Textural changes of heterozygous tomatoes in the alcobaca loci

Foram avaliadas as modificações ocorridas durante o amadurecimento de três pares de híbridos de tomates do grupo multilocular, quase isogênicos, à exceção do loco alcobaça. O experimento foi conduzido na Universidade Federal de Lavras, em delineamento em blocos casualizados. Os pares de híbridos (Stevens x Flora Dade e Stevens x TOM-559; Piedmont x Flora Dade e Piedmont x TOM-559; NC-8276 x Flora Dade e NC-8276 x TOM-559) foram avaliados em quatro estádios de amadurecimento (breaker, rosa, vermelho-claro e vermelho), em quatro repetições. Os híbridos cujo genitor comum foi Flora Dade corresponderam ao genótipo normal (+/+), enquanto os híbridos heterozigotos alcobaça (+/alc) foram provenientes do genitor comum TOM-559. A textura não foi afetada pelo alelo alcobaça nos estádios predeterminados de amadurecimento. Já a porcentagem de solubilização das substâncias pécticas, bem como a atividade das enzimas pectinametilesterase e poligalacturonase, foram influenciadas pelo alelo alcobaça, que determinou a sua contenção. O amadurecimento dos tomates (+/+) e (+/alc) foi marcado por intenso amaciamento, acompanhado por incremento na atividade da poligalacturonase e solubilização das substâncias pécticas.Textural changes occurred during ripening of three pairs of plurilocular tomato's hybrids, nearing isogenics, excepting the alcobaca loci, were studied. The trial was carried out in Universidade Federal de Lavras (UFLA), MG, Brazil, with a randomized complete block design. The pairs of hybrids (Stevens x Flora Dade e Stevens x TOM-559; Piedmont x Flora Dade e Piedmont x TOM-559; NC-8276 x Flora Dade e NC-8276 x TOM-559) were evaluated in four stages of ripening (breaker, pink, light-red and red), in four replications. Hybrids whose common genitor was Flora Dade corresponded to the normal genotype (+/+), whereas the alcobaca heterozygous hybrids (+/alc) were originated from the common genitor TOM-559. Texture was not affected by the alcobaca allele in the predetermined stages of ripening. On the other hand, the solubilization percentage of pectic substances as well as the activity of pectinmethilesterase and polygalacturonase were influenced by the alcobaca allele which determined its contention. Tomato ripening, (+/+) and (+/alc), was characterized by intense softening associated with an increase in polygalacturonase activity and solubilization of pectic substances

Les peuples Rom en France. Empreintes de leur langue dans la langue française.

Le présent projet vise à rapprocher les Roms en élaborant une image véritable du groupe. Ceci a été mené à terme grâce à la rédaction d’une approche historique brève des peuples Rom ainsi que d’une étude pour rendre compte de la portée de l’influence de la langue des Rom dans le français. Ces approximations constituent un moyen pour débarrasser ces minorités des clichés dont elles sont accompagnées. L’introduction du travail est construite à partir d’un état de la question et d’un point de désambiguïsation afin de clarifier les concepts qui seront développés dans les suivants points de l’étude. Ensuite, l’approche historique est présentée comme un survol de l’histoire des Rom et s’accompagne d’un point qui explique les différents sous-groupes qu’il existe en France et leur distribution. Finalement le travail aborde le sujet de l’influence de la langue des Rom dans le français actuel par le biais de l'analyse d'une enquête d'emprunts lexicaux qui peut être consultée dans les annexes du travail. À l'aide de ces outils, on a franchi une barrière car ce n'est qu'en étudiant les Rom de près qu'on a acquis une véritable connaissance au délà des aspects superficiels

TWO MODELS FOR THE COMPUTATION OF LAMINAR FLAMES IN DUST CLOUDS

International audienceWe address two models for the simulation of dust clouds premixed combustion: the first one consists in usual balance equations; to derive the second one, we suppose that the solution takes the form of a travelling combustion wave and track the location of the flame brush by a phase-field-like technique. We build a finite volume fractional step scheme for both models, which respects the natural physical bounds of the unknowns. Then we assess the consistency of both formulations

Molecular and biochemical characteristics of a gene encoding an alcohol acyl-transferase involved in the generation of aroma volatile esters during melon ripening.

