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51.
Benzothiadiazole (BTH) and DL-β-aminobutyric acid (BABA) induced systemic resistance was investigated in susceptible and resistant pea genotypes against Uromyces pisi. Resistance was characterized by reduced infection frequency mainly due to decreases in appressorium formation, stomatal penetration, growth of infection hyphae and haustorium formation. Changes in β-1,3-glucanase, chitinase, phenylalanine ammonia-lyase and peroxidase activities and in total phenolics content, demonstrate that U. pisi resistance is induced by BTH and BABA treatments at early and late stages of the fungal infection process, but that the chemicals operate via different mechanisms. In fact, our study showed that BTH treatment primed the activity of pathogenesis related-proteins such as β-1,3-glucanase, chitinase and peroxidase in both susceptible and resistant genotypes. On the other hand, BABA treatment did not increase the enzymatic activities in the studied genotypes, but significantly increased their total phenolic contents.  相似文献   
52.
The effects of four light intensities (1000 lx, 500 lx, 50 lx, 3 lx) on growth, survival and feeding activity in common sole (Solea solea L.) larvae were studied from 4 to 51 days post hatching (dph). During the pelagic larval stage (4–12 dph), larvae reared at 3 lx showed a lower growth. From 19 onwards, the larvae reared under 3 lx displayed a significant ( 0.05) higher SGR than the other treatments and a higher final weight compared to 1000 lx and 500 lx. Survival rate was higher under intermediate light intensities (500 and 50 lx). Larvae reared at 3 lx displayed a significant delay in the degree of metamorphosis compared to the other treatments, while at 33 dph metamorphosis was completed under all treatments. Histological examination revealed the importance of vision and light in the first feeding of this species, while after metamorphosis, the full development of other sensory organs indicated that feeding activity is also mediated by chemosensory perception. Results indicate that high light intensity seems to be more suitable during the pelagic larvae, while the opposite would ensure better growth from the onset of metamorphosis to the benthic phase.  相似文献   
53.
Domestic cats are preferred models for normal physiology and several human diseases. In the present study feline fetal fluids and membranes were evaluated as possible sources of MSCs. Samples were recovered from 4 pregnant queens after ovarian-hysterectomy. Gestational sacs were separated from uterine wall; after allantoic and amniotic fluids aspiration and chorion-allantois and amniotic membranes separation, all cell lineages were cultured into 25 cm(2) flasks, in DMEM/TCM199, in a 5% CO(2) incubator at 38.5 °C. At passage 3, chondrogenic, osteogenic and adipogenic differentiation ability were evaluated by culturing cell monolayers in differentiating media for 21 days. Cellular characterization with CD90, CD44, CD105, CD73, CD34, CD14, CD45, was performed by flow cytometry. In all samples, adherent fibroblastoid spindle-shaped cells were observed. Positive von Kossa and Alizarin Red staining confirmed osteogenesis. Alcian blue staining of matrix glycosaminoglycans illustrated chondrogenesis, and positive Oil Red O lipid droplets within cell cytoplasm suggested adipogenesis. All cell lines isolated were positive for CD90, CD44, CD105 and negative for CD34, CD14 and CD45; as unexpected and different from human cells, feline cells resulted negative for CD73. Based on this preliminary results, fetal fluids and membranes could represent an alternative sources for mesenchymal stem cells in feline species.  相似文献   
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55.

Purpose

The possibility of using chemical and microbial additives to enhance the phytoextraction of mercury (Hg) and arsenic (As) from a multi-contaminated soil could be very effective, leading to a significant saving in terms of time and costs of the reclamation. The aim of this study was to evaluate the efficacy of the addition of (i) thiosulfate and (ii) metal-tolerant bacteria isolated from the polluted soil having plant growth promotion (PGP) potential to perform As and Hg phytoextraction by Brassica juncea and Lupinus albus.

Materials and methods

A collection of 13 bacterial isolates able to tolerate As and Hg was obtained from the contaminated soil, identified by partial 16S rRNA gene sequencing and tested in vitro for PGP activities. The most promising strains were further tested in vivo for the evaluation of plant growth ability and rhizocompetence on model plants. Pot experiments were conducted in microcosms, with polluted soil vegetated with B. juncea and L. albus. Ammonium thiosulfate and potassium dihydrogen phosphate were used as mobilizing agents, together with a bacterial consortium composed by the most promising PGP isolates.

Results and discussion

Thirteen indigenous metal-tolerant bacterial strains were isolated, and their in vitro characterization highlighted their great potential in assisting the phytoremediation process; most of them tolerated both trace elements and showed, at the same time, multiple PGP traits. The results were confirmed in vivo on model plants and lead to the selection of the most promising PGP strains to be applied in microcosm-scale phytoextraction experiments. Thiosulfate addition significantly increased the mobilization of both elements, promoting bioavailability and phytoextraction. When a selected bacterial consortium was supplemented in addition to thiosulfate, the efficacy of the phytoaccumulation was increased up to 85 % for As and up to 45 % for Hg.

