ABSTRACT
Abstract The loss of leaves by plant species found in the Cerrado (Brazilian savanna) is an energetically expensive process due to adverse environmental conditions and predation by herbivory. The mature leaves have adaptations which minimize these events. However, the young individuals lack these structures and produce high leaf concentrations of secondary metabolites as a form of protection. These compounds can be used in bioprospection of natural herbicides. Thus, this study aimed to evaluate the phytotoxicity of hexane, ethyl acetate and aqueous extracts of young leaves from Blepharocalyx salicifolius (Kunth) O. Berg on the elongation of wheat coleoptiles (Triticum aestivum L.) and evaluate the potential phytotoxic of ethyl acetate extract on germination, growth and cell size of metaxylem of sesame (Sesamum indicum L.) seedlings. The hexane and ethyl acetate extracts inhibited the elongation of wheat coleoptiles at all concentrations; however, the most promising results were observed in coleoptile fragments treated with the ethyl acetate extract. This treatment changed the mean germination time and the synchrony of sesame seeds, inhibited the growth of shoots and roots, reduced the dry weight of seedlings, led to abnormalities in the seedlings and reduced the length of the metaxylem cells in the sesame seedlings. These results demonstrated the phytotoxic potential of young leaf extracts of B. salicifolius and the high phytotoxicity of the ethyl acetate extract in the initial development of S. indicum.
Resumo A perda das folhas pelas plantas do Cerrado é um processo energeticamente custoso devido às condições ambientais adversas e intensa predação por herbivoria. As folhas maduras possuem adaptações que minimizam esses eventos. Entretanto, os indivíduos jovens carecem dessas estruturas e produzem elevadas concentrações foliares de metabólitos secundários como forma de proteção. Esses compostos podem ser utilizados na bioprospecção de herbicidas naturais. Dessa forma, objetivamos com este estudo avaliar a fitotoxicidade dos extratos hexânico, acetato etílico e aquoso de folhas jovens de Blepharocalyx salicifolius (Kunth) O. Berg sobre o alongamento de coleóptilos estiolados de Triticum aestivum L. (trigo) e avaliar o potencial fitotóxico do extrato acetato etílico sobre a germinação, crescimento e comprimento das células do metaxilema de Sesamum indicum (gergelim). Os extratos hexânico e acetato etílico inibiram o alongamento dos coleóptilos em todas as concentrações testadas, entretanto os resultados mais promissores foram observados nos fragmentos submetidos ao extrato acetato etílico. Este extrato alterou o tempo médio de germinação e a sincronia das sementes de gergelim, inibiu o crescimento da parte aérea e subterrânea com redução da massa seca das plântulas, levou ao surgimento acentuado de anomalias e causou redução no comprimento médio das células do metaxilema de plântulas de gergelim. Assim, ficou comprovado o potencial fitotóxico dos extratos de folhas jovens de B. salicifolius e a acentuada fitotoxicidade do extrato acetato etílico sobre o desenvolvimento inicial de S. indicum.
Subject(s)
Triticum/drug effects , Triticum/physiology , Plant Leaves/drug effects , Germination/drug effects , Myrtaceae , Hexanes/pharmacology , Acetates/pharmacology , Brazil , Plant Extracts/pharmacology , Plant Roots/growth & development , Plant Roots/drug effects , Plant Leaves/growth & development , Seedlings/drug effects , Herbicides/pharmacologyABSTRACT
The heavy metal resistant bacterium isolated from field soil and identified as Enterobacter sp. RZS5 tolerates a high concentration (100-2000 mM) of various heavy metal ions such as Mn2+, Ni2+, Zn2+, Cu2+, CO2+ and Fe2+ when grown in such environment and produces exopolysaccharides (EPS). Here, we have demonstrated EPS production by Enterobacter sp. RZS5 during 60 h of growth in yeast extract mannitol broth (YEMB). The yield increased by two fold after the addition of 60 M of Ca2+; 50 M of Fe2+ and 60 M of Mg2+ ions in YEMB, and the optimization of physico-chemical parameters. EPS was extracted with 30% (v/v) of isopropanol as against the commonly used 50% (v/v) isopropanol method. EPS-rich broth promoted seed germination, shoot height, root length, number of leaves and chlorophyll content of wheat (Triticum aestivum) and peanut (Arachis hypogaea) seeds. The higher colony-forming unit of Enterobacter sp. in soil inoculated with EPS rich broth of Enterobacter sp. indicated the root colonizing potential and rhizosphere competence of the isolate. The FTIR spectra of the EPS extract confirmed the presence of the functional group characteristics of EPS known to exhibit a high binding affinity towards certain metal ions. This overall growth and vigour in plants along with the effective root colonization, reflected the potential of the isolate as an efficient bio-inoculant in bioremediation.
