Activité Fongicide du N-cetyl N,N,N-triméthylammonium Contre Botrytis cinerea Pers.

Fungicidal activity of N-cetyl N,N,N-trimethyl ammonium chloride to Botrytis cinerea Pers. Grey mould of grapes caused by Botrytis cinerea is the most important phytopatho-logical problem in swiss vineyards, since the appearance of resistant strains to dicarboxi-mides. Research for new chemicals is necessary. One compound, a cationic surfactant, the N-cetyl N,N,N-trimethyl ammonium chloride (CTAC), is very active in vitro against Botrytis cinerea. This product disturbs lethally the plasma membrane of conidia.     

Recherches sur les microorganismes de type mycoplasme dans les cicadelles vectrices et dans les vegetaux atteints de jaunisses

Résumé La phyllodie du trèfle, le Stolbur C et le Stolbur SM ont été étudiés chez la cicadelle Euscelis plebejus, les plantes Trifolium repens, Cuscuta subinclusa, Datura stramonium et Solanum lycopersicum en microscopie électronique, sur coupes ultrafines et après purification des agents infectieux.Dans les différents hôtes infectés, on distingue des éléments de grande taille, de forme ovoïde, amiboïde ou allongée, des corpuscules très contrastés, isolés ou en chaînettes, de fins filaments et des élements dégénérescents.Chez les cicadelles, la dégénérescence de ces microorganismes est probablement due à une réaction immunologique qui expliquerait la perte régulière du pouvoir infectieux de ces vecteurs.Chez les plantes, cette dégénérescence peut en partie rendre compte des phénomènes de rétablissements définitifs ou temporaires que manifestent parfois certains végétaux atteints de ces maladies.

---

Summary The microorganisms causing the diseases Clover phyllody, Stolbur C and Stolbur SM were studied in the leafhopper Euscelis plebejus, and in the plants Trifolium repens, Cuscuta subinclusa, Datura stramonium and Solanum lycopersicum, by electron microscope examination of ultrathin sections and purified suspensions.In infected host plants and insects the following components were distinguished: large, ovoid, amoeboid or elongated bodies, well-contrasted isolated or chained microbodies, minute filaments, and degenerate elements. Some of these bodies resemble mycoplasma.In the leafhoppers it is possible that the degeneration of these mycoplasma-like microorganisms is due to an immunological reaction, which may explain why aged vectors do not transmit the diseases.In plants, the degeneration of the microorganisms was also observed. This loss may partly account for the occasional complete, or temporary, recovery of diseased plants.

     

Biotransformation of C13-norisoprenoids and monoterpenes by a cell suspension culture of cv. Gamay (Vitis vinifera)

A cell suspension culture of cv. Gamay was studied for its ability to metabolize two different C₁₃-norisoprenoidic volatiles, β-ionone and dehydrovomifoliol, together with monoterpenes, geraniol and linalool, biogenetically common pathways sharing compounds. β-Ionone was totally metabolized leading to fourteen norisoprenoidic volatiles oxygenated mainly at carbons 3 or 4 of the cyclohexane ring or reduced at side chain. The biotransformation of dehydrovomifoliol was at a lesser extent, giving rise to oxygenated and reduced derivatives. The norisoprenoidic metabolites were present both under free and glycosylated forms. Geraniol and linalool were also metabolized, leading to several free and glycosylated compounds. S. Mathieu, J. Wirth contributed equally to the work and should be considered joint first authors. A short part of this paper was published at the proceedings of the 10th Weurman Flavour Research Symposium, Flavour Research at the Dawn of the Twenty-first Century, J.-L.Le Quere, P.-X.Etievant, Editors; Lavoisier,2003/Intercept Ltd, 2003.     

Incorporation de phenylalanine,de glucose et d'acide cinnamique dans les flavonols de l'oignon

In Allium cepa bulb scales, incorporation of ¹⁴C-phenylalanine, cinnamic acid and glucose were studied in relation to flavonol synthesis. The best incorporation into flavonols is obtained with either cinnamic acid or phenylalanine. ¹⁴C-glucose gives a slow incorporation into flavonol aglycone; this is because there is a big pool of free glucose in the scales in which the precursor is diluted. Under certain conditions, free cinnamic acid is quickly incorporated in a complex which may be a glycoside. After short labelling experiments with phenylalanine or cinnamic acid, some free precursor can be found in the scales a few days later but it is not available for flavonol synthesis. In these conditions, flavonol analysis shows in some cases, no turnover and in others, a turnover of 10% per day due to catabolism.     

