Trait to gene analysis reveals that allelic variation in three genes determines seed vigour

Predictable seedling establishment is essential for resource-efficient and cost-effective crop production; it is widely accepted as a critically important trait determining yield and profitability. Seed vigour is essential to this, but its genetic basis is not understood. We used natural variation and fine mapping in the crop Brassica oleracea to show that allelic variation at three loci influence the key vigour trait of rapid germination. Functional analysis in both B. oleracea and the model Arabidopsis identified and demonstrated activity of genes at these loci. Two candidate genes were identified at the principal Speed of Germination QTL (SOG1) in B. oleracea. One gene BoLCVIG2 is a homologue of the alternative-splicing regulator (AtPTB1). The other gene BoLCVIG1 was unknown, but different alleles had different splice forms that were coincident with altered abscisic acid (ABA) sensitivity. We identified a further QTL, Reduced ABscisic Acid 1 (RABA1) that influenced ABA content and provide evidence that this results from the activity of a homologue of the ABA catabolic gene AtCYP707A2 at this locus. Lines containing beneficial alleles of these three genes had greater seed vigour. We propose a mechanism in which both seed ABA content and sensitivity to it determines speed of germination

Plasma neuropeptide Y concentrations in patients with neuroendocrine tumors

In order to develop an immunoradiometric assay for human neuropeptide (hNPY), a recently discovered and potent vasoconstrictor 36-amino-acid peptide, we used hNPY and some of its subpeptides to prepare monoclonal anti-NPY antibodies. Two monoclonal antibodies with high affinity for hNPY, that is affinity constants in the range of 10(10) mol/L-1, which respectively, reacted with the 9-18 portion and the 32-36 portion of hNPY were used in the immunoradiometric system. The assay was highly specific, NPY-related peptides such as pancreatic polypeptide and peptide YY not being detected. The lower limit of sensitivity was 0.5 pmol/L. In 303 normal subjects, plasma NPY concentrations were less than 0.5 pmol/L in 67%, 0.5 to 5.0 pmol/L in 25% and 5.1 to 30 pmol/L in the remaining 8%. A value of 7.5 pmol/L (95th percentile value in the normal group) was considered as the upper limit of normal. Among 111 patients with various neuroendocrine tumors, elevated plasma NPY concentrations were found in patients with pheochromocytomas and neuroblastomas, the highest plasma levels being found in patients with malignant pheochromocytomas. We conclude that patients with neuroendocrine tumors, especially secreting and or malignant tumors of the sympathochromaffin system, often have elevated plasma NPY concentrations

Effet du procédé de friture sur la répartition et l'état de l'eau mesurée par la RMN et IRM

The effects on frying on the water distribution and the starch granules of potatoes were studied using Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI). Potatoes slices, 5 cm diameter by 1.2 cm thickness were fried for 1, 3, 6 and 9 minutes at 170° C. The NMR relaxation results allowed to monitor the structural changes after frying. Into the sample core, the starch gelatinased and included changes on the water states and distribution. At the surface, the starch crystalline structure was confirmed and the water amount decrease and oil penetration were observed. The high sample heterogeneity induced by frying was confirmed by MRI measurements.Les effets du procédé de friture sur la répartition tissulaire de l'eau et dur les granules d'amidon sont étudiés par Résonance Magnétique Nucléaire (RMN) et Imagerie de Résonance Magnétique (IRM). Des tranches de pomme de terre de 5 cm de diamètre et 1,2 cm d'épaisseur sont frites pendant 1, 3, 6 et 9 minutes à 170° C. Les relaxations RMN permettent de caractériser les changements structuraux. A coeur, l'amidon gélatinise et modifie la relaxation des molécules d'eau et leur répartition. A la surface, la structure cristalline est confirmée, la teneur en eau diminue, tandis que la teneur en huile augmente. La forte hétérogénéité induite par le traitement est validée par les images IRM

Modeling the gelatinization-melting transition of the starch-water system in pulses (lentil, bean and chickpea)

International audienceCooking-induced conversion of starch, the major carbohydrate in pulses, is crucial for the digestibility of the seed. The gelatinization-melting transition of lentil, bean and chickpea starches was studied using Differential Scanning Calorimetry at different temperatures (T values ranged from 20 to 160 ◦C) and water contents (X from 0.2 to 3 kg kg 1 db). Gelatinization and melting endotherms were successfully modeled as two desummed Gaussian functions. This modeling enabled to generate the degree of starch conversion for any T and X conditions, a valuable indicator that could be used in predictive cooking models. As previously reported for melting, the temperature of gelatinization was found to depend on moisture in a way that can be modeledusing the FloryHuggins equation. The results suggest that starch undergoes melting transition irrespective of water content. The similar starch conversion diagram for the three pulses suggest that starches have similar thermal behavior

Faisabilité du refroidissement rapide de sardines à bord des chalutiers

National audienceThis article summarizes the research project achieved by Cemagref, CIRAD and CTCPA and dealing with cooling of fish. In this paper, only the thermal behaviour of sardine is described : immersion and showering cooling processes allowed a fast and efficient cooling of fish. Cooling durations have been reduced by a 4 factor compared with the well-known icing technique. It also shows up that showering cooling process could be implemented aboard small trawlers.Cet article fait la synthèse du projet de recherche mené conjointement par le Cemagref, le CIRAD et le CTCPA sur la réfrigération des poissons. Seul l'aspect comportement thermique lors du refroidissement de sardines est traité : il apparaît que les procédés de refroidissement par aspersion et immersion permettent un refroidissement rapide du poisson. Les durées de refroidissement sont réduites d'un facteur 4 par rapport aux techniques classiques de glaçage. Ainsi, des durées de traitement aussi courtes autorisent le refroidissement en continu par aspersion, et les surfaces à mettre en oeuvre seraient compatibles avec l'espace réduit disponible à bord des petits chalutiers