Subject(s)
Arachis/drug effects , Arachis/growth & development , Arachis/metabolism , Biodegradation, Environmental/drug effects , Chlorophyll/metabolism , Enterobacter/drug effects , Enterobacter/metabolism , Enterobacter/physiology , Germination/drug effects , Host-Pathogen Interactions , Metals, Heavy/metabolism , Metals, Heavy/pharmacology , Plant Leaves/drug effects , Plant Leaves/growth & development , Plant Leaves/metabolism , Plant Roots/growth & development , Plant Roots/microbiology , Plant Shoots/drug effects , Plant Shoots/growth & development , Plant Shoots/metabolism , Polysaccharides, Bacterial/biosynthesis , Polysaccharides, Bacterial/pharmacology , Seeds/drug effects , Seeds/growth & development , Seeds/metabolism , Soil/chemistry , Soil Microbiology , Spectroscopy, Fourier Transform Infrared , Triticum/drug effects , Triticum/growth & developmentABSTRACT
Antioxidant enzymes, besides being involved in various developmental processes, are known to be important for environmental stress tolerance in plants. In this study, the effect of treatment of 2.5 mM putrescine (Put), heat stress (HS -42°C for 2 h) and their combination on the expression and activity of antioxidant enzymes was studied at pre-anthesis in the leaves of two wheat (Triticum aestivum L.) cultivars — HDR77 (thermotolerant) and HD2329 (thermosusceptible). We observed that 2.5 mM Put before HS significantly enhanced the transcript levels of superoxide dismutase (SOD), catalase (CAT), cytoplasmic and peroxisomal ascorbate peroxidase (cAPX, pAPX) in both the cultivars. However, the activities of antioxidant enzymes (SOD, CAT, APX and GR), as well as accumulation of antioxidants (ascorbic acid and total thiol content) were higher in HDR77 than in HD2329 in response to the treatment 2.5 mM Put + HS. No significant change was observed in the proline accumulation in response to HS and combined treatment of 2.5 mM Put + HS. A decrease in the H2O2 accumulation, lipid peroxidation and increase in cell membrane stability (CMS) were observed in response to 2.5 mM Put + HS treatment, as compared to HS treatment alone in both the cultivars; HDR77 was, however, more responsive to 2.5 mM Put + HS treatment. Put (2.5 mM) treatment at pre-anthesis thus modulated the defense mechanism responsible for the thermotolerance capacity of wheat under the heat stress. Elicitors like Put, therefore, need to be further studied for temporarily manipulating the thermotolerance capacity of wheat grown under the field conditions in view of the impending global climate change.
Subject(s)
Heat-Shock Proteins/chemistry , Heat-Shock Response , Oxidative Stress/drug effects , Oxidative Stress/physiology , Plant Leaves/drug effects , Plant Leaves/physiology , Putrescine/administration & dosage , Reactive Oxygen Species/metabolism , Triticum/drug effects , Triticum/physiologyABSTRACT
A phenol-degrading fungus was isolated from crop soils. Molecular characterization (using internal transcribed spacer, translation elongation factor and beta-tubulin gene sequences) and biochemical characterization allowed to identify the fungal strain as Penicillium chrysogenum Thorn ERK1. Phenol degradation was tested at 25 °C under resting mycelium conditions at 6, 30, 60, 200, 350 and 400 mg/l of phenol as the only source of carbon and energy. The time required for complete phenol degradation increased at different initial phenol concentrations. Maximum specific degradation rate (0.89978 mg of phenol/day/mg of dry weight) was obtained at 200 mg/l. Biomass yield decreased at initial phenol concentrations above 60 mg/l. Catechol was identified as an intermediate metabolite by HPLC analysis and catechol dioxygenase activity was detected in plate assays, suggesting that phenol metabolism could occur via ortho fission of catechol. Wheat seeds were used as phototoxicity indicators of phenol degradation products. It was found that these products were not phytotoxic for wheat but highly phytotoxic for phenol. The high specific degradation rates obtained under resting mycelium conditions are considered relevant for practical applications of this fungus in soil decontamination processes.
