Selective trafficking of non-cell-autonomous proteins mediated by NtNCAPP1

In plants, cell-to-cell communication is mediated by plasmodesmata and involves the trafficking of non-cell-autonomous proteins (NCAPs). A component in this pathway, Nicotiana tabacum NON-CELL-AUTONOMOUS PATHWAY PROTEIN1 (NtNCAPP1), was affinity purified and cloned. Protein overlay assays and in vivo studies showed that NtNCAPP1 is located on the endoplasmic reticulum at the cell periphery and displays specificity in its interaction with NCAPs. Deletion of the NtNCAPP1 amino-terminal transmembrane domain produced a dominant-negative mutant that blocked the trafficking of specific NCAPs. Transgenic tobacco plants expressing this mutant form of NtNCAPP1 and plants in which the NtNCAPP1 gene was silenced were compromised in their ability to regulate leaf and floral development. These results support a model in which NCAP delivery to plasmodesmata is both selective and regulated.     

Enzymatic and fungal treatments on sugarcane bagasse for the production of mechanical pulps

Crude ligninolytic enzyme extracts from Phanerochaete chrysosporium fungi were applied to sugarcane bagasse, prior to thermomechanical (TMP) and chemithermomechanical pulping (CTMP), and their properties were compared with the normal TMP and CTMP and also with TMP and CTMP pretreated with Ceriporiopsis subvermispora and P. chrysosporium fungi. The sugarcane bagasse was impregnated with the crude enzyme extract containing lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase (Lac). The results show that pretreatment with enzyme crude extract is an advantageous way to produce TMP and CTMP from sugarcane bagasse, as compared with only fungal pretreatment. Enzymatic pretreatments need only hours to enhance pulping and paper properties, compared with the weeks necessary for fungal treatments. Higher pulp yields were obtained compared with the fungal pretreatments. Enzymatic pretreatment reduced the energy consumption in a proportion similar to that of C. subvermispora fungal pretreatment and increased the pulp tensile index compared with the normal TMP and CTMP pulps, although the tensile strength was somewhat lower than that for pulps from C. subvermispora fungal pretreatment before CTMP processing. An advantage of enzymatic pretreatment is that brightness is increased compared with normal TMP and CTMP processes, whereas fungal pretreatments reduce the brightness.     

Arsenosugars in raw and cooked edible seaweed: characterization and bioaccessibility

The aim of this study was to examine arsenic species contents in raw and cooked edible seaweed and the bioaccessibility (maximum soluble concentration in gastrointestinal medium) of arsenosugars (glycerol ribose, phosphate ribose, sulfonate ribose, and sulfate ribose). For the analysis, a new chromatographic separation was developed in anion exchange, coupled with thermooxidation-hydride generation-atomic fluorescence spectrometry. An in vitro digestion (pepsin, pH 2; pancreatin-bile extract, pH 7) was applied to estimate arsenosugar bioaccessibility. Cooking of Undaria pinnatifida and Porphyra sp. did not alter the arsenic species present in the methanol-water extract, but it produced a substantial increase (2 and 5 times) in the As(V) extracted from Hizikia fusiforme. In all of the seaweeds analyzed, arsenosugar bioaccessibility was high (>80%) and did not vary as a result of cooking. Arsenosugar degradation as a result of in vitro digestion was not observed.     

Fish larvae distribution off Mejillones Peninsula (northern Chile) during a coastal upwelling event in Spring 1999: interactions with the cold upwelling plume

We examined the interaction between vertical and horizontal distribution of fish larvae off Mejillones Peninsula (23°S), northern Chile, under conditions of active coastal upwelling. An oceanographic survey covered spatial variability in temperature, chlorophyll- a (chl a ), dissolved oxygen, salinity and water density. Fish larvae were sampled during daytime and nighttime periods through two consecutive days in four stations: two inside and two outside of a well-developed upwelling plume, and at three depth strata: 0–20, 20–80 and 80–200 m. Eighteen taxa were analysed, of which the Myctophidae Diogenychthys atlanticus , Diogenichthys laternatus , and the anchovy Engraulis ringens , were most abundant. Our data showed little evidence for diel vertical migration and larvae were more abundant at depth (>80 m) under low temperature (∼12°C) and low chl a (∼2 mg m^–3), below the highly advective upper layer. The exploratory K -means analysis allowed the separation of data into two distinct habitats: upwelling and nonupwelling types. Most taxa were allocated in nonupwelling waters, i.e. outside the cold plume. However, short-term variations (<24 h) in the position of the upwelling plume influenced both horizontal and vertical occurrence as well as abundance of taxa, and caused variability in temperature, oxygen and chl a . These changes in oceanographic conditions, caused by upwelling circulation and the dynamics of the cold plume, may sharply modify the habitat of fish larvae and have an important role in survivorship and recruitment success.     

