A S LONG as we know, little attention has been given to evaluating roles of ZnO nanoparticles (ZnONPs) in plants grown under salinity stress. In the present study, biochemical and molecular responses of salt-stressed soybean cv. Giza111 under different ZnONPs were assessed. Treatment with a high NaCl concentration (250mM) alone caused a significant reduction (65%) in germination percentage as well as a significant decrease in all measured growth parameters (root length, shoot height, fresh and dry weight of roots and shoots) and photosynthetic performance (Fv/Fm) compared to control plants. In contrast, malondialdehyde (MDA) & proline contents, and activities of antioxidant enzymes (catalase CAT, peroxidase POX and superoxide dismutase SOD) were highly increased. In contrast, presoaking of soybean seeds with different concentrations of ZnONPs (25, 50, 100, 200mg/L) stimulated the growth of stressed plants which was exhibited by improved growth parameters and photosynthetic performance as well as lower levels of proline and MDA in stressed plants particularly at ZnONPs concentration of 50 mg/L compared to controls. Moreover, isozyme analysis of CAT, POX and SOD showed variable pattern of alleles at 50mg/L ZnONPs. Accordingly, these results recommend application of 50mg/L ZnONPs for improving the productivity of soybean cultivated in saline soils.

WO Egyptian soybeans varieties, Giza111 and Crawford were selected for the current study. Their seeds were exposed to three doses of gamma-radiation 150, 200, and 250 Gy in order to study their mutagenic effects in the treated seeds and two following generations at various levels. In the first generation (M1), two doses (150 and 200 Gy) were the most effective in enhancement of some agronomic traits like number of stem branches, number of pods per plant, number of seeds per pod and weight of 100 seeds and crop yield. Analysis of protein profiles using SDS-PAGE showed variation among the treatments in each variety, where a total of 35 protein bands were recorded. Three of which were unique bands, one unique band of size 37 kDa was found in the treated seeds before germination (M0) in Crawford at 250 Gy treatment. The other two unique bands (102 and 162 kDa) were found in M2 generation in Crawford at 150 Gy and Giza111 at 200 Gy, respectively. ISSR analysis using five primers gave a total 45, 38 and 28 ISSR bands in M0, M1 and M2, respectively; 4 of which were unique bands. The primer HB14 amplified 6 DNA bands, 2 were unique bands (895 &1050 bp), both in M1 generation of Giza111 at 150 Gy, while primer 844 and 862 amplified only one unique band both found in M0 Giza111 control. They have a molecular size of 888 and 900 bp, respectively. Although, UBC-827 amplified the highest number of bands (7) no unique bands were found.Keywords: Glycine max L., Gamma-radiation, SDS-PAGE, ISSR, polymorphism.Soybean (Glycine max L.) integrates in one crop both the dominant world supply of edible vegetable oil, and the dominant supply of high-protein feed supplements for livestock. Its seed residues and derivatives have a substantial economic importance in a wide range of industrial, food, pharmaceutical, and agricultural products (Smith and Huyser, 1987). In addition, soybean protein is rich in the valuable amino acid lysine (5%) in which most of the cereals are deficient. Moreover, it contains a good quantity of minerals, salts and vitamins. Soybean's oil has been used in Egypt since year 1976, its oil extraction ratio is about 20.5%. Furthermore, soybean is an essential source of protein in the animal and poultry feed (Çelik et al., 2014).Mutations, both spontaneous and induced have been highly successful in changing the fatty acid composition of several oil seed crops. Three reasons have been given for attempts in changing seed oil quality by means of single gene mutations being exceptionally successful. Various soybean mutant lines were identified using mutation, which possessed many desirable traits like habit, low linolenic, high oleic content and resistance to pod shattering (Rahman et al., 1995). In addition, mutational breeding is thought to be as a source of increasing genetic variability and particular improvement could be conferred without importantly changing its satisfactory phenotype (Mudibu et al., 2011; Ambavane et al., 2015(. In plants, induction of genetic and morphological variabilities, using induced mutati...

Two-thirds of the world's overall production of protein feed ingredients, along with all other main oils and fish meals, are produced from soybeans.Genetic variability and relationships among genotypes can be examined using SDS-PAGE of seed storage proteins. In this study, seven Egyptian soybean varieties were assessed for variation in whole seed proteins using SDS-PAGE, which showed an overall of 11 protein bands with diverse molecular weights.To distinguish these soybean genotypes, precise bands of their seed storage protein profiles can be used as markers. In addition, using of five ISSR primers for genome fingerprinting produced a total of 23 ISSR bands which ranged between 990 bp and 248 bp. Of which ten ISSR bands were polymorphic, 6 bands were monomorphic, and 7 bands were unique. SDS-PAGE profiles and ISSR markers revealed the genetic relatedness among the seven soybean genotypes. Cluster analysis based on ISSR data separated the soybean varieties into several sub-clusters, which indicated that ISSRs are more differentiating than did SDS-PAGE. These results could greatly assist in the identification, breeding and preservation of the soybean germplasm.

<p class="042abstractstekst">Little has been done to evaluate the molecular role of ZnO nanoparticles (ZNPs) in regulating biochemical processes and plant yield in response to salt-induced stress. In this study, the molecular response of salt-stressed soybean (‘Giza111’) was assessed under different concentrations of ZNPs (25, 50, 100, and 200 mg l^-1) by measuring some osmolytes, yield parameters, and Na⁺ and K⁺ content. The impact of salinity on the mRNA expression levels of three key salt-tolerance related genes <em>(GmCHX1,</em> <em>GmPAP3</em><em>, </em>and<em> GmSALT3)</em> using qRT-PCR was also determined. The high level of salinity (250 mM NaCl) led to a significant increase in Na⁺content, total soluble proteins, and total soluble carbohydrates and significantly upregulated gene expression of <em>GmCHX1,</em> <em>GmPAP3, </em>and<em> GmSALT3</em>, while reducing K⁺ content, K⁺/Na⁺ ratio and all yield parameters compared to control plants. Soaking soybean seeds in various ZNP concentrations, on the other hand, increased K⁺ content and K⁺/Na⁺ ratio while decreasing Na⁺ content, total soluble proteins, and total soluble carbohydrates in stressed plants, particularly at 50 mg l^-1 ZNPs. Furthermore, <em>GmCHX1,</em> <em>GmPAP3, </em>and<em> GmSALT3 </em>expressions were all downregulated at 50 mg l^-1 ZNPs, which ultimately improved soybean yield parameters. Accordingly, these results recommend the application of 50 mg l^-1 ZNPs for improving the productivity of soybean cultivated in saline soils.</p>