The role of N form supply for PGPM‐host plant interactions in maize     

Isaac Kwadwo Mpanga  Ninoska Gomez-Genao  Narges Moradtalab  Daniel Wanke  Victor Chrobaczek  Aneesh Ahmed  Saskia Windisch  Joerg Geistlinger  Fatema Binte Hafiz  Frank Walker  Uwe Ludewig  Günter Neumann 《植物养料与土壤学杂志》2019,182(6):908-920

The form of nitrogen (N) supply has a significant impact on rhizosphere chemistry and root growth responses of higher plants. The respective effects are also employed as management options to improve nutrient acquisition and to minimize nutrient losses in cropping systems. However, surprisingly little is known concerning the interactions with rhizosphere biota. In this study, we investigated the effects of selected bacterial and fungal inoculants with proven plant growth‐promoting and phosphate (P)‐solubilizing potential (plant growth‐promoting microorganisms, PGPM) in maize with nitrate or stabilized ammonium supply, on soils with limited P availability and sparingly soluble rock phosphate (Rock‐P) applied as P fertilizer. The combination of the bacterial inoculants Pseudomonas sp. DSMZ 13134 (Proradix) and Bacillus amyloliquefaciens FZB42 with ammonium sulphate fertilization, stabilized with the nitrification inhibitor 3,4‐dimethylpyrazole‐phosphate (DMPP), resulted in a superior shoot biomass production (79–111%) and shoot P accumulation (109–235%) as compared with nitrate supply. This effect could be partially attributed to (1) ammonium‐induced rhizosphere acidification via increased root extrusion of protons, (2) promotion of root hair elongation, and (3) increased shoot concentrations of hormonal growth regulators (indole‐3‐acetic acid, zeatin, gibberellic acid). The effects, induced by the microbial inoculants were mainly related to increased root length development (43–44%), associated with a 60% increase in auxin production potential. No inoculant effects were detected on root hair elongation or on chemical modifications of the rhizosphere involved in P solubilisation, such as rhizosphere acidification, release of carboxylates or secretory phosphohydrolases. However, the ammonium‐induced stimulation of root hair elongation increased preferential sites for root colonization by the selected inoculants, which may explain the increase in rhizosphere abundance of PGPMs, exemplarily recorded for the fungal inoculant Trichoderma harzianum OMG16 (210%). The presented data suggest a network of positive interactions between stabilized ammonium fertilization and plant growth‐promoting functions of various bacterial and fungal PGPM inoculants. This offers perspectives to increase the efficiency and the reproducibility of PGPM‐assisted fertilization strategies.  相似文献   

Trace and major element contents,microbial communities,and enzymatic activities of urban soils of Marrakech city along an anthropization gradient     

Naylo  Ahmed  Almeida Pereira  Sofia I.  Benidire  Leila  El Khalil  Hicham  Castro  Paula M. L.  Ouvrard  Stéphanie  Schwartz  Christophe  Boularbah  Ali 《Journal of Soils and Sediments》2019,19(5):2153-2165

Journal of Soils and Sediments - Due to their close proximity with the population, urban soils are extensively affected by human activities that release considerable technogenic inputs resulting in...  相似文献   

Pathological and biochemical studies on experimental hypothyroidism in growing lambs     

Sokkar SM  Soror AH  Ahmed YF  Ezzo OH  Hamouda MA 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2000,47(9):641-652

Secondary iodine deficiency was experimentally produced in growing male lambs by oral administration of 50 mg/kg bodyweight of Thiourea daily for 3.5 months. At the end of the experiment the animals became weak, emaciated, anaemic, significantly reduced in body weight with facial oedema and alopecia at thigh, legs and abdomen. The clinical analysis showed significant reduction in erythrocyte and leucocyte numbers and in levels of triiodothyronine and testosterone at the end of the experiment. The histopathological picture of the thyroid gland revealed hyperplasia of the follicle-lining epithelial cells which project into the lumen. The lumens of the follicles are devoid of colloid. The testes showed ill-developed small, empty seminiferous tubulcs. In the liver, the hepatocytes showed degeneration and vacuolation with proliferation of Kupffer cells, which contain haemosiderin pigment. The kidney showed glomerular lipidosis with accumulation of haemosiderin pigment in the cytoplasm of the renal tubules. Hyperkeratosis of the epidermis associated with excessive keratin formation within the hair follicles was detected. In conclusion, deficiency of iodine causes hypothyroidism which leads to retardation of growth, reduced wool production and interferes with sexual maturity of growing male lambs.  相似文献   

Observations made during a natural outbreak of aegyptianellosis in chickens     

A A Ahmed  M K Soliman 《Avian diseases》1966,10(4):390-393

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In vitro culture of mouse preantral follicles using membrane inserts and developmental competence of in vitro ovulated oocytes   总被引：3，自引：0，他引：3  

Adam AA  Takahashi Y  Katagiri S  Nagano M 《The Journal of reproduction and development》2004,50(5):579-586

To develop a reliable follicle culture system, mouse preantral follicles 150-200 microm in diameter were cultured individually for 5 or 6 days in membrane inserts or in droplets, and then induced to ovulate with hCG (Experiment 1). The nuclear maturation and developmental competence of the oocytes that ovulated from the follicles cultured in inserts were determined (Experiment 2). There was no significant difference between the two culture systems in the survival rate (83 and 77%). However, follicles cultured in inserts showed a higher ovulation rate (63%) than those cultured in droplets (39%, P<0.05). About 80% of the oocytes that ovulated from the follicles cultured in inserts were at the metaphase II stage. After in vitro fertilization, 75 and 48% of in vitro ovulated oocytes cleaved and developed into blastocysts, respectively. These results demonstrate that the insert culture system is superior to the droplet culture system in terms of follicular growth and ovulation, and can be used to investigate the growth and ovulation of follicles in vitro.  相似文献   