Conclusions

The use of the common fertilizer thiosulfate appeared to have great potential in phytoextraction practices since it was able to facilitate the uptake by plants of both Hg and As. Moreover, the application of a consortium of indigenous PGP bacteria (PGPB) produced a further positive effect on the plant biomass, supporting and enhancing the phytoextraction strategy, thus demonstrating their potential in a microbe-assisted phytoremediation intervention.
  相似文献   
56.
Vineyard management practices to enhance soil conservation principally focus on increasing carbon (C) input, whereas mitigating impacts of disturbance through reduced tillage has been rarely considered. Furthermore, information is lacking on the effects of soil management practices adopted in the under-vine zone on soil conservation. In this work, we evaluated the long-term effects (22 years) of alley with a sown cover crop and no-tillage (S + NT), alley with a sown cover crop and tillage (S + T), and under-vine zone with no vegetation and tillage (UV) on soil organic matter (SOM), microbial activity, aggregate stability, and their mutual interactions in a California vineyard in USA. Vegetation biomass, microbial biomass and activity, organic C and nitrogen (N) pools, and SOM size fractionation and aggregate stability were analysed. Soil characteristics only partially reflected the differences in vegetation biomass input. Organic C and N pools and microbial biomass/activity in S + NT were higher than those in S + T, while the values in UV were intermediate between the other two treatments. Furthermore, S + NT also exhibited higher particulate organic matter C in soil. No differences were found in POM C between S + T and UV, but the POM fraction in S + T was characterized by fresher material. Aggregate stability was decreased in the order: S + NT > UV > S + T. Tillage, even if shallow and performed infrequently, had a negative effect on organic C and N pools and aggregate stability. Consequently, the combination of a sown cover crop and reduced tillage still limited SOM accumulation and reduced aggregate stability in the surface soil layer of vineyards, suggesting relatively lower resistance of soils to erosion compared to no-till systems.  相似文献   
57.
This case report describes the clinical and diagnostic imaging findings, treatment and outcomes of a 15-day-old Thoroughbred foal referred for the evaluation of severe left hindlimb lameness of 8 days' duration. Radiographic examination of the left hindlimb and transcutaneous ultrasonographic examination of the pelvis were unremarkable. A computed tomographic (CT) examination was performed to investigate the proximal aspect of the limb and the pelvis; CT scans of the thorax were also acquired. In this case, CT images allowed detection of a closed, slightly displaced, oblique wedge-like fracture of the left caudal ramus of the pubis and medial ramus of the ischium, allowing an accurate diagnosis to guide appropriate treatment and prognostication. The foal was treated with anti-inflammatory drugs and box-rest. A follow-up by telephone interview with the trainer 3 years later revealed that the horse is in full athletic activity without any residual gait alteration related to the pelvic fracture.  相似文献   
58.
Sanguinarine (SA), a phytobiotic from Sanguinaria Canadensis, has been demonstrated to inhibit vessel growth. Current restrictions on the use of antibiotic growth promoters have motivated addition of this alkaloid as a naturally appetizing feed additive for farm animals. However, concern may araise since angiogenesis is a fundamental event in ovarian follicle growth. Therefore, the aim of this study was to evaluate the potential negative role of SA in follicular angiogenesis. For this purpose, we studied the effect of 300 nM SA on the production of vascular endothelial growth factor (VEGF) by swine granulosa cells from follicles >5 mm and on the activation of Akt, the main effector of the VEGF signalling pathway. In addition, the potential interference of SA in vessel development was tested in an in vitro angiogenesis bioassay. SA inhibited both VEGF production and VEGF-induced Akt activation in swine granulosa cells. Moreover, it was able to block vessel growth induced by VEGF. Taken together, our results suggest that SA could be detrimental to follicular angiogenesis, and therefore supplementation of feed with this alkaloid should be carefully considered.  相似文献   
59.
60.
Soil aggregation and organic matter (OM) conservation are important in the prevention of land degradation. Aggregation processes and OM turnover influence each other and depend on the characteristics of both minerals and organic pools. We assessed the relative importance of the organic and mineral phases at the macroaggregate and colloidal scale in two soils (CHL and SRP, chlorite and serpentine‐rich, respectively) where Mg‐silicates dominated, by incubating them with a relatively degraded and oxidized organic fraction, that is the humic acids (HAs) extracted from the organic horizons of both CHL and SRP. The HA from SRP were more aromatic and richer in phenolic groups, whereas HA from CHL were N‐richer, more aliphatic and richer in carboxyl groups. The SRP soil formed larger amounts of macroaggregates, more stable than in CHL. At the colloidal scale, SRP was more flocculated and clay had a lower electrophoretic mobility than CHL. HA enhanced aggregate formation in both samples but improved aggregate stability only in CHL. In CHL, slight differences in electrophoretic mobility were visible, while in SRP, differences were more pronounced, with a point of zero charge at lower pH and larger hydrodynamic diameter. The abundance of Mg in SRP may have favoured the formation of weaker outer‐sphere interactions and the release of clay‐HA associations upon water dispersion, while in CHL Ca formed more stable bonds with HA. In SRP, ligand exchange reactions can be ruled out, conversely to the dominant bonding mechanism occurring in Al‐silicate dominated soils, with important consequences on the release of OM‐loaded clay particles. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
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