Un aislamiento fúngico capaz de degradar fenol como única fuente de carbono y energía fue aislado de suelos agrícolas. La caracterización molecular (basada en el empleo de secuencias de espaciadores de transcriptos internos, de factores de la elongación de la traducción y del gen de la beta-tubulina) y la caracterización bioquímica permitieron identificar a esta cepa como Penicillium chrysogenum Thom ERK1. Se estudió la degradación de fenol a 25 °C en cultivos estáticos con 6, 30, 60, 200, 350 y 400 mg/l de fenol inicial. El tiempo requerido para completar la degradación de fenol aumentó al elevarse las concentraciones iniciales de dicho compuesto. La máxima tasa de degradación específica (0,89978 mg de fenol/día/mg de peso seco) se obtuvo con 200 mg/l. El rendimiento en biomasa disminuyó con concentraciones Iniciales de fenol mayores de 60 mg/l. Se identificó al catecol como intermediarlo metabolico por HPLC y se observó actividad de catecol dioxigenasa en placa, lo que sugiere que el metabolismo de degradación del fenol ocurre vía orto fisión del catecol. Se utilizaron semillas de trigo como indicadores de fitotoxicidad de los productos de degradación. Estos productos no fueron fitotóxicos para trigo, mientras que el fenol mostró una alta fitotoxicidad. La alta tasa de degradación específica obtenida en condiciones estáticas resulta de gran interés para la aplicación de este hongo en procesos de descontaminación de suelos.
Subject(s)
Biodegradation, Environmental , Mycelium/metabolism , Penicillium chrysogenum/metabolism , Phenol/metabolism , Biomass , Catalysis , Chromatography, High Pressure Liquid , Carbon/metabolism , Catechols/metabolism , DNA, Fungal/genetics , Fungal Proteins/genetics , Osmolar Concentration , Phylogeny , Penicillium chrysogenum/classification , Penicillium chrysogenum/genetics , Penicillium chrysogenum/isolation & purification , Phenol/toxicity , Sequence Alignment , Sequence Analysis, DNA , Soil Microbiology , Seeds/drug effects , Time Factors , Triticum/drug effects , Tubulin/geneticsABSTRACT
In order to select phytotoxin producing rhizobacteria to control weed plants, twenty five bacterial strains previously isolated from the rhizospheres of various plants were grown in a liquid medium and, after cell removal by centrifugation, the liquid phases were freeze-dried and the products were extracted with ethyl acetate/methanol. The extracts were concentrated to dryness under vacuum and dissolved in water and sucrose solution to be submitted to in vitro assays of lettuce (Lactuca sativa L.) seed germination and wheat (Triticum aestivum L.) coleoptile growth. Although most samples affected coleoptile growth, only those from four strains reduced lettuce seed germination. Two strains of Bacillus cereus, one strain of B. pumilus and one of Stenotrophoonas altophilia were the most promising microorganisms for producing phytotoxin and, consequently, for the development of new weed control products.
Com o objetivo de selecionar rizobactérias produtoras de fitotoxinas para uso no controle de plantas daninhas, vinte e cinco isolados bacterianos previamente obtidos das rizosferas de diferentes plantas foram cultivados em meio líquido e, após remoção das células por centrifugação, as fases líquidas foram liofilizadas e os resíduos obtidos foram submetidos à extração com acetato de etila/metanol. Os extratos foram concentrados sob vácuo até secura e dissolvidos em água e solução de sacarose para serem submetidos a testes in vitro de germinação de sementes de alface (Lactuca sativa L.) e de crescimento de coleóptilos de trigo (Triticum aestivum L.). Embora a maior parte das amostras tenha desfavorecido o crescimento dos coleóptilos de trigo, somente as provenientes de quatro isolados reduziram a germinação das sementes de alface. Dois isolados de Bacillus cereus, um isolado de B. pumilus e um de Stenotrophomonas maltophilia foram os microrganismos mais promissores para a produção de fitotoxinas, com possibilidade de uso no desenvolvimento de novos produtos para o controle de plantas daninhas.
