118 research outputs found

    Synthetic tools for the characterization of galactofuranosyl transferases. Glycosylations via acylated glycosyl iodides

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    With the aim to develop synthetic tools for the characterization of galactofuranosyltransferases, the synthesis of 9-decenyl glycosides of D-Manp, D-Galf and beta-D-Galf-(1,3)-D-Manp was targeted. The interest in the alkenyl aglycone arises from its potential conjugation reactions, once the terminal double bond has been conveniently functionalized. The glycosylation of beta-D-Galf-(1,3)-D-Manp was attempted by two different approaches: the trichloroacetimidate method and the glycosylation via the glycosyl iodide. The conditions for the latter were established on the basis of glycosylation assays of per-Oacetylmannose.On the other hand, the study of glycosylation reactions via per-O-bezoylated galactofuranosyl iodide confirms the versatility of glycosyl iodides as donors.Fil: Baldoni, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono; Argentina;Fil: Marino, María Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono; Argentina

    Expedient synthesis of 1,6-anhydro-α-D-galactofuranose, a useful intermediate for glycobiological tools

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    A new and efficient three-step procedure for the synthesis of 1,6-anhydro-α-D-galactofuranose is described. The key step involves the formation of the galactofuranosyl iodide by treatment of per-O-TBS-D-Galf with TMSI, the selective 6-O-desilylation by an excess of TMSI, and the simultaneous nucleophilic attack of the 6-hydroxy group on the anomeric carbon, with the iodide as a good leaving group. This compound is a good precursor for building blocks for the construction of 1→6 linkages.Fil: Baldoni, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Marino, María Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono; Argentin

    Controlling for genetic identity of varieties, pollen contamination and stigma receptivity is essential to characterize the self-incompatibility system of Olea europaea L.

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    open7siBervillé et al. express concern about the existence of the diallelic self-incompatibility (DSI) system in Olea europaea, mainly because our model does not account for results from previous studies from their group that claimed to have documented asymmetry of the incompatibility response in reciprocal crosses. In this answer to their comment, we present original results based on reciprocal stigma tests that contradict conclusions from these studies. We show that, in our hands, not a single case of asymmetry was confirmed, endorsing that symmetry of incompatibility reactions seems to be the rule in Olive. We discuss three important aspects that were not taken into account in the studies cited in their comments and that can explain the discrepancy: (i) the vast uncertainty around the actual genetic identity of vernacular varieties, (ii) the risk of massive contamination associated with the pollination protocols that they used and (iii) the importance of checking for stigma receptivity in controlled crosses. These studies were thus poorly genetically controlled, and we stand by our original conclusion that Olive tree exhibits DSI.openSaumitou-Laprade, Pierre; Vernet, Philippe; Vekemans, Xavier; Castric, Vincent; Barcaccia, Gianni; Khadari, Bouchaib; Baldoni, LucianaSaumitou-Laprade, Pierre; Vernet, Philippe; Vekemans, Xavier; Castric, Vincent; Barcaccia, Gianni; Khadari, Bouchaib; Baldoni, Lucian

    Expedient synthesis of 1,6-anhydro-α-D-galactofuranose, a useful intermediate for glycobiological tools

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    Abstract A new and efficient three-step procedure for the synthesis of 1,6-anhydro-α-D-galactofuranose is described. The key step involves the formation of the galactofuranosyl iodide by treatment of per-O-TBS-D-Galf with TMSI, the selective 6-O-desilylation by an excess of TMSI, and the simultaneous nucleophilic attack of the 6-hydroxy group on the anomeric carbon, with the iodide as a good leaving group. This compound is a good precursor for building blocks for the construction of 1→6 linkages. 165

    Identification of new polymorphic regions and differentiation of cultivated olives (Olea europaea L.) through plastome sequence comparison

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    <p>Abstract</p> <p>Background</p> <p>The cultivated olive (<it>Olea europaea </it>L.) is the most agriculturally important species of the Oleaceae family. Although many studies have been performed on plastid polymorphisms to evaluate taxonomy, phylogeny and phylogeography of <it>Olea </it>subspecies, only few polymorphic regions discriminating among the agronomically and economically important olive cultivars have been identified. The objective of this study was to sequence the entire plastome of olive and analyze many potential polymorphic regions to develop new inter-cultivar genetic markers.</p> <p>Results</p> <p>The complete plastid genome of the olive cultivar Frantoio was determined by direct sequence analysis using universal and novel PCR primers designed to amplify all overlapping regions. The chloroplast genome of the olive has an organisation and gene order that is conserved among numerous Angiosperm species and do not contain any of the inversions, gene duplications, insertions, inverted repeat expansions and gene/intron losses that have been found in the chloroplast genomes of the genera <it>Jasminum </it>and <it>Menodora</it>, from the same family as <it>Olea</it>.</p> <p>The annotated sequence was used to evaluate the content of coding genes, the extent, and distribution of repeated and long dispersed sequences and the nucleotide composition pattern. These analyses provided essential information for structural, functional and comparative genomic studies in olive plastids. Furthermore, the alignment of the olive plastome sequence to those of other varieties and species identified 30 new organellar polymorphisms within the cultivated olive.</p> <p>Conclusions</p> <p>In addition to identifying mutations that may play a functional role in modifying the metabolism and adaptation of olive cultivars, the new chloroplast markers represent a valuable tool to assess the level of olive intercultivar plastome variation for use in population genetic analysis, phylogenesis, cultivar characterisation and DNA food tracking.</p

