Examinando por Autor "Lovazzano, Carlos"

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    Ítem
    Desiccation Stress Tolerance in Porphyra and Pyropia Species: A Latitudinal Analysis along the Chilean Coast
    (MDPI, 2022-12) Contreras-Porcia, Loretto; Meynard, Andrés; Piña, Florentina; Kumar, Manoj; Lovazzano, Carlos; Núñez, Alejandra; Flores-Molina, María Rosa
    One of the most important factors regulating the distribution and abundance of seaweeds is desiccation, triggered mainly by tidal changes and climatic variation. Porphyra and Pyropia species have evolved multiple strategies to tolerate desiccation stress; however, how these tolerance strategies differ in these species inhabiting different latitudes is still unknown. In this context, we analyzed, in situ, the physiological responses of these species (collected from 18° S to 41° S along the Chilean coast) to desiccation stress using biochemical and molecular analyses. The hyper-arid terrestrial climate of northern Chile, with high evaporation and lack of constant rain determines a very steep increase in desiccation stress in the upper intertidal during low tide for these species. Accordingly, the results showed that, in comparison with the southernmost populations, the Porphyra/Pyropia species from the north zone of Chile (18°–30° S) exhibited higher contents of lipoperoxide and carbonyls (1.6–1.9 fold) together with higher enzymatic activities, including ascorbate peroxidase, catalase, peroxiredoxin, and thioredoxin (2–3-fold). In addition, a substantial expression of cat, prx, and trx transcripts during desiccation was demonstrated, mainly in the northernmost populations. These results provide evidence of (i) significant activation of antioxidant enzymes and transcripts (principally cat and prx); (ii) participation of phenolic antioxidant compounds as a highly plastic physiological strategy to cope with desiccation; and (iii) the activation of the tolerance responses was affected by species latitudinal distribution. Thus, for the first time, this study integrated the biochemical and genetic responses of diverse Porphyra/Pyropia species to better understand their physiological dynamics of tolerance over a wide latitudinal range. © 2022 by the authors.
  • Miniatura
    Ítem
    Differential gene expression in Pyropia columbina (Bangiales, Rhodophyta) under natural hydration and desiccation conditions
    (Pontificia Universidad Católica de Valparaíso, Facultad de Recursos Naturales, Escuela de Ciencias del Mar, 2013) Contreras-Porcia, Loretto; López-Cristoffanini, Camilo; Lovazzano, Carlos; Flores-Molina, María Rosa; Thomas, Daniela; Núñez, Alejandra; Fierro, Camila; Guajardo, Eduardo; Correa, Juan A.; Kube, Michael; Reinhardt, Richard
    RESUMEN. En Zonas Costeras rocosas, la desecación es gatillada porción Cambios Diarios en los Niveles de marea, y la Evidencia indica experimental de Me Distribución de las algas en la zona intermareal no está Relacionada estafa do palabra capacidad, párr tolerar la desecación. En Este Contexto, la Presencia de Pyropia columbina en la zona alta del intermareal sí Explica Por Su excepcional tolerancia fisiológica a la desecación. Este Estudio explora las Vías Metabólicas involucradas en la tolerancia a la desecación en P. columbina, un Través de la Caracterización de do transcriptoma Bajo Condiciones de hidratación contrastantes. Se obtuvó 1410 TER provenientes de dos Librerías de substracción de ADNc de frondas Naturalmente hidratadas y desecadas. Los transcriptomas de emba Librerías contienen transcritos de Diversas Rutas Metabólicas Relacionadas a la tolerancia. Entre el los transcritos expresados ​​15% estan involucrados en la Síntesis de Proteínas, do Procesamiento y degradacion, 14,4% Asociados un Fotosíntesis y cloroplasto, el 13,1% una mitocondrial Respiración and function, 10,6% al metabolism de la Pared Celular y 7,5% a la Actividad ANTIOXIDANTE, Proteínas chaperonas y factors de Defensa (catalasa, tiorredoxina, Proteínas de choque térmico, P450 citocromo). In Ambás Librerías sí DESTACA La Presencia De genes / Proteínas no descritos en algas. Proporciona Información This El Primer Trabajo molecular Que Estudia la tolerancia a desecación en P. columbina y Sus Resultados Ayudan a explicar los patrones clásicos de Distribución descritos párr algas en la zona intermareal. Palabras clave: Pyropia, desecación porción Estrés, EST, macroalgas, transcriptómica, Proteínas.
  • Miniatura
    Ítem
    Response to oxidative stress induced by high light and carbon dioxide (CO2) in the biodiesel producer model Nannochloropsis salina (Ochrophyta, Eustigmatales)
    (Universidad de Valparaíso. Facultad de Ciencias del Mar, 2015) Yangüez, Karen; Lovazzano, Carlos; Contreras-Porcia, Loretto; Ehrenfeld, Nicole
    Due to overconsumption of fossil fuels, microalgae have arrived as an alternative source of biofuel. Looking forward to generate a sustainable process, it is proposed to couple the cultures to CO2 emission sources, reaching in this way higher biomass performance and helping in the way with the capture of carbon released by the combustion processes. Nannochloropsis salina is a microalgae from the Monodopsidaceae family, which is easy to grow and produces high value compounds like essential pigments, polyunsaturated fatty acids and high amounts of lipids. Previous studies showed that adding CO2 to cultures (until 2%) generated an increment in biomass and in the production of fatty acids. However, these conditions also induce acidification of the media, a condition that may promote the generation of oxygen reactive species. In this work, the antioxidant performance of N. salina was studied under different culture conditions involving CO2 through 3 different approaches: analysis of antioxidant enzymatic activities (catalase, ascorbate peroxidase and peroxiredoxine), analysis of gene expression and the quantification of H2O2, phenolic compounds and lipoperoxides (e.g., cell damage marker). The results obtained suggest that an increase in the CO2 concentration in the cultures (15,000 ppm), together with high light (1,000 µmol m-1 s-1) induces an oxidative stress condition in N. salina cells. However, the antioxidant response observed in the microalgae manages to soften this stress, adapting themselves to these conditions without affecting their global performance.