Screening study for potential lead compounds for natural product-based fungicides: I. Synthesis and in vitro evaluation of coumarins against Botrytis cinerea     

Daoubi M  Durán-Patrón R  Hmamouchi M  Hernández-Galán R  Benharref A  Collado IG 《Pest management science》2004,60(9):927-932

An efficient, one-pot synthesis of angular and linear dihydropyranocoumarins, along with C-6 and C-8 prenylated coumarins is reported. These compounds, together with single- and furanocoumarins, were tested for their potential antifungal activity against the phytopathogen Botrytis cinerea Pers ex Fr. The results show that furanocoumarins may be able to control the fungus B cinerea.  相似文献   

Feline leptin: immunogenic and biological activities of the recombinant protein, and its measurement by ELISA     

Shibata H  Sasaki N  Honjoh T  Ohishi I  Takiguchi M  Ishioka K  Ahmed M  Soliman M  Kimura K  Saito M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(11):1207-1211

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Immunologic analysis of blood samples obtained from horses and stored for twenty-four hours     

Witonsky S  Gogal RM  Buechner-Maxwell V  Ahmed SA 《American journal of veterinary research》2003,64(8):1003-1009

OBJECTIVE: To determine whether immune function can be accurately assessed in blood samples obtained from horses and refrigerated overnight and whether a nonradioactive lymphocyte proliferation assay can be used to evaluate samples obtained from horses. SAMPLE POPULATION: 224 blood samples from 28 clinically normal adult horses. PROCEDURE: Heparinized blood samples were collected. Each sample was divided into 2 equal aliquots. One aliquot was refrigerated overnight to simulate overnight shipping of blood samples, and the other aliquot was evaluated on the day of blood collection. Lymphocytes were isolated and enumerated by use of a modified single-gradient procedure. Cell viability and function were assessed by use of cytologic examination, flow cytometry, and mitogen-induced proliferation assays. Lymphocyte proliferation in response to T- and B-cell mitogens was measured by use of [3H]-thymidine incorporation and a nonradioactive lymphocyte proliferation assay. RESULTS: Lymphocytes refrigerated for up to 24 hours continued to be acceptable for use in immunologic analysis on the basis that they maintained viability and did not have significant alterations in lymphocyte subsets, except for CD8, when compared with freshly isolated lymphocytes. Furthermore, results for mitogen-induced lymphocyte proliferation assays were also comparable between fresh and refrigerated aliquots. CONDUSIONS AND CLINICAL RELEVANCE: The nonradioactive lymphocyte proliferation assay is a reliable alternative to [3H]-thymidine assay for assessing proliferation of equine lymphocytes. Collectively, our results imply that blood samples refrigerated and shipped ovenight to a laboratory can be used to perform cellular-immune assays; results of those assays would enhance a clinician's diagnostic abilities to monitor the efficacy of treatment.  相似文献   

Production and purification of ovine anti-tetanus antibody   总被引：1，自引：0，他引：1  

Redwan el-RM  Khalil A  El-Dardiri ZZ 《Comparative immunology, microbiology and infectious diseases》2005,28(3):167-176

We used the ovine as bioreactor for the production and optimization of anti-tetanus toxin antibody. Four female sheep were immunized with human tetanus vaccine (TT-alum) every two weeks for 16 weeks, after which serum was collected and its titer was estimated by ELISA. The highest titer obtained was 39,000 IU ml-1. To optimize a purification protocol for ovine anti-tetanus toxin, we used four procedures; weak anion (DEAE-Sephadex), weak cation (CM-Sephadex), ammonium sulfate precipitation alone or in combination with caprylic acid. Fifty percent saturation with ammonium sulfate combined with caprylic acid gave us the highest yield of protein with specific activity and the purest Fab product.  相似文献   

Phytotherapeutic effects of Echinacea purpurea in gamma-irradiated mice     

Amira M. K. Abouelella  Yasser E. Shahein  Sameh S. Tawfik  Ahmed M. Zahran 《Journal of veterinary science (Suw?n-si, Korea)》2007,8(4):341-351

Echinacea (E.) purpurea herb is commonly known as the purple coneflower, red sunflower and rudbeckia. In this paper, we report the curative efficacy of an Echinacea extract in γ-irradiated mice. E. purpurea was given to male mice that were divided into five groups (control, treated, irradiated, treated before irradiation & treated after irradiation) at a dose of 30 mg/kg body weight for 2 weeks before and after irradiation with 3 Gy of γ-rays. The results reflected the detrimental reduction effects of γ-rays on peripheral blood hemoglobin and the levels of red blood cells, differential white blood cells, and bone marrow cells. The thiobarbituric acid-reactive substances (TBARs) level, Superoxide dismutase (SOD) and glutathione peroxidase (GSPx) activities and DNA fragmentation were also investigated. FT-Raman spectroscopy was used to explore the structural changes in liver tissues. Significant changes were observed in the microenvironment of the major constituents, including tyrosine and protein secondary structures. E. purpurea administration significantly ameliorated all estimated parameters. The radio-protection effectiveness was similar to the radio-recovery curativeness in comparison to the control group in most of the tested parameters. The radio-protection efficiency was greater than the radio-recovery in hemoglobin level during the first two weeks, in lymphoid cell count and TBARs level at the fourth week and in SOD activity during the first two weeks, as compared to the levels of these parameters in the control group.  相似文献