Immunological characteristics of experimental murine infection with Leishmania (Leishmania) amazonensis

The murine models of Leishmania infection are well-studied and suitable models for studying this disease, which, despite its incidence of nearly 2 million new cases worldwide per year and its prevalence of 12 million cases, has been a somewhat neglected disease. Data obtained using such models are important for a better understanding of the disease in humans due to similarities in physiology and the advantage provided by the uniform infection profile within each mouse strain. In this review, we focus on studies of experimental murine infection with Leishmania (Leishmania) amazonensis, a species that has been associated with infections exhibiting various clinical features in humans. Mainly, we point out and discuss reports on: the effects of variations of the inoculum (such as strain, site, and size) in the establishment and development of the infection; characteristics of the infection in distinct mouse strains; and, the effects and subversions of the infection on components of the host innate and adaptive immune responses. The results obtained in these studies show that L. (L.) amazonensis infection in mice presents some unique features and immunoregulatory mechanisms, making it an interesting model for obtaining further knowledge of potential drugs targets and immunotherapy in Leishmania infection.     

The pine reproductive process in temperate and tropical regions

Our knowledge of the pine reproductive process is confined to the developmental stages and time relations in a particular species. Lacking in the literature is a comparative analysis from a broader perspective such as pines from temperate versus tropical regions. Also, important information that may have beneficial implications for pine breeding and management purposes may be missed by going with a single generalized reproductive cycle model which is usually derived from well-studied northern temperate species. Detailed developmental analysis of the reproductive process is necessary, particularly for tropical pines where information is limited. Most pines undergo a reproductive cycle that spans three calendar years with two dormant periods. In temperate pines, many of the stages that are initiated by fall generally come to a halt during the winter and development resumes in spring of the following year. In tropical pines, reproductive development appears to be generally a continuous process characterized by a gradual rate of development with indistinct first dormant period. The distinct first dormant period in north temperate pines serves to synchronize pollen release and seed-cone receptivity which results in higher pollination success and seed production. Tropical pines exhibit asynchrony in pollen release and thus has extended pollination period. Relatively less pollen are available which results in lower pollination success and seed set. Interestingly, since asynchrony may enhance cross-pollination, tropical pines might benefit from this through the capture of genetic diversity. The length of the second dormant period is generally the same in temperate and tropical pines which indicates strong genetic control.     

Relationships between an Italian Strawberry Ecotype and its Ancestor using RAPD Markers

Random-amplified polymorphic DNA (RAPD) markers were used to evaluate genetic variability among populations of an Italian strawberry ecotype, and to determinate genetic relationships between genotypes and their putative ancestor. A total of 65 selections and one cultivar ‘Madame Moutot’ (MM), were analysed to evaluate genetic variability present in Etna mountain area and to confirm as MM was one of the cultivars that originated the ecotype. A total of 222 RAPD markers was obtained using 16 decamer primers and 6 longer primers, 90.8% of the markers obtained by selected primers resulted polymorphic at least within analysed genotypes. RAPDs were used to calculate genetic similarity coefficients and to generate dendrograms representing genetic relationships among genotypes analysed. Cluster analysis displays as RAPD polymorphisms were able to characterize the genotype variability among closely related groups. The data show as MM could be considered the ancestral genotypes introduced in that area. The results obtained confirm that RAPD markers could be used as reliable markers to perform phylogenetic studies in Fragaria×ananassa Duch. ex Rozier. Giuseppe Bertino and Piero Spada - Coauthor involved in genotype selection and field management     

Identification of vaccine candidates against serogroup B meningococcus by whole-genome sequencing

Neisseria meningitidis is a major cause of bacterial septicemia and meningitis. Sequence variation of surface-exposed proteins and cross-reactivity of the serogroup B capsular polysaccharide with human tissues have hampered efforts to develop a successful vaccine. To overcome these obstacles, the entire genome sequence of a virulent serogroup B strain (MC58) was used to identify vaccine candidates. A total of 350 candidate antigens were expressed in Escherichia coli, purified, and used to immunize mice. The sera allowed the identification of proteins that are surface exposed, that are conserved in sequence across a range of strains, and that induce a bactericidal antibody response, a property known to correlate with vaccine efficacy in humans.     

Effects of Genotype and Environment on Phenolic Acids Content and Total Antioxidant Capacity in Durum Wheat

In cereals, phenolic acid (PA) content and total antioxidant capacity (TAC) may have a wide range of variability, probably because of several factors influencing the occurrence of grain antioxidants, which include genotype, environment, and their possible interactions. However, only a few studies have investigated the influence of these factors on durum wheat. In the present study, we investigated the impact of the genetic and environmental factors on the profile and content of PAs occurring as soluble free, soluble conjugated, and insoluble bound compounds, as well as on the TAC level, in three genotypes of durum wheat grown in three different Italian agroclimatic areas during two crop years. The results show that genotype, environment, and crop year have highly significant effects on TAC levels and on PA contents. In particular, TAC and free PAs are most influenced by year, whereas conjugated and bound PAs are most influenced by environment × year and genotype, respectively. Therefore, it is evidenced that genetic and environmental factors affect the antioxidant activity and the content of the three forms of PAs in durum wheat to different extents.     

