Impact de la corticothérapie post natale sur le devenir respiratoire clinique et fonctionnel à 7 ans des prématurissimes (résultats issus de la cohorte EPIPAGE Nord Pas-de-Calais 1997)

LILLE2-BU Santé-Recherche (593502101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

A convergent asymmetric synthesis of gamma-butenolides

Addition of aldehydes to the new enantiomerically pure lithiated sulfoxide 4 yielded gamma-butenolides of high enantiomeric purities after elimination of phenylsulfinic acid. The reaction with ketones was less stereoselective. (C) 1999 Published by Elsevier Science Ltd. All rights reserved

Effect of NaCl on proline and glycinebetaine metabolism in Kosteletzkya pentacarpos exposed to Cd and Zn toxicities

Background and aims Proline and glycinebetaine are osmolytes playing a role in resistance to salt and water stress but their involvement in plant adaptation to heavy metals remain unclear. Methods Young plants of the halophyte Kosteletzkya pentacarpos were grown in nutrient solution in the presence of Cd (20 or 40 μM) or Zn (200 or 400 μM), or a combination of both heavy metals and in the presence or absence of NaCl 50 mM for 48 h. Osmolytes concentrations, enzyme activities involved in their metabolism and expression of corresponding genes were determined in roots and leaves. Results Cadmium but not zinc increased proline and glycinebetaine in the leaves. Salinity reduced proline content in Cd-treated plants but increased it in plants exposed to Cd + Zn. Proline was produced through both glutamate and ornithine pathways while proline dehydrogenase was inhibited in response to heavy metals. Correlation between enzyme activities and corresponding gene expression was significant in the leaves but not in the roots. Gene coding for proline transport (KvProT) was upregulated in response to heavy metals. Conclusion Low NaCl dose (50 mM) afford protection to heavy metal stress in K. pentacarpos and its effect on osmolyte synthesis depends on considered metal and plant organ

Identification of Alternaria spp. on wheat by pathogenicity assays and sequencing

The pathogenicity of Alternaria spp. isolated from wheat leaves collected in regions where alternaria leaf blight has been reported was compared with that of IMI reference isolates of A. triticina and A. alternata using two durum and two bread wheat genotypes. To identify isolates putatively corresponding to A. triticina, morphological and DNA sequence analyses based on ribosomal DNA from the internal transcribed spacer (ITS) region (ITS1, 5.8S rRNA gene, ITS2) and toxicity bioassays of culture filtrate were combined. Glasshouse inoculations provided reliable information to assess the pathogenicity of A. triticina isolates on wheat. Alternaria leaf blight symptoms were produced by the A. triticina isolates only on durum wheat cv. Bansi, while A. alternata, A. tenuissima and A. arborescens isolates were found to be nonpathogenic on the wheat cultivars tested. Alternaria triticina isolates were distinguished from other Alternaria species by Simmons and Roberts' sporulation pattern 6 and two to three conidia per sporulation unit associated with primary conidia bearing long (> 7 mu m) apical secondary conidiophores. Phylogenetic analysis also proved effective at discriminating wheat-pathogenic A. triticina from other nonpathogenic Alternaria species. Alternaria triticina isolates yielded longer ITS sequences than A. alternata, A. tenuissima and A. arborescens isolates, leading to clear-cut differences as visualized with agarose gel electrophoresis. Additionally, only culture filtrates of A. triticina isolates caused nonspecific necrotic lesions on leaves of 3-week-old wheat plants

Effect of potash deficiency on hot susceptibility to cochliobolus sativus causing spot blotch on wheat

Helminthosporium leaf blight is the most important disease of bread wheat in the Indo-Gangetic plains and is caused by Cochliobolus sativus and Pyrenophora tricirepentis. Late planting and unbalanced fertility increase disease severity. A study on two genotypes BL2217(moderately resistant) and Ciano 79 (susceptible) was conducted in a greenhouse under controlled-environment with 3 levels of potassium fertilisation. Treatments consisted of half-strength standard Hoagland solution pH7.0 as control , and two levels of potassium deficient solutions containing only 36.8% and 13.5% potassium of the standard half-strength solution. Plants were inoculated with a C. sativus virulent isolate from Nepal. Disease severity (% DLA) and chlorophyll content measured as SPAD value (SPAD-502, Minolta Co. Ltd., Japan) at 3,7,10,14,17 and 21 days after inoculation were evaluated in inoculated and control plants, respectively. To assess the interaction of the pathogen with host cells, microscopic analysis and histochemical assays for H2O2 detection were performed 24-h and 48-h after inoculation. Potassium deficiency significantly increased disease severity in both genotypes. A significant(P<0.01) negative linear correlation between AUDPC and chlorophyll content was observed for both genotypes. Microscopic analysis and histochemical assay for H2O2 detection showed that cell wall apposition formation and hypersensitive reaction were significantly reduced in BL 2217 under potassium deficiency , stressing the importance of the soil fertility as part of an integrated crop management of HLB

