Examinando por Autor "Hinrichsen, Patricio"

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    Análisis de expresión de genes de uva de mesa (Vitis vinífera L.) relacionados con la expansión de la baya en crecimiento
    (Universidad Andrés Bello, 2013) Laiz Rios, Pablo Javier; Hinrichsen, Patricio; Escuela de Ingeniería en Biotecnología
    La uva de mesa es el cultivo frutal de mayor importancia en Chile tanto en superficie cultivada como en retornos por exportaciones, siendo nuestro país uno de los principales productores y exportadores mundiales. Sin embargo, su competitividad en el mercado mundial está en riesgo por diversos factores, como el pago de derechos de propiedad intelectual por el uso de nuevas variedades desarrolladas en el extranjero. El tamaño de la fruta es un valioso rasgo comercial en muchas especies, siendo determinante para la preferencia de los consumidores de uva de mesa. Este hecho determina que éste sea un rasgo clave durante la selección de nuevas variedades. El crecimiento de la baya está determinado tanto por factores genéticos como ambientales, sobre los cuales el desarrollo y rearreglo de la pared celular tienen un rol fundamental. Previo a esta tesis se determinaron mediante RNAseq qué genes se expresan diferencialmente en etapas tempranas del desarrollo de las bayas, en segregantes obtenidos de un cruzamiento de 'Ruby Seedless' x ' Sultanina' (Rx.S), enfocándose particularmente en aquellos genes que participan en el rearreglo de la pared celular, y que presentarían relación al tamaño de la baya. Diversos estudios han sugerido que las expansinas (EXP) son reguladores endógenos del crecimiento celular catalizando la expansión de la pared sin eventos hidrolíticos o transglicolíticos asociados. Por otro lado las xiloglucanos endotransglicosilasa/hidrolasa (XTH) llevan a cabo la transglicosilación de los xiloglucanos, permitiendo un deslizamiento transiente entre las microfibrillas de celulosa. Ambas enzimas participarían en el rearreglo de la pared celular. Por otra parte, el inhibidor de la pectinmetilesterasa (PMEI) es una proteína que actuaría bloqueando el sitio activo de la proteína PME promoviendo la rigidez de la pared celular. El presente estudio determinó el nivel de expresión de los genes VvEXPA8-like, VvEXPA15-like, VvXTH4-like, VvPMEI4 hipotéticamente relacionados al tamaño de la baya en uva de mesa en dos fenotipos contrastantes (baya grande y baya pequeña) mediante PCR en tiempo real (qPCR) en segregantes de la población RxS. Todos los genes mostraron diferentes niveles de expresión, aunque VvEXP A8-like fue el que mostró mayores diferencias entre los fenotipos de baya grande y baya pequeña, con un comportamiento en su expresión muy similar al descrito por la literatura, convirtiéndose en el mejor candidato para la búsqueda de posibles marcadores de selección para este fenotipo.
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    Transcriptome profiling of grapevine seedless segregants during berry development reveals candidate genes associated with berry weight
    (BIOMED CENTRAL, 2016-04) Muñoz-Espinoza, Claudia; Di Genova, Alex; Correa, José; Silva, Romina; Maass, Alejandro; González-Agüero, Mauricio; Orellana, Ariel; Hinrichsen, Patricio
    Background Berry size is considered as one of the main selection criteria in table grape breeding programs. However, this is a quantitative and polygenic trait, and its genetic determination is still poorly understood. Considering its economic importance, it is relevant to determine its genetic architecture and elucidate the mechanisms involved in its expression. To approach this issue, an RNA-Seq experiment based on Illumina platform was performed (14 libraries), including seedless segregants with contrasting phenotypes for berry weight at fruit setting (FST) and 6–8 mm berries (B68) phenological stages. Results A group of 526 differentially expressed (DE) genes were identified, by comparing seedless segregants with contrasting phenotypes for berry weight: 101 genes from the FST stage and 463 from the B68 stage. Also, we integrated differential expression, principal components analysis (PCA), correlations and network co-expression analyses to characterize the transcriptome profiling observed in segregants with contrasting phenotypes for berry weight. After this, 68 DE genes were selected as candidate genes, and seven candidate genes were validated by real time-PCR, confirming their expression profiles. Conclusions We have carried out the first transcriptome analysis focused on table grape seedless segregants with contrasting phenotypes for berry weight. Our findings contributed to the understanding of the mechanisms involved in berry weight determination. Also, this comparative transcriptome profiling revealed candidate genes for berry weight which could be evaluated as selection tools in table grape breeding programs.