Subject(s)
Bacterial Toxins/pharmacology , Cytotoxins/pharmacology , Gram-Negative Aerobic Rods and Cocci/isolation & purification , Lettuce/drug effects , Rhizosphere , Triticum/drug effects , Bacterial Toxins/biosynthesis , Cytotoxins/biosynthesis , Gram-Negative Aerobic Rods and Cocci/chemistry , Gram-Negative Aerobic Rods and Cocci/metabolism , Lettuce/growth & development , Plant Weeds/drug effects , Plant Weeds/growth & development , Seeds/drug effects , Seeds/growth & development , Triticum/growth & developmentABSTRACT
Single and joint toxicity of chloramphenicol and Hg acting on wheat [Triticum aestivum L.] Chinese cabbage [Brassica campestris L.] and corn [Zea mays L.] were investigated. The results showed positive correlations between root elongation inhibition of three plants and concentrations of pollutants added to soil [P<0.01] in test concentration range. In terms of root elongation, wheat was the most sensitive to toxicity of chloramphenicol with an IC[50] [concentration when 50% plants show inhibition] value as high as 26.8 mg/kg and also was the most sensitive one to the toxicity of Hg with the IC[50] value as high as 300.8 mg/ kg. The toxicity of chloramphenicol to the plants is stronger than that of Hg. Chloramphenicol and Hg had an antagonistic effect on the inhibition of root elongation of the three plants when the concentration of added Hg reached 30 mg/kg. Chloramphenicol and Hg had significantly synergistic effects on the inhibition of root elongation when Hg concentration was up to 200 mg/kg [P<0.05]
Subject(s)
Chloramphenicol/toxicity , Mercury/toxicity , Triticum/drug effects , Plant Roots/drug effectsABSTRACT
Mercury is known to interact with different parts of living systems causing serious biochemical and physiological disorder. In order to know the effect of mercury (Hg2+) ion on chloroplasts, the cell free organelle are incubated in an isotonic buffer medium in presence of mercury ion. The metal ion is found to induce membrane lipid peroxidation, loss of photosynthetic pigments and degradation of proteins. Such degradation brings about a drastic modification of lipid-protein organization of chloroplasts as reflected from a blue shift of absorption peaks and lowering of chlorophyll-a fluorescence intensity. The detrimental effect of Hg2+ ion has been explained in terms of direct binding with lipid-protein complex of photosynthetic membrane. Such a binding of metal ion exposes the lipid-protein complex for an easier entry and attack of reactive oxygen species (ROS) generated during incubation of chloroplasts in light and dark, thereby resulting in higher disorganization, which is evident from cation- induced changes in absorption and emission characteristics of the organelle.
Subject(s)
Absorption , Chloroplasts/drug effects , Chloroplasts/metabolism , Darkness , Lipid Metabolism/drug effects , Lipid Peroxidation/drug effects , Malondialdehyde/metabolism , Mercury/pharmacology , Photosynthesis/drug effects , Pigments, Biological/metabolism , Plant Proteins/chemistry , Plant Proteins/metabolism , Protein Stability/drug effects , Thylakoids/drug effects , Thylakoids/metabolism , Triticum/cytology , Triticum/drug effects , Triticum/metabolismABSTRACT
The experiment was performed to study the seed germination and seedling growth in wheat under the influence of different concentrations of copper. The germination %, plumule and radicle length, and number of lateral roots decreased with increase in copper concentration (5, 25, 50 and 100 mgl(-1)). Total chlorophyll contents declined on 14th day from 1.605 of control to 1.581, 1.242, 1.275 and 1.107 mg g(-1) fresh weight in respective treatments. Similarly, on 21st day the decline in total chlorophyll contents was 1.288, 1.123, 1.077 and 0.985 mg g(-1) fresh weight in respective treatments against 1.724 of control. Likewise the pheophytin contents also declined showing the same pattern. However, carotenoid contents increased in different treatments, ranging between 0.366 to 0.464 mg g(-1) fresh weight in comparison to control (0.328) on 14th day, but showed adverse effects on 21st day as the carotenoid contents decreased in different copper treatments. The activity of amylase was found to be gradually reduced 14th day from 29.73 of control to 27.80, 27.33, 21.86 and 20.00 mg g(-1) and at 21st day from 14.40 of control to 11.46, 11.01, 9.86 and 5.60 mg g(-1) fresh weight with increase in concentrations of copper The catalase activity increased 14th day from 97.33 of control to 134.66, 161.33, 216.00 and 232.00 and on 21st day from 140.00 of control to 245.33, 274.66, 278.66 and 300.66 ml H2O2 hydrolyzed/g fresh weight in different increased concentrations of copper Similarly the peroxidase activity was also increased with increase in copper concentration. Likewise fresh weight and moisture contents decreased with increase in copper concentration. The dry weight was increased with increase in concentration of copper treatment. Total protein contents were initially decreased on 14th day from 80.69 of control to 66.75, 60.41, 56.41 and 48.48 microg/mg and on 21st day 81.37 of control to 67.06, 62.31, 54.92 and 46.47 microg/mg fresh weight in different copper concentrations respectively Sugar contents were significantly decreased in all the doses of copper on both 14th and 21st days i.e. (5.53 of control to 4.76, 3.69, 3.68 and 2.86 microg/mg in different copper treatments on 14th day and 4.81 of control to 4.49, 3.40, 2.79 and 2.15 microg/mg on 21st day respectively.
