Plant 2016; 4(5): 29-36 http://www.sciencepublishinggroup.com/j/plant doi: 10.11648/j.plant.20160405.11 ISSN: 2331-0669 (Print); ISSN: 2331-0677 (Online) Response of Triticum aestivum (L.) Plants Grown Under Cadmium Stress to Polyamines Pretreatments Mostafa Mohamed Rady 1, * , Mohamed Ahmed Seif El-Yazal 1 , Hanan Anwar Aly Taie 2 , Safia Mahmoud Abdel-Mageed Ahmed 1 1 Botany Department, Faculty of Agriculture, Fayoum University, Fayoum, Egypt 2 Plant Biochemistry Department, National Research Centre, Cairo, Egypt Email address: mmr02@fayoum.edu.eg (M. M. Rady), mrady2050@gmail.com (M. M. Rady) * Corresponding author To cite this article: Mostafa Mohamed Rady, Mohamed Ahmed Seif El-Yazal, Hanan Anwar Aly Taie, Safia Mahmoud Abdel-Mageed Ahmed. Response of Triticum aestivum (L.) Plants Grown Under Cadmium Stress to Polyamines Pretreatments. Plant. Vol. 4, No. 5, 2016, pp. 29-36. doi: 10.11648/j.plant.20160405.11 Received: September 13, 2016; Accepted: September 22, 2016; Published: October 11, 2016 Abstract: The role of exogenously-applied polyamines [i.e., spermine (Spm), spermidine (Spd) and putrescine (Put)] in the improvement of cadmium (Cd 2+ ) tolerance in wheat plants, and their effects on growth, yield and its components and changes in the osmoprotectant and endogenous Cd 2+ concentrations and the contents of some nutrients in plants grown under 2.0 mM Cd 2+ stress were assessed. The efficiency of wheat plants to tolerate Cd 2+ stress in terms of growth and yield characteristics was noticed to varying degrees with the three applied polyamines. The reasonable growth of Cd 2+ -stressed seedlings and consequently acceptable grain yield was correlated with the improvements in the concentrations of osmoprotectants and tissue health in terms of relative water content (RWC) and membrane stability index (MSI), and reductions in electrolyte leakage (EL) and tissue Cd 2+ concentration. Results show that, seed soaking in 0.25 mM Spm, 0.50 mM Spd or 1.0 mM Put generated significant better growth and yield characteristics, MSI, RWC, leaf photosynthetic pigment and osmoprotectant concentrations, and nutrient contents than seed soaking with water under 2.0 mM Cd 2+ stress. In contrast, the Cd 2+ concentration and EL were significantly reduced. However, the Cd 2+ -free control was the best treatment when compared to the all other stressed treatments. Seed soaking in 1.0 mM Put was the best, generating wheat plants that most tolerant to Cd 2+ stress than those generated from the other two polyamines. Therefore, this study recommend to use the 1.0 mM Put, as seed soaking treatment for wheat to grow well under Cd 2+ stress. Keywords: Wheat, Cadmium, Polyamines, Osmoprotectants, Growth, Yield 1. Introduction Worldwide, wheat (Triticum aestivum L.) is one of the most important cereal crops used principally as human food. It provides 37% of the total calories and 40% of the protein in the Egyptian people diet [1]. Recently, a great attention of several Egyptian investigators has been directed to increase the productivity of wheat to minimize the gap between the production and consumption. This may be achieved through the increase of unit land area productivity and the increment of cultivated area. Increase of wheat yield per unit of area can be achieved by using the high yielding bred varieties and applying the optimum cultural practices [2]. Cadmium (Cd 2+ ) is believed as one of the most important contaminant in the ecosphere. The main sources of Cd 2+ in environment are mining and smelting of Cd 2+ -containing ores, municipal wastes, pesticides, trace emissions, burning of fossil fuels and phosphorus fertilizers [3, 4]. It has been reported previously that toxic metals have the ability to contaminate various ecosystems via different sources including industrial wastewater disposal, agricultural chemicals, mining, geogenic, etc. [5]. Cadmium is not an essential nutrient and it is one of the heavy metals that are known to generate toxicity even at a very low concentration. It accumulates in plants during growth in edible parts,