IgE-Mediated Cross-Reactivity among Leguminous Seed Proteins in Peanut Allergic Children

The immunological cross-reactivity among major protein- and oil-crops, including lupin, lentil, pea, peanut, kidney bean and soybean, has been studied by a combination of in vitro and in vivo experimental approaches: SDS-PAGE separations of legume protein extracts and immuno-blot revelations with 12 peanut-sensitive subjects’ sera, Immuno-CAP and Skin Prick tests on the same subjects. The immuno-blotting data showed a wide range of IgE-binding responses both displayed by one subject towards different plant extracts and among subjects. Differences were both quantitative and qualitative. The prevalent responses of most subjects’ sera were seen with peanut polypeptides, as expected, as well as with various polypeptides of the other legumes, the most recurrent of which were the basic subunits of the 11S globulins. The distribution of in vivo responses generally paralleled those obtained by in vitro approaches with strong responses elicited by peanut, lentil and pea protein extracts, especially by most sensitive subjects, thus providing a consistent overall set of results. In this work, the comparison of various approaches has allowed us to get an overall broad picture of the immunological cross-reactivities among proteins of widely used different seed species and to hypothesize the role of most conserved specific polypeptides.     

Insecticidal activity of scorpion toxin (ButaIT) and snowdrop lectin (GNA) containing fusion proteins towards pest species of different orders

BACKGROUND: The toxicity of a fusion protein, ButalT/GNA, comprising a venom toxin (ButaIT) derived from the red scorpion, Mesobuthus tamulus (F.), and Galanthus nivalis agglutinin (GNA), was evaluated under laboratory conditions against several pest insects. Insecticidal activity was compared with SFI1/GNA, a fusion comprising a venom toxin (SFI1) derived from the European spider Segestria florentina (Rossi) and GNA, which has been previously demonstrated to be effective against lepidopteran and hemipteran pests, and to GNA itself. RESULTS: Injection assays demonstrated that both fusion proteins were toxic to lepidopteran larvae, dipteran adults, coleopteran adults and larvae and dictyopteran nymphs. ButalT/GNA was more toxic than SFI1/GNA in all cases. GNA itself made a minor contribution to toxicity. Oral toxicity of ButalT/GNA towards lepidopteran pests was confirmed against neonate Spodoptera littoralis (Boisd.), where incorporation at 2% dietary protein resulted in 50% mortality and > 85% reduction in growth compared with controls. ButaIT/GNA was orally toxic to Musca domestica L. adults, causing 75% mortality at 1 mg mL^?1 in aqueous diets and, at 2 mg g^?1 it was orally toxic to Tribolium castaneum (Herbst.), causing 60% mortality and a 90% reduction in growth. CONCLUSIONS: Toxicity of the ButaIT/GNA recombinant fusion protein towards a range of insect pests from different orders was demonstrated by injection bioassays. Feeding bioassays demonstrated the potential use of the ButaIT/GNA fusion protein as an orally active insecticide against lepidopteran, dipteran and coleopteran pests. These experiments provide further evidence that the development of fusion protein technology for the generation of new, biorational, anti‐insect molecules holds significant promise. © Crown Copyright 2009. Reproduced with permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.     