Effect of growth stage on host sensitivity to helminthosporol toxin and susceptibility to Cochliobolus sativus causing spot blotch on wheat

Five wheat genotypes with differing field resistance to Cochliobolus sativus were tested in greenhouse conditions for their reaction to 1.0 mM helminthosporol (HL) toxin and for their resistance to the pathogen at the 4-leaf seedling, booting, anthesis completed and late milk grain stages. HL caused distinctly necrotic and chlorotic lesions only on the adult plants of highly susceptible genotypes Ciano T-79 and Sonalika. The level of toxin sensitivity and disease severity increased with adult plant growth stage, suggesting that susceptibility is related to plant physiology. However, genotype BL 1473 was found to be susceptible to the fungus but insensitive to the toxin, indicating the limitations of using the toxin as a screening too] for resistance. The results confirm earlier studies which showed a lack of correlation between resistance at the seedling stage and field observations. This underlines the importance of field screening for improving resistance to spot blotch in wheat. (c) 2006 Elsevier Ltd. All rights reserved

Mating types of Phaeosphaeria nodorum (anamorph Stagonospora nodorum) from Central Asia

The distribution was examined of the mating type idiomorphs (MAT-1 and -2) of Phaeosphaeria (anamorph Stagonospora) nodorum using DNA from 49 isolates collected from commercial and experimental fields in 2003 and 2004 in Central Asia. MAT-1 and -2 isolates were present in the Kazakh and Russian origins of P. nodorum, but no MAT-2 isolates were found in Tajikistan. The possibility of a skewed Tajik population cannot be excluded, considering that the sampled region in Tajikistan was geographically isolated from Kazakhstan and Russia

Genetic Diversity of the Mating Type and Toxin Production Genes in Pyrenophora tritici-repentis

Pyrenophora tritici-repentis, the causal agent of tan spot on wheat, is a homothallic loculoascomycete with a complex race structure. The objectives of this study were to confirm the homothallic nature of the pathogen, characterize mating type diversity and toxin production genes in a global collection of strains, and analyze how these traits are associated between each other and with existing races. The pseudothecia production capacity, race identification, mating type locus (MAT), internal transcribed spacer, and glyceraldehyde-3-phosphate dehydrogenase regions were analyzed in a selection of 88 strains originating from Europe, North and South America, North Africa, and Central and South Asia. Some (60%) strains produced pseudothecia containing ascospores, independent of their origin. Race identification obtained using the multiplex polymerase chain reaction targeting host-selective toxin (HST) genes was consistent, overall, with the results based on the inoculation of a set of differential wheat cultivars and confirmed the predominance of race 1/2 strains (approximate to 83%). However, discrepancies in race identification, differences from the reference tester strains, and atypical ToxA profiles suggest the presence of new races and HSTs. The MAT1-1 and MAT1-2 coding regions are consecutively arranged in a single individual, suggesting putative heterothallic origin of P tritici-repentis. Upstream from the MAT is an open reading frame of unknown function (ORFI) containing a MAT-specific degenerate carboxy-terminus. The phylogenetic analysis of the MAT locus reveals two distinct groups, unlinked to geographical origin or ToxA profile. Group I, the best-represented group, is associated with typical tan spot lesions caused by races 1, 2, 3, and 5 on wheat. It is more homogenous than group II encompassing race 4 strains, as well as isolates associated primarily with small spot lesions on wheat leaves or other hosts. Group II could contain several distinct taxa

Base catalysis in the Willgerodt-Kindler reaction

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

NaCl impact on Kosteletzkya pentacarpos seedlings simultaneously exposed to cadmium and zinc toxicities

Data regarding NaCl impact on halophyte plant species exposed to a polymetallic contamination remain scarce. Seedlings of the salt marsh species Kosteletzkya pentacarpos were simultaneously exposed to cadmium (10 μM) and zinc (100 μM) in the absence or presence of 50 mM NaCl. Heavy metal exposure reduced plant growth and increased Cd and Zn concentrations in all organs. Cd and Zn accumulation reduced net photosynthesis in relation to stomatal closure, decreased in chlorophyll concentration and alteration in chlorophyll fluorescence-related parameters. Salinity reduced Cd and Zn bioaccumulation and translocation, with a higher impact on Cd than Zn. It mitigated the deleterious impact of heavy metals on photosynthetic parameters. NaCl reduced the heavy metal-induced oxidative stress assessed by malondialdehyde, carbonyl, and H2O2 concentration. Subcellular distribution revealed that Cd mainly accumulated in the cell walls, but NaCl increased it in the cytosol fraction in the leaf and in the metal-rich granule fraction in the roots. It had no impact on Zn subcellular distribution. The additional NaCl contributed to a higher sequestration of Cd on phytochelatins and stimulated glutathione synthesis. The positive impact of NaCl on K. pentacarpos response to polymetallic pollution made this species a promising candidate for revegetation of heavy metal-contaminated salt areas. © 2018 Springer-Verlag GmbH Germany, part of Springer Natur