Browsing by Author "Meyer Regueiro, Carlos José"

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    Análisis del rol de la cutícula en la defensa de la vid ante el hongo necrotrófico Botrytis cinerea
    (2022) Meyer Regueiro, Carlos José; Arce Johnson, Jorge Patricio; Pontificia Universidad Católica de Chile. Facultad de Ciencias Biológicas
    La cutícula es la estructura más externa de todos los tejidos aéreo de los organismos vegetales, por esta razón se encuentra en contacto inmediato con el medio circundante, interactuando con las distintas señales ambientales. Particularmente, es esta estructura la primera barrera que deben sobrepasar los patógenos fúngicos para colonizar el tejido aéreo vegetal. Por esta razón, su rol en la interacción planta-patógeno ha tomado relevancia en los últimos años. Se han propuesto tres mecanismos hipotéticos que podrían explicar las funciones de la cutícula en la interacción planta hongo: (1) Barrera física que impide la penetración del patógeno, (2) fuente de compuestos que afectan el desarrollo del hongo y (3) fuente de efectores percibidos tempranamente por la planta. Dentro del género Vitis, híbridos V. vinifera x V. labrusca presentan mayor grado de resistencia a este patógeno que su contraparte V. vinifera. Basados en la comparación de los componentes de la cutícula de ambas especies se determinó que en los cultivares derivados de V. labrusca existe una mayor acumulación de ácido ursólico, ácido olenólico y heintriacotano, moléculas que otorgan resistencia al hongo al ser asperjadas sobre bayas susceptibles. Este proyecto plantea estudiar la interacción entre B. cinerea y V. vinifera (híbridos V. vinifera x V. Labrusca) para contribuir a dilucidar cuál es el mecanismo de resistencia mediado por las ceras de la cutícula, a través de la caracterización de aspectos fisiológicos del ciclo infectivo del hongo en bayas de vid para dilucidar el componente principal de la resistencia a B. cinerea.
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    Differences in berry primary and secondary metabolisms identified by transcriptomic and metabolic profiling of two table grape color somatic variants
    (2019) Santibáñez, Claudia; Meyer Regueiro, Carlos José; Martínez, Litsy; Moyano, Tomás; Lunn, John; Feil, Regina; Dai, Zhanwu; Carrasco, David; Arroyo García, Rosa; Hilbert,Ghislaine; Renaud, Christel; Delrot, Serge; Manke Nachtigall, Fabiane; Gutiérrez Ilabaca, Rodrigo Antonio; Matus, José Tomás; Gomès, Eric; Arce Johnson, Jorge Patricio
    Anthocyanins are flavonoids responsible for the color of berries in skin-pigmented grapevine (Vitis vinifera L.). Due to the widely adopted vegetative propagation of this species, somatic mutations occurring in meristematic cell layers can be fixed and passed into the rest of the plant when cloned. In this study we focused on the transcriptomic and metabolic differences between two color somatic variants. Using microscopic, metabolic and mRNA profiling analyses we compared the table grape cultivar (cv.) ‘Red Globe’ (RG, with purplish berry skin) and cv. ‘Chimenti Globe’ (CG, with a contrasting reddish berry skin color). As expected, significant differences were found in the composition of flavonoids and other phenylpropanoids, but also in their upstream precursors’ shikimate and phenylalanine. Among primary metabolites, sugar phosphates related with sucrose biosynthesis were less accumulated in cv. ‘CG’. The red-skinned cv. ‘CG’ only contained di-hydroxylated anthocyanins (i.e. peonidin and cyanidin) while the tri-hydroxylated derivatives malvidin, delphinidin and petunidin were absent, in correlation to the reddish cv. ‘CG’ skin coloration. Transcriptomic analysis showed alteration in flavonoid metabolism and terpenoid pathways and in primary metabolism such as sugar content. Eleven flavonoid 3’5’-hydroxylase gene copies were down-regulated in cv. ‘CG’. This family of cytochrome P450 oxidoreductases are key in the biosynthesis of tri-hydroxylated anthocyanins. Many transcription factors appeared down-regulated in cv. ‘CG’ in correlation to the metabolic and transcriptomic changes observed. The use of molecular markers and its confirmation with our RNA-seq data showed the exclusive presence of the null MYBA2 white allele (i.e. homozygous in both L1 and L2 layers) in the two somatic variants. Therefore, the differences in MYBA1 expression seem sufficient for the skin pigmentation differences and the changes in MYBA target gene expression in cv. ‘Chimenti Globe’.