Identification and quantification of phenolic compounds in grapes by HPLC-PDA-ESI-MS on a semimicro separation scale

Reversed phase high performance liquid chromatography (RP-HPLC) on a semimicro separation scale was employed to develop a straightforward method for the simultaneous separation, identification, and quantification of phenolic compounds occurring in whole berries of Vitis vinifera, which comprise phenolic acids, flavonols, catechins, stilbenes, and anthocyanins. A C-18 narrow bore column of 150 x 2.0 mm I.D. and a semimicro photodiode array detector (PDA) cell of 2.5 microL, in conjunction with a mass spectrometry detector equipped with an electrospray ionization source (ESI-MS) to confirm peak identification, were employed. The C-18 narrow bore column was eluted by a multisegment gradient of increasing concentration of acetonitrile in water-formic acid solution that was optimized on the basis of the results of a study carried out to evaluate the influence of mobile phase composition and gradient shape on separation performance and detection sensitivity by ESI-MS. The identification of individual phenolic compounds was performed on the basis of their retention times and both UV-visible and mass spectra, acquired by a mass spectrometer (MS) equipped with an electrospray ionization (ESI) source, employed in conjunction with the PDA detector. Libraries comprising retention times, UV-visible, and mass spectra for major phenolic compounds expected in grape berries were made by subjecting solutions of each phenolic standard to the optimized RP-HPLC method. Quantification of individual compounds was performed by the external standard method using a six point regression graph of the UV-visible absorption data collected at the wavelength of maximum absorbance of each analyte determined by the PDA spectra. The RP-HPLC method was validated in terms of linearity of calibration graphs, limits of detection, limits of quantification, repeatability, and accuracy, which was evaluated by a recovery study. The developed method was successfully applied to identify the phenolic compounds occurring in the whole berries of nine red and one white grape of different varieties of Vitis vinifera, comprising some autochthonous varieties of south Italy such as Aglianico, Malvasia Nera, Uva di Troia, Negroamaro, Primitivo, and Susumaniello. Large differences in the content of phenolic compounds was found in the investigated grape varieties. As expected, only glycosilated flavonols were quantified, and the total amount of these compounds was higher in the whole berries of red grapes than in the white Moscato, where the most abundant phenolic compound was quercetin 3-O-glucoside. In almost all samples, the most and least abundant anthocyanins were malvidin 3-O-glucoside and cyanidin 3-O-glucoside, respectively, with the exception of Uva di Troia where the least abundant anthocyanin was delphinidin 3-O-glucoside.     

<Emphasis Type="Italic">Urochloa ruziziensis</Emphasis> cover crop increases the cycling of soil inositol phosphates

Ruzigrass (Urochloa ruziziensis) is a cover crop that is commonly used in Brazil and exudes high concentrations of organic acids from its roots, and is therefore expected to mobilize soil organic P such as inositol phosphates. However, it is not known if this can occur only under P deficient conditions. Specifically, we aimed to test the hypothesis that the degradation of inositol phosphates is increased by growing ruzigrass at two different P levels. To investigate this, we studied soil organic P in a 9-year-old field experiment, with treatments consisting of ruzigrass or fallow during the soybean (Glycine max) off-season, with or without P addition. Organic P was extracted in NaOH-EDTA, followed by colorimetric quantification of organic P hydrolysable by phytase, and myo-inositol hexakisphosphate by hypobromite oxidation and HPLC separation. Ruzigrass dry matter yield increased by about 80% with P application. Ruzigrass reduced the concentration of phytase labile P and myo-inositol hexakisphosphate, but only in soil receiving P. A corresponding increase in unidentified inositol phosphates, presumably representing lower-order esters, was also observed after ruzigrass in soil with P application. We deduce that the degradation of inositol phosphates under ruzigrass with P application is due to greater ruzigrass productivity in the more fertile treatment, increasing the release of root exudates that solubilize inositol phosphates and promote their decomposition by phytase. We conclude that ruzigrass cover cropping can promote the cycling of recalcitrant soil organic P, but only when fertility is raised to a sufficient level to ensure a productive crop.     

Local diversity of native arbuscular mycorrhizal symbionts differentially affects growth and nutrition of three crop plant species

Intact whole native AMF communities occurring across a 100-m-long field were used for the evaluation of plant performance, as determined by the actual fungal species colonizing host roots. The soil from distinct plots within a “hot spot” field was collected to set up 54 experimental units where three different plant species were grown, in order to test whether the whole native AMF communities were able to differentially affect plant growth, to assess the genetic identity of the AMF actually colonizing the tested plants and to analyse their community composition in the different hosts. Molecular analyses revealed that plant growth and nutrition of the crop plants were differentially affected by the diverse native arbuscular mycorrhizal communities colonizing the roots of the three plants, whose performance varied depending on the identity of plant hosts and fungal symbionts, more than on a rich and diversified AMF community. Such results, improving our understanding of AMF distribution at the local scale, represent a starting point allowing the selection, isolation and characterization of the most efficient AMF assemblages to be used as inoculants in sustainable food production systems.