Evaluation of the role of the endo-β-(1,4)-glucanase gene FaEG3 in strawberry fruit softening

In strawberry, Fragaria × ananassa Duch., fruit, two different endo-β-1,4-glucanase genes, FaEG1 and FaEG3, also named Cel1 and Cel2, are expressed during the softening process that occurs during fruit ripening. It has also been suggested that FaEG3, which contains a putative cellulose-binding domain, could play a key role in fruit development, since previous attempts to down-regulate this gene through transgenesis have been unsuccessful. In this investigation, we obtained transgenic strawberry plants containing an antisense sequence of the FaEG3 gene under the control of the 35S promoter. Ripened fruit from transgenic lines (Acel lines) showed large variation in FaEG3 silencing, but fruit firmness was similar to control fruit in all the lines. Two Acel lines showing almost 95% reductions in FaEG3 mRNA levels were selected for further study. In these lines, FaEG3 down-regulation was high, from 78 to 95%, at all fruit developmental stages, whereas FaEG1 was only slightly suppressed. In spite of the high FaEG3 silencing achieved, EGase activity was not modified in ripe fruit. At the cell wall level, walls from transgenic ripe fruit contained a significantly higher amount of the 4 M KOH fraction, which is enriched in hemicellulosic polymers. The analysis of this fraction by size exclusion chromatography showed that transgenic cell walls contained a smaller amount of higher molecular mass polymers than controls. Altogether, these results indicate that FaEG3 does not play a key role either in fruit development or fruit softening. However, its silencing affects the amount and, in a minor way, the size of hemicellulosic polymers.     

Interaction dynamics between a contaminated dredged sediment and extracting solutions of different nature

Purpose

The purpose of this work is to study the dynamics between the matrix of a contaminated marine sediment, its contaminants and various desorbing solutions by means of equilibrium tests, sedimentation trials and zeta potential, with the focus on assessing optimum enhancing solutions for decontamination purposes.

Materials and methods

The sediment samples were analysed to determine their physico-chemical characteristics: particle size distribution, solids concentration, total organic carbon (TOC), content of heavy metals, organic contaminants, mineralogical phases, zeta potential and buffer capacity. Twelve extracting solutions of different nature were used for equilibrium tests, in which the dynamic behaviour of the sediment was evaluated. Elemental analysis was carried out for the sediment samples and the solutions before and after the tests.

Results and discussion

The sediment was mainly composed of clay and lime, with a high content of iron, which has a strong influence on sorption-desorption processes. The sediment had a considerable buffer capacity at low and high pH values. The desorption of the metals was not proportional to pH. The highest decrease in the concentration of metals from the sediment was obtained with 0.2 M ethylenediaminetetra-acetic acid (EDTA) and 1 M nitric acid, while the lowest degree of metal extraction occurred in pure water and potassium iodide (KI).

Conclusions

The most important parameters for contaminant release were complexation ability of the solution for the sediment components and pH of the solution. A promising design for the remediation treatment for the investigated sediment includes complexation and strong acid agents.

     

Correction to: Interaction dynamics between a contaminated dredged sediment and extracting solutions of different nature

Journal of Soils and Sediments - Figure 4 is not correct in the PDF format of the originally published article. Please note that in the HTML or online format, the image is correct.     

Bronchial carcinoma in a red-shouldered hawk (Buteo lineatus)

Respiratory neoplasms are rare in birds. This report describes carcinoma of the bronchial epithelium in a red-shouldered hawk (Buteo lineatus) that presented with weakness and lethargy lasting 4 days that progressed to seizures. Grossly, the caudal air sac and coelomic cavity contained approximately 15 ml of dark brown cloudy fluid that displaced the intestines cranially. Nodular plaques were present on the viscera and air sacs. Microscopic examination of tissues revealed a mass that expanded the bronchial lumen and was composed of papillary proliferations of rows of small cuboidal epithelial cells that were small and uniform in size with a low mitotic index. Metastases were present on the surfaces of caudal air sac, kidney, and multifocal peritoneal surfaces of the coelomic cavity. Clinical signs were most likely the result of West Nile virus infection, which was confirmed by immunohistochemistry of brain tissue.     

Body wall defects and amniotic band syndrome in pig (Sus scrofa domesticus)

The amniotic band syndrome is a congenital condition. It is characterized by the presence of fibrous amniotic bands that may entangle or entrap different foetal parts in utero, resulting in deformation, malformation or disruption. We report on a female piglet presenting amniotic band adherences in the right abdominal flank, several body wall defects (gastroschisis, abdominoschisis with omphalocele), severe scoliosis, anomalous umbilical cord with single umbilical artery, anal atresia, anomalous liver and absent gall bladder, hypoplastic genitalia, ankylosis and arthrogryposis in pelvic limbs, and bilateral patellar agenesia. The ethiopatogenia is discussed, as well as the comparative and embryological implications.     

Preliminary evidence of the seroprevalence and risk factors associated with Chlamydia abortus infection in goats on the Canary Islands,Spain

Tropical Animal Health and Production - The aims of this cross-sectional study were to estimate the prevalence of IgG antibodies against Chlamydia abortus, the cause of enzootic abortion, in goats...     

