Examinando por Autor "Lodeyro, Anabella F."

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    ÍtemEmbargo
    Efecto de la expresión de una flavodoxina cianobacteriana en mitocondrias de plantas
    (2023) Pagani, Constanza Elizabet; Lodeyro, Anabella F.; Vicino, Paula
    Tanto el estrés biótico como el abiótico generan un desbalance entre la producción y la neutralización de las especies reactivas del oxígeno (EROs), generando estrés oxidativo en la célula. En cianobacterias y algas, las respuestas frente al estrés oxidativo generalmente consisten en reemplazar los blancos sensibles al estrés por alternativas isofuncionales que no se vean afectados ante el estrés. Un ejemplo es la flavodoxina (Fld), que reemplaza la ferredoxina (Fd). La Fd es una proteína con centros Fe-S que participa en la cadena transportadora de electrones fotosintética (CTEF) y su expresión disminuye en condiciones de estrés oxidativo. La Fld es isofuncional a la Fd, pero en lugar del centro Fe-S tiene un grupo prostético flavina mono nucleótido (FMN). Acepta electrones del fotosistema I (FSI) y permite que el flujo de electrones se mantenga, además de competir con el O2 en reacciones de reducción y así disminuir la producción de EROs. A pesar de que las algas y cianobacterias son ancestros de las plantas, no se encuentra codificada la Fld en el genoma de estas últimas. Al generar plantas transgénicas que expresaban Fld en cloroplastos, se observó un aumento de la resistencia al estrés biótico, abiótico y xenobiótico, lo que demostró la capacidad de la proteína en complementar la deficiencia de Fd, disminuir la producción de EROs en cloroplastos y reestablecer el flujo de electrones fotosintético. La contribución del metabolismo redox de las mitocondrias vegetales en condiciones de estrés no es muy conocida. Existe una diversificada red metabólica asociada a la actividad de los citocromos P450 (CYP), enzimas oxidorreductasas con centros Fe-S que participan en procesos de síntesis de diversos componentes celulares y están involucrados en la protección frente a condiciones adversas, con actividad antioxidante, así como también en procesos de señalización. El dador de electrones para la reducción de los CYP es una Fd específica de mitocondrias denominada adrenodoxina (ADX). Aunque su estructura es diferente a la de las Fd de cloroplastos, es isofuncional y puede ser sustituida in vitro por la Fld. Por lo tanto, se propone que la complementación con dicha proteína en mitocondrias podría tener un impacto favorable en la tolerancia al estrés. Esta hipótesis es puesta a prueba en este trabajo de Tesina utilizando líneas de Arabidopsis y tabaco que expresan Fld en mitocondrias.
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    ÍtemAcceso Abierto
    Expression of a plastid-targeted flavodoxin decreases chloroplast reactive oxygen species accumulation and delays senescence in aging tobacco leaves
    (Frontiers Media, 2018-07-17) Mayta, Martín L.; Lodeyro, Anabella F.; Guiamet, Juan J.; Tognetti, Vanesa B.; Melzer, Michael; Hajirezaei, Mohammad-Reza; Carrillo, Néstor
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    ÍtemAcceso Abierto
    Expression of Flavodiiron Proteins Flv2-Flv4 in Chloroplasts of Arabidopsis and Tobacco Plants Provides Multiple Stress Tolerance
    (MDPI, 2021-01-25) Vicino, Paula; Carrillo, Julieta; Gómez, Rodrigo Lionel; Shahinnia, Fahimeh; Tula, Suresh; Melzer, Michael; Rutten, Twan; Carrillo, Néstor; Hajirezaei, Mohammad-Reza; Lodeyro, Anabella F.; https://orcid.org/0000-0002-8789-0899; https://orcid.org/0000-0001-8236-7647; https://orcid.org/0000-0002-5213-4030
    With the notable exception of angiosperms, all phototrophs contain different sets of flavodiiron proteins that help to relieve the excess of excitation energy on the photosynthetic electron transport chain during adverse environmental conditions, presumably by reducing oxygen directly to water. Among them, the Flv2-Flv4 dimer is only found in β-cyanobacteria and induced by high light, supporting a role in stress protection. The possibility of a similar protective function in plants was assayed by expressing Synechocystis Flv2-Flv4 in chloroplasts of tobacco and Arabidopsis. Flv-expressing plants exhibited increased tolerance toward high irradiation, salinity, oxidants, and drought. Stress tolerance was reflected by better growth, preservation of photosynthetic activity, and membrane integrity. Metabolic profiling under drought showed enhanced accumulation of soluble sugars and amino acids in transgenic Arabidopsis and a remarkable shift of sucrose into starch, in line with metabolic responses of drought-tolerant genotypes. Our results indicate that the Flv2-Flv4 complex retains its stress protection activities when expressed in chloroplasts of angiosperm species by acting as an additional electron sink. The flv2-flv4 genes constitute a novel biotechnological tool to generate plants with increased tolerance to agronomically relevant stress conditions that represent a significant productivity constraint.
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    ÍtemAcceso Abierto
    Leaf senescence: the chloroplast connection comes of age
    (MDPI, 2019-11-12) Mayta, Martín L.; Hajirezaei, Mohammad-Reza; Carrillo, Néstor; Lodeyro, Anabella F.
