Dual role of the pigmentation gene B in affecting carotenoid and vitamin E content in squash (Cucurbita pepo) mesocarp

The yellow and orange colorations of the mesocarp of pumpkins and squash of Cucurbita pepo are due to the presence of carotenoid pigments that also greatly contribute to their nutritional value. Carotenoids, as well as tocopherols (vitamin E), are isoprenoid compounds formed by branches of a common biosynthetic pathway. Photodiode array HPLC analysis was used to simultaneously determine the content and composition of fruit-flesh carotenoids and tocopherols in five pairs of near-isogenic lines differing in the allelic state of genes previously identified as having profound effects on fruit color. The dominant B allele promoted carotenoid accumulation up to 5-fold and prevented tocopherol accumulation in all genetic backgrounds. The dominant L-2 allele doubled carotenoid content and, in combination with the dominant B allele, increased carotenoid content by 10-15-fold as compared to the recessive l-2 allele. The genes D and L-1 had no significant effects on mesocarp tocopherols or carotenoids content. These results indicate that the B gene, which affects both carotenoids and tocopherols, may play a regulatory role in the flux of the isoprenoid pathway products.     

Nonprotein amino acids of plants: significance in medicine,nutrition, and agriculture

Those nonprotein amino acids found in food and fodder plants and known to be toxic to man and domestic animals are described. These include toxins from many legume genera including Lathyrus, from other higher plant families, from seaweeds, and from fungi. Some inhibit protein synthesis, while others are incorporated into proteins with toxic effects. Basic processes such as urea synthesis and neurotransmission may be disrupted. The probable roles of nonprotein amino acids in protecting plants against predators, pathogens, and competing plant species are considered. The need to learn more of the nutritive value of nontoxic nonprotein amino acids and to explore the potential of others either as drugs or as leads to drugs in human and veterinary medicine is emphasized.     

Evaluation of magnetic iron oxides as sediment tracers in water erosion experiments

Water erosion is one of the major concerns with regard to sustainability of agricultural systems in Mediterranean countries (e.g. olive farming areas in Southern Spain). The limitations of the technologies traditionally used in erosion measurement has created increased interest in the use of innovative erosion tracers useful for monitoring erosion and determining deposition rates in the field. In this work, we evaluated the potential of magnetic iron oxide (Fe₃O₄) as a soil tracer. Particle size distribution of the magnetic iron oxide, mobility under drainage conditions and the effect of the aggregate size distribution in blank and tagged soils were studied. The use of magnetic iron oxide to estimate soil losses at small-scale was also examined using a portable rainfall simulator and measuring magnetic susceptibility before and after each simulated rainfall. The properties of the magnetic iron oxide, including a particle size distribution similar to that of soil aggregates, strong binding to soil particles, little mobility in soil, very high magnetic susceptibility relative to the typically low background values of the studied soils, innocuous to environment and low cost, make it an effective soil tracer for estimating soil losses at a small-scale.     

Water pollution by Pangasius production in the Mekong Delta,Vietnam: causes and options for control

In this paper, we analyse water pollution caused by farming and processing Pangasianodon hypophthalmus in the Mekong Delta of Vietnam. The results show that 1 tonne of frozen fillets releases 740 kg BOD, 1020 kg COD, 2050 kg TSS, 106 kg nitrogen and 27 kg phosphorus, of which wastewater from fish ponds contributes 60–90% and sludge from fish ponds and wastewater from processing facilities contributes 3–27% of the total emissions. Overall, the combined waste emissions from Pangasius production and processing account for <1% of the total TSS, nitrogen and phosphorus loads in the Mekong Delta. Despite the relatively low contribution to water pollution, further reductions are possible through more efficient use of inputs and low-cost treatment and re-use of effluent streams. The use of cleaner production technologies and the development of wastewater treatment plants could be applied to large farms and processing facilities to reduce water pollution in Pangasius processing. Low-cost options for small-scale farms include the optimization of the discharge design for the re-use of wastewater.     

