2000 and 4000 µM.L^-1)stress exacerbate Zn deficiency phenomenon .Accompany Zn deficiency emersion a significant decreased in shoots and roots fresh weight ,especially under Zn ,HCO3 stress assembly.Iba99 from bread wheat given highest values in shoots and roots fresh weight compared with Sham6 varieties .Simi behavior showed in architectures roots .Also Iba99 given highest values in total chlorophyll concentration compared with other varieties. Zinc concentration a significant decreased when varieties grown under Zn, HCO3 stress, with superior Iba99 in active Zinc concentration (84.15 and 73.20 mg.Kg^-1)at highest HCO3 stress (4000 µM.L^-1)under Zn deficient or efficient respectively. Jndolh from durum wheat was superior in all characterizes compared with Sin AL-Jamal. All varieties given high assemble of organic acid (Malic, Citric and Oxalic) in Roots. This is clear signaler on varieties were effected to  Zn and HCO3 stress. Antioxidant enzymes activity (SOD,POD,CAT) were given clear signaler on effected of wheat varieties under Zn,HCO3 stress .This  is deductive on scavenging to ROS eventual from Zn,HCO3 stress.Iba99 given highest values in SOD and CAT(324.4 and 516.5 u.mg p.^-1),when  growth under Zn deficient and highest HCO3 stress (4000 µM.L^-1) respectively. Also Iba99 given highest values in POD enzyme active (65.37 u A.gm^-1) under Zn deficient and highest HCO3 stress(4000 µM.L^-1).Jndolh was superior in all antioxidant enzyme(SOD,POD and CAT)compared with Sin AL-Jamal .    This study suggested capability to use antioxidant enzymes activity as important criterion to separation efficiencies varieties which tolerance Zn, HCO3 stress ,and give early signaler to varieties separation to stress tolerance.