Solubility,partitioning, and activity of copper‐contaminated soils in a semiarid region

We studied the fate of Cu in contaminated semiarid soils from two areas with different mining activities in central Chile. Several regression models were evaluated to use soil physicochemical characteristics to predict solubility, partitioning, and activity of Cu. Furthermore, we hypothesize that the type of Cu mining compound (smelter dust versus tailing sand) can be another important variable determining the bioavailability of Cu. In the studied neutral to alkaline soils, soil organic matter (SOM) enhanced Cu solubility most probably through the formation of organic complexes with dissolved organic C (DOC). As a consequence, Cu solubility and partitioning were better explained by DOC concentration than by SOM content. On the other hand, Cu activity was mainly related to soil pH and was not affected by DOC. Although we found differences between the two study areas, Cu solubility and partitioning might not be as dependent upon the origin of the Cu mining compound as upon other physiochemical characteristics that influence the concentration and characteristics of DOC. Total Cu, pH, and DOC would be the most important variables to consider on Cu solubility, however, data about the nature of SOM may certainly improve the prediction models. Thus, multiple binding site models between Cu and DOC should be studied to improve predictions of Cu solubility.     

Transgenic wheat plants: a powerful breeding source

Plant breeders are always interested in new genetic resources. In thepast, the sources have been limited to existing germplasm. Geneticengineering now provides the opportunity for almost unlimited strategies tocreate novel resources. As a first stage, the Applied Biotechnology Center(ABC) at CIMMYT developed a method for the mass production of fertiletransgenic wheat (Triticum aestivum L.) that yields plants ready fortransfer to soil in 13–14 weeks after the initiation of cultures, and, over thecourse of a year, an average production of 5–6 transgenic plants per day.CIMMYT elite cultivars are co-bombarded with marker gene and a gene ofinterest with co-transformation efficiencies around 25–30%. The reliabilityof this method opens the possibility for the routine introduction of novelgenes that may induce resistance to diseases and abiotic stresses, allow themodification of dough quality, and increase the levels of micronutrientssuch as iron, zinc, and vitamins. The first group of genes being evaluatedby the ABC are the pathogenesis related (PR) proteins, such as thethaumatin-like protein (TLP) from barley, chitinase, and 1–3-glucanase. Stable integration of the genes in the genome andinheritance in the progeny were determined by phenotypical analyses thatchallenged the plants against a wide range of pathogens. Using these genes,we have recovered more than 1200 independent events (confirmed byPCR and Southern blot analyses) that show responses to the pathogens thatrange from tolerance to hypersensitive reactions. The quantity andanti-fungal activity of the endogenous thaumatin-like proteins were analyzedin T₁ and T₂ progeny plants. Western blot analyses showeddifferent protein patterns of the wheat endogenous TLPs. Preliminary resultsindicated that some patterns increased the resistance of transgenic wheatplants to Alternaria triticina. This relationship is being furtherinvestigated.     

Effect of thermal treatments on the chemical and biological value of irradiated and non-irradiated cowpea bean (Vigna unguiculata L. Walp) flour

Chemical and nutritional characteristics of irradiated and nonirradiated cowpea bean at 0.2 kGy submitted to several thermal treatments were studied. The cowpea bean flours irradiated at 0.2 kGy were superior to those non-irradiated concerning digestibility and the flours submitted to microwave oven were superior to those cooked under low pressure, autoclaved or even raw from the nutritional point of view. As to the presence of anti-nutritional factors, the results showed that the variety of cowpea bean under research presented neither trypsin inhibitor nor haemagglutinin activity, however, regarding tannin, a 0.006% content was found and considered negligible.     

Immunological analysis of serum for buckwheat fed celiac patients

Buckwheat (Fagopyrum esculentum, Moench), a herbaceous plant of the Polygonaceae family, does not have any affinity for the Gramineae family. It is commercially rated as a cereal, which has led to some misunderstanding concerning its use in gluten induced enteropathy or celiac disease. The effect of buckwheat flour ingestion by celiac patients was evaluated through the indirect immunofluorescence technique. Samples of serum were collected 30 days after the flour ingestion. Cryostat performed cuts of wheat and buckwheat grains were accomplished in order to compare the reactivity of their proteins and serum of celiac and normal patients. The assay revealed that the buckwheat flour presents no toxicity for the celiac patient and no anti-protein antibodies formation in the grain was observed for serum dilutions of 1:2 up to 1:32 with 0.15 M NaCl solution in 0.01 M phosphate buffer, pH 7.2 throughout the 30 day assay period. The results of the immunological assays showed that the buckwheat flour does not present toxic prolamines to celiac disease patients.     

The novel pyridazine pyrazolecarboxamide insecticide dimpropyridaz inhibits chordotonal organ function upstream of TRPV channels

The cover image is based on the Research Article The novel pyridazine pyrazolecarboxamide insecticide dimpropyridaz inhibits chordotonal organ function upstream of TRPV channels by Christian Spalthoff et al., https://doi.org/10.1002/ps.7352