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    Isolation and molecular characterization of MYB60 in Solanum lycopersicum
    (2021) Rodríguez Hoces de la Guardia, Amparo Cecilia; Ugalde, María Beatriz; Lobos Díaz, Valeria Rocío; Lucina Romero-Romero, Jesús; Meyer Regueiro, Carlos José; Inostroza Blancheteau, Claudio; Reyes Diaz, Marjorie; Aquea, Felipe; Arce Johnson, Jorge Patricio
    Stomatal closure is a common adaptation response of plants to the onset of drought condition and its regulation is controlled by transcription factors. MYB60, a transcription factor involved in the regulation of light-induced stomatal opening, has been characterized in arabidopsis and grapevine. In this work, we studied the role of MYB60 homolog SIMYB60 in tomato plants. We identified, isolated, and sequenced the SIMYB60 coding sequence, and found domains and motifs characteristic of other MYB60 proteins. We determined that SlMYB60 is mainly expressed in leaves, and its expression is repressed by abscisic acid. Next, we isolated a putative promoter region containing regulatory elements responsible for guard cell expression and other putative regulatory elements related to ABA repression and vascular tissue expression. Protein localization assays demonstrated that SlMYB60 localizes to the nucleus. Finally, SlMYB60 is able to complement the mutant phenotype of atmyb60-1 in Arabidopsis. Together, these results indicate that SlMYB60 is the homologous gene in tomato and potentially offer a molecular target to improve crops.
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    MYB24 orchestrates terpene and flavonol metabolism as light responses to anthocyanin depletion in variegated grape berries
    (2023) Zhang, Chen; Dai, Zhanwu; Ferrier, Thilia; Orduna, Luis; Santiago, Antonio; Peris, Arnau; Wong, Darren C. J.; Kappel, Christian; Savoi, Stefania; Loyola Muñoz, Rodrigo Esteban; Amato, Alessandra; Kozak, Bartosz; Li, Miaomiao; Liang, Akun; Carrasco, David; Meyer Regueiro, Carlos José; Espinoza, Carmen; Hilbert, Ghislaine; Figueroa-Balderas, Rosa; Cantu, Dario; Arroyo-Garcia, Rosa; Arce-Johnson, Patricio; Claudel, Patricia; Errandonea, Daniel; Rodriguez-Concepcion, Manuel; Duchene, Eric; Huang, Shao-Shan Carol; Castellarin, Simone Diego; Tornielli, Giovanni Battista; Barrieu, Francois; Matus, Jose Tomas
    Variegation is a rare type of mosaicism not fully studied in plants, especially fruits. We examined red and white sections of grape (Vitis vinifera cv. 'Bequignol') variegated berries and found that accumulation of products from branches of the phenylpropanoid and isoprenoid pathways showed an opposite tendency. Light-responsive flavonol and monoterpene levels increased in anthocyanin-depleted areas in correlation with increasing MYB24 expression. Cistrome analysis suggested that MYB24 binds to the promoters of 22 terpene synthase (TPS) genes, as well as 32 photosynthesis/light-related genes, including carotenoid pathway members, the flavonol regulator HY5 HOMOLOGUE (HYH), and other radiation response genes. Indeed, TPS35, TPS09, the carotenoid isomerase gene CRTISO2, and HYH were activated in the presence of MYB24 and MYC2. We suggest that MYB24 modulates ultraviolet and high-intensity visible light stress responses that include terpene and flavonol synthesis and potentially affects carotenoids. The MYB24 regulatory network is developmentally triggered after the onset of berry ripening, while the absence of anthocyanin sunscreens accelerates its activation, likely in a dose-dependent manner due to increased radiation exposure. Anthocyanins and flavonols in variegated berry skins act as effective sunscreens but for different wavelength ranges. The expression patterns of stress marker genes in red and white sections of 'Bequignol' berries strongly suggest that MYB24 promotes light stress amelioration but only partly succeeds during late ripening., MYB24 controls metabolic responses in skin sections of variegated grape berries lacking anthocyanin to cope with high-intensity and UV light stress, promoting terpene and flavonol accumulation.
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    Omics Approaches for Understanding Grapevine Berry Development: Regulatory Networks Associated with Endogenous Processes and Environmental Responses
    (2017) Serrano, A.; Espinoza, C.; Armijo, G.; Inostroza, C.; Poblete, E.; Meyer Regueiro, Carlos José; Arce Medina, Aníbal Andrés; Parada, F.; Santibanez, C.; Arce Johnson, Jorge Patricio