Physical,Compositional, and Wet‐Milling Characteristics of Mexican Blue Maize (Zea mays L.) Landrace

Mexico has the largest diversity of genetic resources for maize in the world, with about 59 different landraces. However, little is known about their wet‐milling characteristics. The aim of this study was to determine whether 15 Mexican blue maize (Zea mays L.) genotypes of Elotero de Sinaloa landrace collected in the northwestern region of Mexico have suitable wet‐milling properties. Great variability of physical, compositional, and wet‐milling characteristics among these blue maize genotypes was observed. The FAUAS‐457 and FAUAS‐488 maize genotypes had similar starch yield and starch recovery as reported for the wet‐milling industry, which indicated that they may be useful as a source of extractable starch. Residual protein levels in the starch fractions were in the range of 0.39–0.68%, and total solids recovery exhibited a mean value of 98.8%, indicating acceptable efficacy of the wet‐milling process. This process afforded starches from blue maize genotypes with low protein contents. Wet‐milling fractions correlated with the physical and chemical properties of the kernels. Our results indicate that Mexican blue maize genotypes contain characteristics that make them appropriate and utilizable at the industrial level, and they can also be valuable for improving wet‐milling characteristics of maize through breeding programs.     

Phylogenetic and morphological identification of Colletotrichum boninense: a novel causal agent of anthracnose in avocado

In recent years, anthracnose has become a significant disease affecting avocado fruit in the state of Michoacan, Mexico, where it significantly reduces fruit quality and commercial yield. Anthracnose has been assumed to involve Colletotrichum gloeosporioides and C. acutatum as causal agents. However, because of the increasing incidence of anthracnose, a more precise identification of the Colletotrichum spp. involved in this disease has become desirable. During the years 2004–2007, avocado fruits of different sizes exhibiting brown‐black and reddish spots on the pericarp and soft rot in the mesocarp, were gathered from orchards in nine counties. Fungal isolates were cultured on potato dextrose agar, and among these, 31 were selected for molecular, morphological and pathogenicity analyses. The molecular approaches used sequence typing of the internal transcribed spacer region and the partial nuclear large ribosomal subunit, allowing the unequivocal identification of C. gloeosporioides (71%), C. acutatum (16%) and C. boninense (13%). This last species has not been previously reported as being associated with anthracnose symptoms in avocado fruits anywhere in the world. Various morphological characteristics such as the size and shape of conidia were determined, as well as the conidial mass colour. Pathogenicity tests performed with all three species were conducted by inoculating healthy fruits. In each case, identical symptoms developed within 3 days of inoculation. Knowledge of the Colletotrichum populations in the Michoacan state, including the newly encountered avocado pathogen C. boninense, will facilitate further studies addressing the relationships between these Colletotrichum spp. and their avocado host.     

Prevalence of Leishmania spp. infection in domestic dogs in Chapare, Bolivia

Data on Leishmania spp. infection in dogs in Bolivia is scarce. Dogs from an area where 90% of human cutaneous leishmaniasis (CL) cases are due to Leishmania (Viannia) braziliensis were screened for Leishmania infection using established enzyme-linked immunosorbent antibody test (ELISA) protocols. Although none of the 51 dogs surveyed had clinical lesions indicative of CL, 6 out of 51 (11.8%) sampled dogs tested positive by ELISA.     

Effect of simulated gastrointestinal digestion on sialic acid and gangliosides present in human milk and infant formulas

The effects of simulated gastrointestinal digestion upon sialic acid and gangliosides in infant and follow-on formulas and human milk, as well as their bioaccessibility, have been evaluated. The gastric stage is the step that causes a greater decrease in sialic acid and ganglioside contents. The intestinal stage only decreases the total and individual contents of gangliosides. After gastrointestinal digestion, neither sialic acid nor gangliosides were found in the nonbioaccessible fraction. The highest bioaccessibility (100 × content in soluble fraction after gastrointestinal digestion/total content) of sialic acid is found in human milk (87%), followed by infant formula (77%) and follow-on formula (16%). In the case of gangliosides, the highest bioaccessibility is present in the follow-on formula (51%), followed by human milk (29%) and infant formula (5%).     

Stability of plant sterols in ingredients used in functional foods

The content of plant sterol (PS) and their oxidation products (POPs) in eight ingredients used to enrich functional foods was studied. A gas chromatographic (GC) technique with mass-spectrometric detection was used for identification, while GC with a flame ionization detector (GC-FID) was used for quantification. β-Sitosterol was the most abundant phytosterol, and the main POPs found were derived from this compound (7α/β-hydroxysitosterol, 7-ketositosterol, and sitostanetriol). The total amount of POPs found in the ingredients ranged from 29.03 to 110.02 μg/100 g PS. The β-sitosterol oxidation rates ranged from 10 to 50 μg β-sitosterol oxides/100 g of β-sitosterol. In view of this low rate of oxidation in the ingredients tested, it can be concluded that the PS remain stable in these ingredients. Significant correlations (p < 0.01) were found between total oxysitosterols versus β-sitosterol contents (R(2) = 86.5%) and between total POPs and total PS (R(2) = 81.6%).