Subcutaneous, but not intratracheal administration of the TLR9 agonist, CpG DNA transiently reduces parainfluenza-3 virus shedding in newborn lambs

Synthetic oligodeoxynucleotides (ODN) containing CpG motifs signal through TLR9 and activate innate immunity resulting in protection against a variety of parasitic, bacterial and viral pathogens in mouse models. However, few studies have demonstrated protection in humans and large animals. In the present investigations, we evaluated protection by CpG ODN in a parainfluenza-3 (PI-3) virus infection in neonatal lambs. Subcutaneous (SC) injection of CpG ODN induced high levels of 2′5′-A synthetase and significantly reduced PI-3 virus shedding in newborn lambs. Furthermore, pre-treatment of newborn lambs with SC CpG ODN 2 days, but not 6 days prior to the virus challenge was protective. In contrast, intratracheal (IT) administration of CpG ODN induced 2′5′-A synthetase but had no significant impact on PI-3 virus shedding in nasal secretions. We conclude that a systemic administration of CpG ODN and the timing of the treatment are critical for the protection of neonatal lambs against a respiratory viral infection.     

Sediment source fingerprinting: benchmarking recent outputs,remaining challenges and emerging themes

Journal of Soils and Sediments - This review of sediment source fingerprinting assesses the current state-of-the-art, remaining challenges and emerging themes. It combines inputs from international...     

Cultivar mixture effects on disease and yield remain despite diversity in wheat height and earliness

Cultivar mixtures can stabilize yield and reduce pathogen spread in plant populations. A field experiment was performed to determine (a) whether a large difference between the cultivars in the mixture (e.g., plant height or earliness) would have an impact on mixture performance, and (b) whether such differences would modify the classical rules for mixture design. Mixtures were constituted from wheat cultivars with diversity for many traits, including plant height, flowering date, disease resistance, and yield potential. The field experiment was conducted over 3 years, testing each year 72–90 mixtures of two, four, or eight cultivars, and their corresponding pure stands. Disease severity and yield of cultivar mixtures were strongly related to the mean values of the component cultivars in pure stands. Despite the considerable diversity of the mixtures tested, the classic rules (e.g., proportion of susceptible cultivars) already tested in mixtures with similar height and earliness were effective for decreasing disease severity. Agronomic heterogeneity for traits such as plant height, yield potential, or earliness of the cultivars in mixtures did not have a negative impact on disease severity and yield relative to pure stands. Increasing the number of cultivars in the mixture from two to eight had no impact on the mean disease severity and yield of the mixtures, but reduced the variability of disease severity and yield in the mixture relative to pure stands. These results suggest that it may be possible to increase within-field wheat diversity by combining more contrasting cultivars in mixtures than was previously thought.     

Air Classification of Pin‐Milled Soybean Hulls

Commercial soybean hulls (14.6% crude protein) were pin milled and then air classified into five fractions to determine whether the hull structure can be disrupted and the protein constituents concentrated. The number of pin millings had only a small effect on the weight distribution of the five fractions. After one grinding, the sum of fractions 1 and 2 (<15–18 μm) represented only 3% of total hulls, and on three grindings, they amounted to only 6% of the hulls. Fraction 3 (19–24 μm) shifted from 16 to 20% with three grindings, while fraction 4 (25–30 μm) remained unchanged at 5%. Fraction 5 (>30 μm) shifted from 75 to 69% on three pin millings to compensate for the shifts noted in fractions 1–3. Scanning electron microscopy revealed that fractions 1 and 2 consisted of the parenchymal cell layers (innermost portion) of the hulls; these fractions had three times the protein content and more than twice the amount of lipids found in the ground starting material. Fraction 3 contained many of the hourglass cells typically found in the middle layer of the hulls plus parenchyma cell material and exhibited about twice the amount of protein and lipid found in the starting hulls. Fraction 4 included large hourglass cells plus globular material and contained about twice the amount of protein and about one and one‐half times the lipid of the starting material. Fraction 5 consisted primarily of clumps of palisade cells (outer cellular layer) adhering to each other and had a lower protein and lipid content than the starting hulls. Thus, pin milling causes some selective disruption of the hulls where parenchyma cell layers and hourglass cells are partially released. The palisade cells, however, are the most difficult to disrupt and constitute the fraction most resistant to pin milling. Our findings suggest that pin milling soybean hulls in combination with air classification can be used to concentrate the proteins and lipids in the fines fractions.