    Survey of over 4, 500 monumental olive trees preserved on-farm in the northeast Iberian Peninsula, their genotyping and characterization

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    Inventorying, characterising and conserving on-farm ancient olive trees is a priority for safeguarding their genetic, natural and agricultural value and for protecting ancient genotypes threatened with extinction. In the “Taula del Sénia” (M-TdS) area (northeast Iberian Peninsula) a highly important cultural landscape has been preserved, in which the olive groves play an outstanding social and economic role: the ancient olive trees, sustained by many local farmers, constitute a living heritage and provide a clear example of High Nature Value (HNV). A total of 4526 ancient productive olive trees, with a trunk circumference (PBH) larger than 3.5 m, were inventoried and their spatial localization and biometric measurements were collected. 41 olive trees have shown the highest category in monumentality (PBH >8.1 m). The outstanding trees might be 634–1082 years old. The endocarp morphology of a representative sample of the most ancient trees from this settlement resulted in 14 different profiles. The ancient trees genotyped, through eight simple sequence repeat (SSR) markers, revealed 43 SSR profiles. The use of SSR enabled us to verify that most of the trees (98%) belong to the local cv. ‘Farga’, a male sterile variety with a rare chlorotype, only a few trees corresponded with other local varieties, ‘Morrut’, ‘Canetera’ and ‘Sevillenca’, and ten hitherto unidentified genotypes were distinguished, some with chloroplast lineages different from the ‘Farga’ type. The M-TdS area holds a unique living and exploitable heritage with the highest concentration of ancient olive trees worldwide. On-farm conservation of this germplasm by the community of local growers is enabling preservation of this important source of genetic variation, potentially holding traits of resilience and adaptation to adverse soil and climatic conditions, demonstrated by the survival of these trees over the centuries. Farmers have undertaken initiatives to valorize the olive oil deriving from these M-TdS trees.info:eu-repo/semantics/acceptedVersio

    Bioactive compound profiling of olive fruit: the contribution of genotype

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    The health, therapeutic, and organoleptic characteristics of olive oil depend on functional bioactive compounds, such as phenols, tocopherols, squalene, and sterols. Genotype plays a key role in the diversity and concentration of secondary compounds peculiar to olive. In this study, the most important bioactive compounds of olive fruit were studied in numerous international olive cultivars during two consecutive seasons. A large variability was measured for each studied metabolite in all 61 olive cultivars. Total phenol content varied on a scale of 1–10 (3831–39,252 mg kg1) in the studied cultivars. Squalene values fluctuated over an even wider range (1–15), with values of 274 to 4351 mg kg1. Total sterols ranged from 119 to 969 mg kg1, and total tocopherols varied from 135 to 579 mg kg1 in fruit pulp. In the present study, the linkage among the most important quality traits highlighted the scarcity of cultivars with high content of at least three traits together. This work provided sound information on the fruit metabolite profile of a wide range of cultivars, which will facilitate the studies on the genomic regulation of plant metabolites and development of new olive genotypes through genomics-assisted breeding.EEA San JuanFil: Mousavi, Soraya. National Research Council. Institute of Biosciences and Bioresources; ItaliaFil: Stanzione, Vitale. National Research Council. Institute for Agricultural and Forest Systems of the Mediterranean; ItaliaFil: Mariotti, Roberto. National Research Council. Institute of Biosciences and Bioresources; ItaliaFil: Mastio, Valerio.Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Juan; Argentina.Fil: Mastio, Valerio. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Azariadis, Aristotelis. Mediterranean Agronomic Institute of Chania. Department of Horticultural Genetics and Biotechnology; GreciaFil: Passeri, Valentina. National Research Council. Institute for Agricultural and Forest Systems of the Mediterranean; ItaliaFil: Valeri, Maria Cristina. National Research Council. Institute of Biosciences and Bioresources; ItaliaFil: Baldoni, Luciana. National Research Council. Institute of Biosciences and Bioresources; ItaliaFil: Bufacchi, Marina. National Research Council. Institute for Agricultural and Forest Systems of the Mediterranean; Itali
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