Oviposition preference and larval performance of Epiphyas postvittana (Lepidoptera: Tortricidae) on Botrytis cinerea (Helotiales: Sclerotiniaceae) infected berries of Vitis vinifera (Vitales: Vitaceae)

In this paper we tested the behavior of gravid Epiphyas postvittana in selecting the most‐appropriate site for oviposition thus benefitting offspring performance. Our hypothesis was built on Jaenike's preference–performance hypothesis (also referred to as the “mother‐knows‐the‐best” hypothesis). To test this, we used the interacting Epiphyas postvittana, its host Vitis vinifera, and the pathogenic microbe Botrytis cinerea system. Populations of E. postvittana and B. cinerea often exist concurrently on V. vinifera in Australasia and their interaction and mutual influence are currently being explored, although the suggestion presently is that the relationship between E. postvittana and B. cinerea is mutualistic. We tested the effect of volatiles from B. cinerea‐infected berries and uninfected (control) berries of V. vinifera on the oviposition behavior of E. postvittana. We also characterized the effects of B. cinerea infection on the berries of V. vinifera on the growth and development of E. postvittana. Contrary to the preference–performance hypothesis, oviposition choices made by gravid E. postvittana did not result in the best offspring survival, development, and performance. The preference for oviposition by E. postvittana was strongly influenced by the olfactory and tactile cues. She laid fewer eggs on B. cinerea‐infected berries compared to uninfected berries of V. vinifera. The larvae of E. postvittana showed no preference to uninfected berries of V. vinifera. The larvae fed on B. cinerea‐infected berries of V. vinifera showing greater survival rate, shorter time to pupation, greater pupal mass, and on becoming adults they laid more numbers of eggs than the larvae that were enabled to feed on uninfected berries. The larvae of E. postvittana transport the conidia of B. cinerea and transmit grey‐mould disease to uninfected berries of V. vinifera.     

Volatiles from Botrytis cinerea‐infected and healthy berries of Vitis vinifera influence the oviposition behaviour of Epiphyas postvittana

Interactions among plants, plant‐feeding insects, and plant – pathogenic fungi are partially mediated by volatile compounds. Herbivorous insects use sensory cues to choose host plants for feeding and/or oviposition that are likely to support survival and development of progeny. It is known that some fungus‐induced alterations in plants can modify plant volatiles, which are recognized by the olfactory receptors of the insect, either as an attractant or as a deterrent. We tested for the presence of behaviour‐modifying volatiles emanating from the berries of Vitis vinifera L. (Vitaceae) infected with Botrytis cinerea Pers. (Helotiales). We tested the olfactory behaviour of adults of Epiphyas postvittana Walker (Lepidoptera: Tortricidae) to these volatiles using two‐choice and wind‐tunnel experiments. We hypothesized that olfactory cues influence E. postvittana's oviposition behaviour. We found that volatiles emanating from B. cinerea‐infected berries did not significantly attract the gravid females of E. postvittana; consequently, they laid significantly fewer eggs on infected berries. Furthermore, significantly fewer females of E. postvittana were found attracted to infected berries in the wind tunnel assay. Ethanol and 3‐methyl‐1‐butanol were abundant in B. cinerea‐infected berries. Oviposition assays made with laboratory standards of ethanol and 3‐methyl‐1‐butanol confirmed their role in regulating the olfactory behaviour of E. postvittana site selection.     