Inventory of related wild species of priority crops in Venezuela

A prerequisite in any conservation programme of Plant Genetic Resources is estimation of diversity. The inventory of wild and naturalized relatives of priority crops in Venezuela (CWR) is based on the main Catalogues of Flora in the country, selecting taxa closely related to crops, according to the concepts of “gene pool” and “taxonomic group”. We included 47 genera, 217 species and 228 taxa belonging to 28 plant families. Among them, those with higher richness are: Fabaceae, Solanaceae, Araceae, Lauraceae, Dioscoreaceae, Poaceae, Rosaceae and Myrtaceae. Genera with a higher number of species are Xanthosoma, Persea, Dioscorea, Prunus, Psidium, Phaseolus, Solanum, Vigna, Capsicum, Manihot, Theobroma, Ipomoea and Oryza. A total of 26 endemic species are found, which belong to genera Xanthosoma, Persea, Dioscorea, Prunus and Manihot. The primary gene pool of crops include native species from genera such as Manihot, Solanum (Section Petota), Lycopersicon, Ananas, Capsicum, Dioscorea, Xanthosoma, Phaseolus, Theobroma, Ipomoea, Gossypium, Arracacia and Psidium. Genera with native species weakly related to crops are Saccharum, Persea, Ipomoea, Prunus, Vigna, Solanum (Section Melongena) and Daucus. Crop genera without native species in Venezuela are Allium, Musa, Brassica, Spinacia, Helianthus, Pisum, Lactuca, Citrus, Elaeis, Beta, Glycine and Triticum. Only a few taxa have already been evaluated according to the IUCN criteria, and Venezuelan accessions of crop wild relatives in national and international genebanks are very scarce.     

Biochemical and immunochemical characterization of different varieties of amaranth (Amaranthus L. ssp.) as a safe ingredient for gluten-free products

Celiac disease is a food intolerance triggered by the ingestion of gluten-containing cereals; the only therapy is a strict gluten-free diet for life. In recent years, amaranth flour has received considerable attention as an interesting source for the formulation of gluten-free products due to its high nutritional value and low content of prolamins, the toxic proteins for celiacs. The aim of this study was to characterize 40 amaranth varieties using both SDS-PAGE/immunoblotting and ELISA to assess their possible tolerance by celiac subjects. All of the amaranth samples studied showed similar binding affinities for both specific anti-gliadin antibodies and human IgAs. In most amaranth grains, the content of gluten-like proteins measured by ELISA was <20 ppm. The molecular characterization of amaranth proteins suggests that amaranth is safe for celiacs to consume. It is recommended that the most suitable amaranth varieties are those having the lowest content of proteins cross-reacting with anti-gliadin antibodies.     

Effect of Milling and Parboiling Processes on Arsenic Species Distribution in Rice Grains

This study identified the role of milling and parboiling on arsenic (As) content and its species in large numbers of rice samples. Total As contents were 108 ± 33 μg/kg in polished rice grains (PR), 159 ± 46 μg/kg in unpolished rice grains (UR), 145 ± 42 μg/kg in parboiled polished rice grains (PPR) and 145 ± 44 μg/kg in parboiled unpolished rice grains (PUR). The percentages of inorganic As (iAs) were 66% ± 8% in PR and from 72% to 77% in other grain categories. The polishing process reduced the As content in the rice grains, removing outer part of the UR with high amount of As, whereas the parboiling technique transferred the semimetal content within the grain. Total As and iAs contents were not significantly different in UR, PPR and PUR, homogenizing its distribution inside the grains. The results allowed to understand how different operations affect As fate and its chemical forms in grains.     

Modification of Secondary Metabolism and Flavonoid Biosynthesis Under Phosphate Deficiency in Bean Roots

The objective of this study was to evaluate the influence of phosphate deficiency on enzymatic activities and on compounds of the secondary metabolism linked with the production of root exudates in bean (Phaseolus vulgaris L.) plants cv. ‘Bianco di Bagnasco.’ Phosphate deficiency induced a decrease in root total soluble phenolic content, but also caused an increase in total soluble phenolic content of exudates. Alteration of phenolic production was paralleled by increased activity of L-phenylalanine ammonia-lyase (PAL) and decreased activity of chalcone isomerase (CHI) in roots. Two isoflavonoids daidzein and naringenin, have been detected in roots; they are considered signal molecules in the chemical trafficking with soil microorganisms. Naringenin content was reduced by phosphorus (P) deficiency, due to lower activity of CHI, the enzyme responsible for its biosynthesis. On the other hand, daidzein content was higher in –P plants than in the control. The results are discussed, considering the possible roles of phenolics and flavonoids in plant-soil microbe interactions and rizosphere modification.