NUTRIENT REQUIREMENTS OF CHAMAEROPS HUMILIS L. AND WASHINGTONIA ROBUSTA H. WENDL PALM TREES AND THEIR LONG-TERM NUTRITIONAL RESPONSES TO SALINITY

The ornamental value of plants used in semiarid areas can be improved by knowledge of their required nutrients and of their nutritional responses under saline conditions. We present a long-term study concerning the nutritional status in Chamaerops humilis and Washingtonia robusta. Two-year-old plants were grown for two years outdoors in pots using water with electrical conductivity values of 2 (control) or 8 dS m^?1 (saline conditions). Nutrient specific absorption rates and leaf nutrient transport rates were estimated by fitting a Richards function regression. We suggest fertilizing C. humilis and W. robusta plants with nitrogen (N): phosphorus pentoxide (P₂O₅): dipotassium oxide (K₂O) ratios of 4:1:5 and 5:1:3, respectively. Diagnosis and Recommendation Integrated System (DRIS) and Plant Analysis with Standardized Scores (PASS) norms were also evaluated. PASS norms provided better nutritional diagnosis than DRIS norms. In saline conditions, PASS-INI (Independent nutrient index) pointed to a deficiency (C. humilis and of nitrogen in W. robusta.     

Application of biotechnological tools to Quercus improvement

The genus Quercus, which belongs to the family Fagaceae, is native to the northern hemisphere and includes deciduous and evergreen species. The trees of the different species are very important from both economic and ecological perspectives. Application of new technological approaches (which span the fields of plant developmental biology, genetic transformation, conservation of elite germplasm and discovery of genes associated with complex multigenic traits) to these long-rotation hardwoods may be of interest for accelerating tree improvement programs. This review provides a summary of the advances made in the application of biotechnological tools to specific oak species. Significant progress has been made in the area of clonal propagation via organogenesis and somatic embryogenesis (SE). Standardized procedures have been developed for micropropagating the most important European (Q. robur, Q. petarea, Q. suber) and American (Q. alba, Q. bicolor, Q. rubra) oaks by axillary shoot growth. Although regenerated plantlets are grown in experimental trials, large-scale propagation of oak species has not been carried out. The induction of SE in oaks from juvenile explants is generally not problematic, although the use of explants other than zygotic embryos is much less efficient. During the last decade, enormous advances have been made in inducing SE from selected adult trees, mainly specimens of pedunculate oak (Q. robur) and cork oak (Q. suber). Advances in the understanding of the maturation and germination steps are required for better use of embryogenic process in clonal forestry. Quercus species are late-maturing and late-flowering, exhibit irregular seed set, and produce seeds that are recalcitrant to storage by conventional procedures. Vitrification-based cryopreservation techniques were used successfully in somatic embryos of pedunculate oak and cork oak, and an applied genbank of cork oak selected genotypes is now under development. The feasibility of genetic transformation of pedunculate oak and cork oak somatic embryos by means of co-culture techniques with several strains of Agrobacterium tumefaciens has also been demonstrated. To date, most research on the genomics of Quercus species has concerned population genetics. Approaches using functional genomics to examine the molecular and cellular mechanisms that control organogenesis and or somatic embryogenesis are still scarce, and efforts on the isolation and characterization of genes related to other specific traits should be intensified in the near future, as this would help improve the practical application of clonal forestry in recalcitrant species such as oaks.     

Plant Phenology Influences the Effect of Mycorrhizal Fungi on the Development of Verticillium-induced Wilt in Pepper

Verticillium dahliae alters water status and consequently, growth and production of pepper plants. On the other hand, arbuscular mycorrhizal fungi (AMF) can reduce damage caused by specific soil-borne plant pathogens and improve drought resistance of pepper. Therefore, one objective of this research was to assess if AMF can modify the development of Verticillium-wilt in pepper plants. A second objective was to study the influence of plant phenology at the moment when V. dahliae was inoculated on the possible biocontrol of the disease by AMF. Results suggested that AMF reduce the deleterious effect of V. dahliae on pepper growth and yield. However, bioprotection against Verticillium-wilt was conditioned by plant phenology at the moment of pathogen attack. The highest efficacy of AMF occurred when V. dahliae was inoculated during the vegetative stage of plants. AMF allowed leaf relative water content to be maintained for longer and delayed both the appearance of disease symptoms and the decrease of photosynthesis in Verticillium-inoculated plants. These benefits on plant physiology increased pepper yield.     

Characterization of pathogen-specific expression of host immune response genes in Anaplasma and Mycobacterium species infected ruminants

Anaplasma and Mycobacterium species are among the most prevalent bacterial pathogens in European red deer (Cervus elaphus) in south-central Spain and are known to modify gene expression in ruminants. In this study, we used microarray hybridization and real-time RT-PCR analyses to characterize global gene expression profiles in red deer in response to Anaplasma ovis and A. ovis/Mycobacterium bovis/Mycobacterium avium sub. paratuberculosis (MAP) infections, compare the expression of immune response genes between red deer infected with A. ovis, M. bovis and A. ovis/M. bovis/MAP, and characterize the differential expression of immune response genes identified in red deer in cattle infected with M. bovis and Anaplasma marginale. Global gene differential expression in A. ovis- and A. ovis/M. bovis/MAP-infected deer resulted in the modification of common and pathogen-specific cellular biological processes. The differential expression of host immune response genes showed pathogen and host-specific signatures and the effect of infection with multiple pathogens on deer immune response. These results suggested that intracellular bacteria from Anaplasma and Mycobacterium genera produce similar genes expression patterns in infected ruminants. However, pathogen and host-specific differences could contribute to disease diagnosis and treatment in ruminants.