Changes of defense proteins in the extracellular proteome of grapevine (Vitis vinifera cv. Gamay) cell cultures in response to elicitors

In plant cells, elicitors induce defense responses that resemble those triggered by pathogen attack, such as the synthesis of phytoalexins and pathogen-related proteins which accumulate in the extracellular space. In the search for the particular proteins involved in defense responses, we investigated the changes in the extracellular proteome of a grapevine (Vitis vinifera cv. Gamay) cell suspension in response to elicitation with methylated cyclodextrins (MBCD) and methyl jasmonate (MeJA). Twenty-five of the 39 spots differentially expressed in 2-D gels were identified and found to be encoded by 10 different genes: three secretory peroxidases, chitinase-III, β-1,3-glucanase, thaumatin-like, SGNH plant lipase-like, NtPR27-like, xyloglucan endotransglycosylase and subtilisin-like protease. Most of them belong to the pathogenesis-related type proteins. A new class III secretory basic peroxidase and chitinase III were strongly induced in cultures treated with MBCD alone or combined with MeJA, while cultures treated with MeJA alone displayed a general repression of most of the extracellular proteins. Some of the proteins induced in grapevine cell cultures by MBCD are induced in other species by activators of systemic acquired resistance (SAR), a form of plant immunity. Collectively, the results suggest that treatment with MBCD resembles the effect of SAR induction agents in cell cultures.     

Les levures dans les eaux de la Moselle

We have identified 95 yeast species, in the river Moselle. Trichosporon cutaneum is a very good indicator for pollution caused by men and disappears rapidly in the zone of recovery. In not polluted water, the white yeasts are absent or nearly so, and only red pigmented yeasts are present. Sporobolomyces odorus is always present in these fractions. From the source till the border (Thionville) an increasing percentage of red yeasts present in the water is an indicator for a recovery of the river after heavy pollution.

     

Indices de fréquentation humaine dans les grottes à ours au Paléolithique moyen final: L’exemple de la Caverna Generosa dans les Préalpes lombardes, Italie

Already known like a palaeontological site for the study of Ursus spelaeus, Caverna Generosa also records ephemeral traces of human visits during the late Middle Palaeolithic. The cave opens at an altitude of 1450 m on the steep southern slope of the Monte Generoso Massif between the Lugano and the Como lakes and forms a complex group of narrow galleries and inner chambers. Sedimentological and palaeontological data and radiocarbon dates place both the cave-bear and the human frequentations in the first part of the isotopic stage 3 with climatic conditions shifting from cool and dry to more temperate and wet. Environment progressively changed from scarcely arboreal to arboreal-brush with small open spaces. Few flakes and Levallois flakes have been recovered scattered in the sediment and affected in most cases by intense postdepositional alteration. These items testify incursions of mousterian groups equipped with end-products and radiolarite flakes struck from blocks provisioned at lower locations southwards. End-products, namely Levallois flakes, prove that lithic reduction sequences were spatiotemporally fractionated in the covered territory. Conversely, it cannot be excluded a priori that sublocal radiolarite has been chipped at the entrance of the cave or at the very close surroundings for extraction of rudimental tools for immediate use. It is worth to mention that the small chert slabs in the Moltrasio limestone which crop throughout the cave walls were totally ignored. Caverna Generosa can be viewed as a refugia-location used in function of more or less constrained factors strongly influenced by high-altitude and bioclimatic situations. This type of site might well be integrated within the seasonal movements of humans in the western Lombard Pre-Alps area.     

Linkage disequilibrium in cultivated grapevine, Vitis vinifera L

We present here the first study of linkage disequilibrium (LD) in cultivated grapevine, Vitis vinifera L. subsp. vinifera (sativa), an outcrossing highly heterozygous perennial species. Our goal was to characterize the amount and pattern of LD at the scale of a few centiMorgans (cM) between 38 microsatellite loci located on five linkage groups, in order to assess its origin and potential applications. We used a core collection of 141 cultivars representing the diversity of the cultivated compartment. LD was evaluated with both independence tests and multilocus r ² , both on raw genotypic and reconstructed haplotypic data. Significant genotypic LD was found only within linkage groups, extending up to 16.8 cM. It appeared not to be influenced by the weak structure of the sample and seemed to be mainly of haplotypic origin. Significant haplotypic LD was found over 30 cM. Both genotypic and haplotypic r ² values declined to around 0.1 within 5–10 cM, suggesting a rather narrow genetic base of the cultivated compartment and limited recombination since domestication events. These first results open up a few application opportunities for association mapping of QTLs and marker assisted selection. Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users.     