Subject(s)
Amylases/metabolism , Carbohydrate Metabolism/drug effects , Catalase/metabolism , Chlorophyll/metabolism , Copper/toxicity , Germination/drug effects , Peroxidase/metabolism , Proteins/metabolism , Seedlings/drug effects , Seeds/drug effects , Soil Pollutants/toxicity , Triticum/drug effectsABSTRACT
Induction of defense response against Karnal bunt (KB)by suppressing the pathogenesis was observed upon exogenous application of jasmonic acid (JA)as evident from decrease in the coefficient of infection and overall response value in both susceptible and resistant varieties of wheat. The ultra-structural changes during disease progression showed the signs of programmed cell death (PCD). However, JA strengthened the defense barrier by enhancing the lignifications of cell walls as observed in spikes of both varieties by histochemical analysis. Compared to the plants inoculated with pathogen alone, plants of resistant line (RJP) first treated with JA followed by inoculation with pathogen showed more lignifications and extracellular deposition of other metabolites on cells, which is supposed to prevent mycelial invasions. Contrary to this, susceptible (SJP)lines also showed lignifications but the invasion was more compared to resistant line.Induction of protease activity was higher in resistant variety than its corresponding susceptible variety. The protease activity induced during the colonization of the pathogen and its proliferation inside the host system gets inhibited by JA treatment as demonstrated by the quantitative and in-gel protease assay. The results indicate the role of JA signalling in inhibiting the proteases due to expression of certain protease inhibitor genes. SDS-PAGE analysis shows differential gene expression through induction and/or suppression of different proteins in wheat spikes of resistant and susceptible varieties under the influence of JA. Thus, exogenously applied JA provides the conditioning effect prior to the challenge of infection and induces defense against KB probably by maintaining a critical balance between proteases and protease inhibitors and/or coordinating induction of different families of new proteins.
Subject(s)
Cyclopentanes/pharmacology , Electrophoresis, Polyacrylamide Gel , Gene Expression Regulation, Plant , Immunity, Innate/drug effects , Oxylipins , Peptide Hydrolases/genetics , Plant Diseases/genetics , Plant Growth Regulators/pharmacology , Seeds/drug effects , Signal Transduction , Triticum/drug effectsABSTRACT
In vitro cultures of plant tissues are known to mimic the response of field-grown plants when subjected to stress treatments. This investigation on Triticum aestivum explores the effect of drought stress on somatic embryogenesis and endogenous proline content. Leaf bases were cultured on MS medium supplemented with 2,4-D (10 microM) and different concentrations of PEG (2.5, 5, 7.5%) or mannitol (0.25 and 0.5 M) and also subjected to different periods of aerial drying in the laminar flow for one-day and subsequently transferred to MS basal medium. PEG treatment induced a high percentage (up to 50%) of embryoid formation. However, with mannitol and aerial drying, percentage of embryoid formation decreased with increasing concentrations and duration. After ten days, the endogenous proline content of explants treated with different concentrations of PEG, mannitol and different durations of aerial drying increased with increasing concentration and increasing duration of the treatment, thus, corroborating the role of proline as an osmolyte during stress conditions. Similarly, addition of metals such as cadmium and cobalt caused a reduction in percentage explants depicting embryogenesis. However, when cadmium was employed alone, 22% explants displayed somatic embryogenesis as compared to 54% in 2,4-D treated cultures.