Two genes (CM-AAT1 and CM-AAT2) with strong sequence homology (87% identity at the protein level) putatively involved in the formation of aroma volatile esters have been isolated from Charentais melon fruit.They belong to a large and highly divergent family of multifunctional plant acyl-transferases and show at most 21% identity to the only other fruit acyl-transferase characterized so far in strawberry.RT-PCR studies indicated that both genes were specifically expressed in fruit at increasing rates in the early and mid phases of ripening.Expression was severely reduced in ethylene-suppressed antisense ACC oxidase (AS) fruit and in wild-type (WT) fruit treated with the ethylene antagonist 1-MCP.Cloning of the two genes in yeast revealed that the CM-AAT1 protein exhibited alcohol acyl-transferase activity while no such activity could be detected for CM-AAT2 despite the strong homology between the two sequences.CM-AAT 1 was capable of producing esters from a wide range of combinations of alcohols and acyl-CoAs.The higher the carbon chain of aliphatic alcohols, the higher the activity.Branched alcohols were esterified at differential rates depending on the position of the methyl group and the nature of the acyl donor. Phenyl and benzoyl alcohols were also good substrates, but activity varied with the position and size of the aromatic residue.The cis/trans configuration influenced activity either positively (2-hexenol) or negatively (3-hexenol).Because ripening melons evolve the whole range of esters generated by the recombinant CM-AAT1 protein, we conclude that CM-AAT1 plays a major role in aroma volatiles formation in the melon

Down-regulation of DR12, an auxin-response-factor homolog, in the tomato results in a pleiotropic phenotype including dark green and blotchy ripening fruit.

Following differential screening of gene expression during tomato fruit development, we isolated developmentally regulated (DR) clones, including several putative transcription factors. Based on sequence homology, DR1, DR3, DR4 and DR8 are members of the Aux/IAA family, and DR12 belongs to the auxin response factor (ARF) family of transcription factors. Importantly, mRNA accumulation for the Aux/IAA-like genes was regulated by ethylene in tomato fruit but not in the leaves, indicating that these putative auxin response components also participate to the ethylene-dependent regulation of gene expression in a tissuespecific manner. The functional significance of DR12, the ARF-like gene, was investigated by cellular biology and reverse genetics approaches. Heterologous protein targeting studies, carried out using a DR12–GFP gene fusion construct, revealed specific nuclear localization of the DR12-encoded protein, in accordance with its putative function as a transcriptional regulator. Transgenic plants over- and under-expressing DR12 were generated in order to explore the physiological role of the gene. Both antisense and sense co-suppressed DR12-inhibited lines displayed a pleiotropic phenotype that included dark-green immature fruit, unusual cell division in the fruit pericarp, blotchy ripening, enhanced fruit firmness, upward curling leaves and increased hypocotyl and cotyledon growth. While a perturbation of the response to auxin may explain some of the phenotypes, surprisingly, the expression of members of four classes of early auxin-regulated genes was unaffected in the DR12-inhibited plants. The involvement of this ARF-like encoded protein in mediating the auxin response is discussed along with the possibility that it might affect responsiveness to other phytohormones in the tomato

An ethanol spray at veraison enhances colour in red wines

Aqueous ethanol (5% v/v) was sprayed onto bunches of Vitis vinifera L. cv. Cabernet Sauvignon 8–9 weeks following full flowering (controls were sprayed with water). Internal ethylene concentration in treated berries increased to a maximum within 6 hours, and berry colour subsequently increased substantially (maximum attained 2–3 weeks after spraying). Berry fresh weight at harvest was unaffected by ethanol treatment, but wine made from treated grapes showed greater colour intensity compared with control grapes

Exogenous ethylene stimulates the long-term expression of genes related to anthocyanin biosynthesis in grape berries

The treatment of grape berries (Vitis vinifera L. cv. Cabernet Sauvignon) with the ethylene-releasing compound, 2-chloroethylphosphonic acid (2-CEPA), at veraison is a method known to enhance grape skin colour. We observed that it produced a 6-fold increase, up to 30 pmol g1 FW, of the cluster internal ethylene compared to untreated controls within the 24 h following treatment. This ethylene upsurge was associated with increased levels of chalcone synthase (CHS) and flavanone 3-hydroxylase (F3H) transcripts, which persisted over the following 20 days. Transcript levels of leucoanthocyanidin dioxygenase (LDOX) and UDP glucose-flavonoid 3-O-glucosyl transferase (UFGT) were similarly enhanced by 2-CEPA, although to a lesser extent. The effect on UFGT was confirmed at the protein level by an immunoblot analysis. The transcript accumulation of dihydroflavonol 4-reductase (DFR) was unaffected by 2-CEPA treatment. Examination of the levels of CHS, F3H and UFGT mRNAs in berries during bunch exposure to ethylene, revealed elevated levels of each transcript within the first 6 h of treatment when compared to nonethylene-treated controls. HPLC analyses of berry skin extracts showed that levels of each of the anthocyanins analysed (delphinidin, cyanidin, petunidin, peonidin and malvidin) increased over the 10 days following the ethylene burst, and decreased thereafter. However, anthocyanin levels at harvest were still higher in ethylene treated grapes than in controls. This data is the first evidence that ethylene triggers gene expression related to anthocyanin synthesis in grapes, and in addition, our results also confirm the existence of other regulatory modes in the anthocyanin biosynthetic pathway