Implications de données récentes sur les Lingules actuelles dans les interprétations paléoécologiques

Some traditional concepts on lingulid paleoecology are reviewed and discussed in regard to new data on the ecology of Recent lingulid brachiopods. Fossilization in life-position occurs under several ecological conditions, e.g. dessication or emersion of the substratum, prolonged increase in salinity, perhaps very rapid sedimentation, extreme changes in temperature, and fossilization of flat-lying shells occurs under prolonged reduction in salinity, storms, natural death. Catastrophic environmental changes cause the fossilization of lingulids. Such events may affect one or more ecological features which may have a direct or indirect effect on the lingulid biology. At this time, the biotype does not correspond to the habitual one, and the survival and behavior of the lingulids depend on the severity of the environmental changes and on the tolerance of the animals to the latter.     

Genome‐wide identification and expression analysis reveal the potential function of ethylene responsive factor gene family in response to Botrytis cinerea infection and ovule development in grapes (Vitis vinifera L.)

• The prevention of Botrytis cinerea infection and the study of grape seedlessness are very important for grape industries. Finding correlated regulatory genes is an important approach towards understanding their molecular mechanisms.
• Ethylene responsive factor (ERF) gene family play critical roles in defence networks and the growth of plants. To date, no large‐scale study of the ERF proteins associated with pathogen defence and ovule development has been performed in grape (Vitis vinifera L.). In the present study, we identified 113 ERF genes (VvERF) and named them based on their chromosome locations. The ERF genes could be divided into 11 groups based on a multiple sequence alignment and a phylogenetic comparison with homologues from Arabidopsis thaliana. Synteny analysis and Ka/Ks ratio calculation suggested that segmental and tandem duplications contributed to the expansion of the ERF gene family. The evolutionary relationships between the VvERF genes were investigated by exon–intron structure characterisation, and an analysis of the cis‐acting regulatory elements in their promoters suggested potential regulation after stress or hormone treatments.
• Expression profiling after infection with the fungus, B. cinerea, indicated that ERF genes function in responses to pathogen attack. In addition, the expression levels of most ERF genes were much higher during ovule development in seedless grapes, suggesting a role in ovule abortion related to seedlessness.
• Taken together, these results indicate that VvERF proteins are involved in responses to Botrytis cinerea infection and in grape ovule development. This information may help guide strategies to improve grape production.

     

Influence de la 6-benzylaminopurine sur la différenciation plastidiale dans les cotylédons de concombre

Treatment with 6-benzylaminopurine (6-BAP; 10⁻⁵ g/ml) accelerates the growth of detached cucumber cotyledons (Cucumis sativas L.), primarily through an increased water uptake by the tissues. A comparative study of pigment composition and ultrastructure in 6-BAP treated and untreated cotyledons shows that cytokinin, in the presence of light, accelerates the transformation of etioplasts into chloroplasts. 6-BAP also enhances the synthesis of membrane precursors as indicated by the formation of a dense prolamellar body and by the persistence of a pseudo-cristalline structure in 6-BAP treated material. Stimulation of biosynthetic activity by cytokinin leads simultaneously to an increase in the rate of the pigment synthesis and to an acceleration in the building of the lamellar system. Furthermore, chloroplasts of 6-BAP treated cotyledons show abnormal features such as a striking increase in the number of thylacoids per granum and a poor development of the intergranal system.     

Sur les plantes vasculaires dans le devonien de Libye

Study of the vegetation in Libya during the Devonian period has been made in different works concerning macrofossils (psilophytes, rhyniophytes, trimerophytes and lycophytes of the Murzuk Basin) and microrests and spores of the Rhadamès Basin.A comparison between the spores found in the sediments and those of fossil plants already known in other areas of the world, during the Devonian allowed us to confirm the hypothesis suggested by the study of microrests. Thus, one may suppose that during the Devonian period in Libya, as well as the four groups mentioned above, there may also have lived some plants such as sphenophytes (?) (one spore genus), filicophytes (?) (stomates and spores of five species), progymnosperms (?) (tracheids and spores of two species) and paleophyllales (?) (spore of one species).