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    Transcriptomic study of pedicels from GA3- treated table grape genotypes with different susceptibility to berry drop reveals responses elicited in cell wall yield, primary growth and phenylpropanoids synthesis
    (BioMed Central Ltd., 2020-02) Meneses, Marco; García-Rojas, Miguel; Espinoza, Claudia Muñoz; Valenzuela, Tomás Carrasco; Defilippi, Bruno; González-Agüero, Mauricio; Meneses, Claudio; Infante, Rodrigo; Hinrichsen, Patricio
    Background: Gibberellins (GA3) are the most sprayed growth regulator for table grape production worldwide, increasing berry size of seedless varieties through pericarp cell expansion. However, these treatments also exacerbate berry drop, which has a detrimental effect on the postharvest quality of commercialized clusters. Several studies have suggested that pedicel stiffening caused by GA3 would have a role in this disorder. Nevertheless, transcriptional and phenotypic information regarding pedicel responses to GA3 is minimal. Results: Characterization of responses to GA3 treatments using the lines L23 and Thompson Seedless showed that the former was up to six times more susceptible to berry drop than the latter. GA3 also increased the diameter and dry matter percentage of the pedicel on both genotypes. Induction of lignin biosynthesis-related genes by GA3 has been reported, so the quantity of this polymer was measured. The acetyl bromide method detected a decreased concentration of lignin 7 days after GA3 treatment, due to a higher cell wall yield of the isolated fractions of GA3-treated pedicel samples which caused a dilution effect. Thus, an initial enrichment of primary cell wall components in response to GA3 was suggested, particularly in the L23 background. A transcriptomic profiling was performed to identify which genes were associated with these phenotypic changes. This analysis identified 1281 and 1787 genes differentially upregulated by GA3 in L23 and cv. Thompson Seedless, respectively. Concomitantly, 1202 and 1317 downregulated genes were detected in L23 and cv. Thompson Seedless (FDR < 0.05). Gene ontology analysis of upregulated genes showed enrichment in pathways including phenylpropanoids, cell wall metabolism, xylem development, photosynthesis and the cell cycle at 7 days post GA3 application. Twelve genes were characterized by qPCR and striking differences were observed between genotypes, mainly in genes related to cell wall synthesis. Conclusions: High levels of berry drop are related to an early strong response of primary cell wall synthesis in the pedicel promoted by GA3 treatment. Genetic backgrounds can produce similar phenotypic responses to GA3, although there is considerable variation in the regulation of genes in terms of which are expressed, and the extent of transcript levels achieved within the same time frame. © 2020 The Author(s).
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    Whole genome comparison between table and wine grapes reveals a comprehensive catalog of structural variants
    (BioMed Central Ltd., 2014-01) Di Genova, Alex; Almeida, Andrea M.; Muñoz-Espinoza, Claudia; Vizoso, Paula; Travisany, Dante; Moraga, Carol; Pinto, Manuel; Hinrichsen, Patricio; Orellana, Ariel; Maass, Alejandro
    Background: Grapevine (Vitis vinifera L.) is the most important Mediterranean fruit crop, used to produce both wine and spirits as well as table grape and raisins. Wine and table grape cultivars represent two divergent germplasm pools with different origins and domestication history, as well as differential characteristics for berry size, cluster architecture and berry chemical profile, among others. ‘Sultanina’ plays a pivotal role in modern table grape breeding providing the main source of seedlessness. This cultivar is also one of the most planted for fresh consumption and raisins production. Given its importance, we sequenced it and implemented a novel strategy for the de novo assembly of its highly heterozygous genome. Results: Our approach produced a draft genome of 466 Mb, recovering 82% of the genes present in the grapevine reference genome; in addition, we identified 240 novel genes. A large number of structural variants and SNPs were identified. Among them, 45 (21 SNPs and 24 INDELs) were experimentally confirmed in ‘Sultanina’ and six SNPs in other 23 table grape varieties. Transposable elements corresponded to ca. 80% of the repetitive sequences involved in structural variants and more than 2,000 genes were affected in their structure by these variants. Some of these genes are likely involved in embryo development, suggesting that they may contribute to seedlessness, a key trait for table grapes. Conclusions: This work produced the first structural variants and SNPs catalog for grapevine, constituting a novel and very powerful tool for genomic studies in this key fruit crop, particularly useful to support marker assisted breeding in table grapes.