14 research outputs found

    Transcriptome Profiles of Contrasting Potato (Solanum tuberosum L.) Genotypes under Water Stress

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    Indexación: ScopusThe potato is susceptible to water stress at all stages of development. We examined four clones of tetraploid potato, Cardinal, Desirée, Clone 37 FB, and Mije, from the germplasm bank of the National Institute of Agricultural Research (INIA) in Chile. Water stress was applied by suspending irrigation at the beginning of tuberization. Stomatal conductance, and tuber and plant fresh and dry weight were used to categorize water stress tolerance. Cardinal had a high susceptibility to water stress. Desirée was less susceptible than Cardinal and had some characteristics of tolerance. Mije had moderate tolerance and Clone 37 FB had high tolerance. Differential gene expression in leaves from plants with and without water stress were examined using transcriptome sequencing. Water stress-susceptible Cardinal had the fewest differentially expressed genes at 101, compared to Desirée at 1867, Clone 37 FB at 1179, and Mije at 1010. Water stress tolerance was associated with upregulation of the expression of transcription factor genes and genes involved in osmolyte and polyamine biosynthesis. Increased expression of genes encoding late embryogenesis abundant (LEA) and dehydrin proteins along with decreased expression of genes involved in nitrate assimilation and amino acid metabolism were found for clones showing water stress tolerance. The results also show that a water deficit was associated with reduced biotic stress responses. Additionally, heat shock protein genes were differentially expressed in all clones except for highly susceptible Cardinal. Together, the gene expression study demonstrates variation in the molecular pathways and biological processes in response to water stress contributing to tolerance and susceptibility. © 2019 by the authors.https://www.mdpi.com/2073-4395/9/12/84

    Impact of structural modifications at positions 13, 16 and 17 of 16 b -( m -carbamoylbenzyl)-estradiol on 17 b -hydroxysteroid dehydrogenase type 1 inhibition and estrogenic activity

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    The chemical synthesis of four stereoisomers (compounds 5a–d) of 16ß-(m-carbamoylbenzyl)-estradiol, a potent reversible inhibitor of 17ß-hydroxysteroid dehydrogenase type 1 (17ß-HSD1), and two intermediates (compounds 3a and b) was performed. Assignment of all nuclear magnetic resonance signals confirmed the stereochemistry at positions 13, 16 and 17. Nuclear overhauser effects showed clear correlations supporting a C-ring chair conformation for 5a and b and a C-ring boat conformation for 5c and d. These compounds were tested as 17ß-HSD1 inhibitors and to assess their proliferative activity on estrogen-sensitive breast cancer cells (T-47D) and androgen-sensitive prostate cancer cells (LAPC-4). Steroid derivative 5a showed the best inhibitory activity for the transformation of estrone to estradiol (95, 82 and 27%, at 10, 1 and 0.1 µM, respectively), but like the other isomers 5c and d, it was found to be estrogenic. The intermediate 3a, however, was weakly estrogenic at 1 µM, not at all at 0.1 µM, and showed an interesting inhibitory potency on 17ß-HSD1 (90, 59 and 22%, at 10, 1 and 0.1 µM, respectively). As expected, no compound showed an androgenic activity. The binding modes for compounds 3a and b, 5a–d and CC-156 were evaluated from molecular modeling. While the non-polar interactions were conserved for all the inhibitors in their binding to 17ß-HSD1, differences in polar interactions and in binding conformational energies correlated to the inhibitory potencies

    Data Mining Nitrogen-Responsive Gene Expression for Source–Sink Relations and Indicators of N Status in Potato

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    Potato tuber yields depend on nitrogen (N) supply, which affects source–sink relations. Transcriptome sequencing of the foliar source using a single field trial identified gene expression responsive to 180 kg N ha−1. The expression of N-responsive genes was further analyzed in the next stage using a NanoString nCounter over an expanded number of foliar samples from seven field trials with varying N rates, sites, and cultivars. Least absolute shrinkage and selection operator (LASSO) regression models of gene expression predictive of yield, total plant N uptake, and tuber-specific gravity (proxy for dry matter) were built. Genes in the LASSO model for yield were associated with source–sink partitioning. A key gene regulating tuberization and senescence, StSP6A Flowering locus T, was found in the LASSO model predicting tuber yield, but not the other models. An aminotransferase involved in photorespiratory N assimilation and amino acid biosynthesis was found in all LASSO models. Other genes functioning in amino acid biosynthesis and integration of sulfur (S) and N metabolism were also found in the yield prediction model. The study provides insights on N responses in foliage of potato plants that affect source–sink partitioning. Additionally, N-responsive genes predictive of yield are candidate indicators of N status

    Verticillium dahliae disease resistance and the regulatory pathway for maturity and tuberization in potato

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    Posted online: 19 Sept 2017Verticillium dahliae Kleb. is a pathogenic fungus causing wilting, chlorosis and early dying in potato. Genetic mapping of resistance to V. dahliae was done using a diploid population of potato. The major quantitative trait locus (QTL) for Verticillium resistance was found on chromosome 5. The StCDF1 gene controlling earliness of maturity and tuberization was mapped within the interval. Another QTL on chromosome 9 co-localised with the Ve2 Verticillium wilt resistance gene marker. Epistasis analysis indicated that the loci on chromosomes 5 and 9 had a highly significant interaction, and that StCDF1 functioned downstream of Ve2. The StCDF1 alleles were sequenced and found to encode StCDF1.1 and StCDF1.3. Interaction between the Ve2 resistance allele and the StCDF1.3 was demonstrated, but not for StCDF1.1. Genome-wide expression QTL (eQTL) analysis was carried out and genes with eQTL at the StCDF1 and Ve2 loci were both found to have similar functions involving the chloroplast, including photosynthesis, which declines in both maturity and Verticillium wilt. Among the GO terms that were specific to genes with eQTL at the Ve2, but not the StCDF1 locus, were those associated with fungal defense. These results suggest that Ve2 controls fungal defense and reduces early dying in Verticillium wilt through affecting genetic pathway controlling tuberization timing

    A decade of progress on anisotropic mesh adaptation for computational fluid dynamics

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    International audienceIn the context of scientific computing, the mesh is used as a discrete support for the considered numerical methods. As a consequence, the mesh greatly impacts the efficiency, the stability and the accuracy of numerical methods. The goal of anisotropic mesh adaptation is to generate a mesh which fits the application and the numerical scheme in order to achieve the best possible solution. It is thus an active field of research which is progressing continuously. This review article proposes a synthesis of the research activity of the INRIA Gamma3 team in the field of anisotropic mesh adaptation applied to inviscid flows in computational fluid dynamics since 2000. It shows the evolution of the theoretical and numerical results during this period. Finally, challenges for the next decade are discussed
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