Subject(s)
Adaptation, Physiological/drug effects , Dehydration , Mannitol/pharmacology , Metals, Heavy/pharmacology , Plant Leaves/drug effects , Plant Physiological Phenomena/drug effects , Polyethylene Glycols/pharmacology , Seeds/drug effects , Triticum/drug effectsABSTRACT
In this research, the response of four bread wheat cultivars (Bal-Atilla, Marmara-86, Seyhan-95, and Panda) to different NaCl concentrations (25.6, 51.3, 77.0, 99.4,119.7 mM) were investigated by using callus cultures. In the experiment, callus induction rates (%) and callus weights in solid and liquid MS media, callus weights in liquid MS media with different NaCl concentrations and in liquid MS media free NaCl concentrations, and callus weights and regeneration rates in MS solid media with NaCl concentrations were studied. Callus induction rates and weights were significantly different among genotypes. Callus weights in liquid MS media were higher than those obtained in the MS solid media. Panda cv. had the highest callus weight in the liquid MS media. Callus weights significantly decreased due to increased NaCl stress. Residual effect of NaCl concentrations on Calli weights was significant. Callus weights decreased due to increasing residue effects of NaCl concentrations. There was no cultivar resistance to salinity, high salinity and very high salinity concentrations. However, Panda cv. was more tolerant cultivar at the light salinity concentrations. Gametoclonal regeneration could not be obtained.
Subject(s)
Bread , Culture Media , Culture Techniques , Regeneration/drug effects , Seedlings/drug effects , Sodium Chloride/pharmacology , Triticum/drug effectsABSTRACT
The effect of Cd2+ on growth, photosynthesis and ion relations of hydroponically grown wheat plants was studied in a greenhouse experiment. Four different concentrations of Cd2+ [0, 1, 5 and 10 muM cadmium sulfate] were applied. Root and shoot dry weight, relative growth rate [RGR], net assimilating ratio [NAR] were significantly reduced by 5 and 10 muM Cd. The application of Cd2+ resulted in reduction of photosynthesis and transpiration. Data concerning the accumulation of cadmium in root and shoot as function of time and external cadmium concentration indicated that cadmium content of the shoot was low as compared with that in root. The application of Cd2+ was found to affect the nutrient concentration of root and shoot tissue and their uptake by plant
Subject(s)
Cadmium/pharmacology , Photosynthesis/drug effects , Ions , Triticum/drug effectsABSTRACT
Chromium (Cr) at graded levels when added in sand culture of wheat (T. aestivum L. cv. UP2003) under glasshouse conditions resulted in reduction in biomass, chlorophyll and activities of catalase and peroxidase while enhanced acid phosphatase and ribonuclease activities. Elevated levels of Cr supply significantly reduced the concentration of inorganic phosphorus. With an increase in Cr supply the uptake of chromium also increased significantly in different plant parts especially in roots. Above metabolic lesions due to Cr in wheat provided evidence that the element in nutrient medium if present in excess may be inhibitory to plant growth and development.
Subject(s)
Biomass , Chlorophyll/metabolism , Chromium/metabolism , Dose-Response Relationship, Drug , Triticum/drug effectsABSTRACT
An indirect enzyme immunoassay for detection of as little as 10-50 pmole IAA is described for the first time. The assay is based on the development of highly specific polyclonal antibodies against the carboxyl site of IAA. The binding specificity is nearly as high as the radioimmunoassay and the titre of the specific antibody was also remarkably high (1:40,000 of the primary antibody). Such an easy, rapid, specific and highly sensitive assay would be extremely useful in gaining more information on the mode of action of phytohormones, and their effects on physiological processes.
Subject(s)
Animals , Antibodies , Cholestanols/pharmacology , Cotyledon/drug effects , Enzyme-Linked Immunosorbent Assay , Indoleacetic Acids/analysis , Plant Growth Regulators/analysis , Rabbits , Steroids, Heterocyclic/pharmacology , Triticum/drug effectsABSTRACT
Effect of 100 mM NaCl on seed germination, plumule and radicle elongation and interaction of GA with NaCl were examined in 2 wheat genotypes differing in salt tolerance. NaCl stress reduced seed germination rate equally in both cultivars. However, NaCl-induced reduction in plumule and radicle elongation in Giza 157 [sensitive cultivar] was greater than in Sakha 8. Salinity stress increased accumulation of Na and Cl while it decreased K accumulation in germinating seeds, and more reduction in Giza 157. Gibberellic acid [105 M] partially alleviated the inhibitory effect of NaCl stress on seed germination, plumule and radicle elongation. Gibberellic acid added to NaCl increased K content and decreased Cl and Na accumulation in germination seeds. The effect of salinity stress on germination, ion accumulation and the interaction of gibberellic acid with salinity was discussed