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    ÍtemAcceso Abierto
    Nitrogen depletion blocks growth stimulation driven by the expression of nitric oxide synthase in tobacco
    (Frontiers Media, 2020-03-20) Nejamkin, Andrés; Foresi, Noelia; Mayta, Martín L.; Lodeyro, Anabella F.; Del Castello, Fiorella; Correa-Aragunde, Natalia; Carrillo, Néstor; Lamattina, Lorenzo
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    Photosynthetic characterization of flavodoxin-expressing tobacco plants reveals a high light acclimation-like phenotype
    (Elsevier, 2020-08-01) Gómez, Rodrigo Lionel; Figueroa, Nicolás; Melzer, Michael; Hajirezaei, Mohammad-Reza; Carrillo, Néstor; Lodeyro, Anabella F.
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    ÍtemAcceso Abierto
    Plastid-targeted Cyanobacterial Flavodiiron proteins maintain carbohydrate turnover and enhance drought stress tolerance in barley
    (Frontiers Media, 2021-02-13) Shahinnia, Fahimeh; Tula, Suresh; Hensel, Goetz; Reiahisamani, Narges; Nasr, Nasrin; Kumlehn, Jochen; Gómez, Rodrigo Lionel; Lodeyro, Anabella F.; Carrillo, Néstor; Hajirezaei, Mohammad-Reza
    Chloroplasts, the sites of photosynthesis in higher plants, have evolved several means to tolerate short episodes of drought stress through biosynthesis of diverse metabolites essential for plant function, but these become ineffective when the duration of the stress is prolonged. Cyanobacteria are the closest bacterial homologs of plastids with two photosystems to perform photosynthesis and to evolve oxygen as a byproduct. The presence of Flv genes encoding flavodiiron proteins has been shown to enhance stress tolerance in cyanobacteria. In an attempt to support the growth of plants exposed to drought, the Synechocystis genes Flv1 and Flv3 were expressed in barley with their products being targeted to the chloroplasts. The heterologous expression of both Flv1 and Flv3 accelerated days to heading, increased biomass, promoted the number of spikes and grains per plant, and improved the total grain weight per plant of transgenic lines exposed to drought. Improved growth correlated with enhanced availability of soluble sugars, a higher turnover of amino acids and the accumulation of lower levels of proline in the leaf. Flv1 and Flv3 maintained the energy status of the leaves in the stressed plants by converting sucrose to glucose and fructose, immediate precursors for energy production to support plant growth under drought. The results suggest that sugars and amino acids play a fundamental role in the maintenance of the energy status and metabolic activity to ensure growth and survival under stress conditions, that is, water limitation in this particular case. Engineering chloroplasts by Flv genes into the plant genome, therefore, has the potential to improve plant productivity wherever drought stress represents a significant production constraint.
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    ÍtemAcceso Abierto
    Providing an additional electron sink by the introduction of cyanobacterial Ffavodiirons enhances growth of A. thaliana under various light intensities
    (Frontiers Media, 2020-06-25) Tula, Suresh; Shahinnia, Fahimeh; Melzer, Michael; Rutten, Twan; Gómez, Rodrigo Lionel; Lodeyro, Anabella F.; Wirén, Nicolaus von; Carrillo, Néstor; Hajirezaei, Mohammad-Reza
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    ÍtemAcceso Abierto
    Suppression of reactive oxygen species accumulation in chloroplasts prevents leaf damage but not growth arrest in salt-stressed tobacco plants
    (Public Library of Science (PLOS), 2016-07-21) Lodeyro, Anabella F.; Giró, Mariana; Poli, Hugo O.; Bettucci, Gabriel; Cortadi, Adriana; Ferri, Alejandro M.; Carrillo, Néstor
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    ÍtemAcceso Abierto
    Targeting of flavodoxin to chloroplasts of mesophyll but not bundle sheath maize cells confers increased drought tolerance
    (Wiley, 2023-10-09) Demarchi, Mariana; Arce, Rocío C.; Campi, Mabel; Pierella Karlusich, Juan J.; Hajirezaei, Mohammad-Reza; Melzer, Michael; Lodeyro, Anabella F.; Chan, Raquel L.; Carrillo, Néstor; https://orcid.org/0009-0009-2702-6183; https://orcid.org/0000-0001-6549-6316; https://orcid.org/0009-0002-2997-9753; https://orcid.org/0000-0003-1739- 4424; https://orcid.org/0000-0002- 9537-0121; https://orcid.org/0000-0002-5213-4030; https://orcid.org/0000-0001-9208-2194; https://orcid.org/0000-0002-3264-0008; https://orcid.org/0000-0002-8612-5503; Dra. Maurino, Verónica
    Abiotic stresses, especially drought, represent the main factor limiting agricultural productivity world-wide. Maize, one of the top crops in terms of food, feed and biofuel production, is a C4 summer monocotyledoneous species grown as a single-cross hybrid displaying high heterosis (conducive to improved grain yield), and high sensitivity to drought stress at different growth stages (Sheoran et al., 2022). Photosynthesis is an early target of most environmental hardships including drought, which inhibits CO2 assimilation associated with stomatal closing. Under such conditions, reducing power generated by the photosynthetic electron transport chain (PETC) cannot be used in the regenerative step of the Calvin cycle, leading to the accumulation of NADPH, over-reduction of the PETC and downregulation of ferredoxin levels (Tognetti et al., 2006). The excess of excitation energy and reducing equivalents are delivered to adventitious acceptors, mostly O2, with the generation of partially reduced and/or activated energy-rich reactive oxygen species (ROS) such as the superoxide anion radical, hydrogen peroxide and singlet oxygen, which act both as toxic compounds and signaling intermediates (Foyer et al., 2017; Dvořák et al., 2021). Oxidative stress is thus an almost universal outcome of environmental adversities. [...]