Expansión y senescencia foliar en soja (Glycine max L.): cambios redox y su modulación por condiciones de estrés .

Tesis (Grado Doctor en Ciencias Biológicas)--Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Lugar de Trabajo: Instituto de Fisiología y Recursos Genéticos Vegetales- IFRGV-CIAP -Instituto Nacional de Tecnología Agropecuaria - Facultad de Ciencias Exactas, Físicas y Naturales. Universidad Nacional de Córdoba. 2016 . 163 h. + CD. tabls.; grafs.; figuras. Contiene Referencia Bibliográfica y Publicaciones Derivadas de la Tesis. Abstract en español e inglés.El estado redox celular, determinado principalmente por la relación entre generación y degradación de especies reactivas del oxígeno (EROs), tiene un rol clave en la homeostasis celular, la modulación del crecimiento y desarrollo, y, en las respuestas a condiciones de estrés ambiental. Particularmente durante la senescencia y bajo diferentes condiciones de estrés ocurren aumentos en la generación de EROs, lo que puede devenir en procesos oxidativos deletéreos conocido como estrés oxidativo. Sin embargo, se ha reconocido las capacidad de las EROs de actuar como moléculas señales, modulando vías de señalización implicadas en el crecimiento y desarrollo de las plantas. La hipótesis propuesta en este trabajo fue que las diferentes etapas del desarrollo foliar en soja (expansión y madurez/senescencia) van acompañadas de cambios redox diferenciales, los cuales son alterados por condiciones de estrés y participan en la modulación de las respuestas al estrés. El objetivo principal fue estudiar los cambios redox que ocurren durante las etapas de expansión y madurez/senescencia foliar, y su relación con la modulación de las respuestas al estrés. Los cambios observados en las tasas de expansión y superficie foliar estuvieron acompañados por una dinámica diferencial en los niveles de .O2- y similares niveles de H2O2. Los mayores niveles se asociaron a una mayor velocidad de expansión, principalmente en la condición control. La expansión foliar pudo ser modulada con la aplicación externa de H2O2 y MnCl2, indicando la participación de las EROs en el desarrollo foliar. Los parámetros relacionados al funcionamiento fotosintético evidenciaron diferencias dinámicas significativas entre los tratamientos con una disminución marcada a partir del final de la expansión en plantas bajo estrés. El sistema antioxidante enzimático presentó comportamientos diferenciales a lo largo del desarrollo foliar y entre ambos tratamientos. Particularmente isoformas cloroplásticas de SOD respondieron tanto al estadio de desarrollo como a la condición de estrés. Los antioxidantes no enzimáticos estuvieron asociados principalmente a la edad foliar. La expresión de los genes de las enzimas relacionadas al estado redox, evidenciaron un control diferencial asociado tanto a la edad foliar como al estrés, con patrones diferenciales de expresión de sus isoformas en los distintos compartimentos celulares. En base a los resultados obtenidos proponemos que el estado redox mediado por la generación/degradación de EROs tiene participación directa sobre el desarrollo foliar, modulando la expansión, con consecuencias sobre la madurez/senescencia. Condiciones estresantes generan cambios en el estado redox que se traducen en efectos deletéreos sobre el proceso.Fil: Parola, Rodrigo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Escuela de Biología; Argentin

A transcriptomic approach to the metabolism of tetrapyrrolic photosensitizers in a marine annelid

Funding Information: Funding: The authors also acknowledge DPGM (the Portuguese General Directorate for Marine Policy) for funding the MARVEN project (ref. FA_05_2017_007). The Portuguese Foundation for Science and Technology (FCT) funded project WormALL (PTDC/BTA-BTA/28650/2017), which includes the contract attributed to M.D. and the fellowship attributed to A.P.R. UCIBIO and LAQV are financed by national funds from FCT, UID/Multi/04378/2020 and UID/QUI/50006/2020, respectively. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.The past decade has seen growing interest in marine natural pigments for biotechnological applications. One of the most abundant classes of biological pigments is the tetrapyrroles, which are prized targets due their photodynamic properties; porphyrins are the best known examples of this group. Many animal porphyrinoids and other tetrapyrroles are produced through heme metabolic pathways, the best known of which are the bile pigments biliverdin and bilirubin. Eulalia is a marine Polychaeta characterized by its bright green coloration resulting from a remarkably wide range of greenish and yellowish tetrapyrroles, some of which have promising photodynamic properties. The present study combined metabolomics based on HPLC-DAD with RNA-seq transcriptomics to investigate the molecular pathways of porphyrinoid metabolism by comparing the worm’s proboscis and epidermis, which display distinct pigmentation patterns. The results showed that pigments are endogenous and seemingly heme-derived. The worm possesses homologs in both organs for genes encoding enzymes involved in heme metabolism such as ALAD, FECH, UROS, and PPOX. However, the findings also indicate that variants of the canonical enzymes of the heme biosynthesis pathway can be species-and organ-specific. These differences between molecular networks contribute to explain not only the differential pigmentation patterns between organs, but also the worm’s variety of novel endogenous tetrapyrrolic compounds.publishersversionpublishe

The complexity of porphyrin-like pigments in a marine annelid sheds new light on haem metabolism in aquatic invertebrates

PTDC/MAR-BIO/0113/2014. UID/Multi/04378/2019. UID/QUI/50006/2019. SFRH/BD/120030/2016. SFRH/BD/109462/2015. IF/00265/2015.True green pigments in the animal kingdom are scarce and are almost invariably porphyrinoids. Endogenous porphyrins resulting from the breakdown of haem are usually known as “bile pigments”. The pigmentation of intertidal Polychaeta has long gained attention due to its variety and vivid patterning that often seems incompatible with camouflage, as it occurs with Eulalia viridis, one of the few truly green Polychaeta. The present study combined UV and bright-field microscopy with HPLC to address the presence and distribution of pigments in several organs. The results showed two major types of porphyrin-like pigments, yellowish and greenish in colour, that are chiefly stored as intraplasmatic granules. Whereas the proboscis holds yellow pigments, the skin harbours both types in highly specialised cells. In their turn, oocytes and intestine have mostly green pigments. Despite some inter-individual variation, the pigments tend to be stable after prolonged storage at −20 °C, which has important implications for future studies. The results show that, in a foraging predator of the intertidal where melanins are circumscribed to lining the nervous system, porphyrinoid pigments have a key role in protection against UV light, in sensing and even as chemical defence against foulants and predators, which represents a remarkable adaptive feature.publishersversionpublishe

Paraoxonase-1 is related to inflammation, fibrosis and PPAR delta in experimental liver disease

<p>Abstract</p> <p>Background</p> <p>Paraoxonase-1 (PON1) is an antioxidant enzyme synthesized by the liver. It protects against liver impairment and attenuates the production of the pro-inflammatory monocyte chemoattractant protein-1 (MCP-1). We investigated the relationships between hepatic PON1 and MCP-1 expression in rats with liver disease and explored the possible molecular mechanisms involved.</p> <p>Methods</p> <p>CCl₄was administered for up to 12 weeks to induce liver damage. Serum and hepatic levels of PON1 and MCP-1, their gene and protein expression, nuclear transcription factors, and histological and biochemical markers of liver impairment were measured.</p> <p>Results</p> <p>High levels of PON1 and MCP-1 expression were observed at 12^thweek in the hepatocytes surrounding the fibrous septa and inflammatory areas. CCl₄-administered rats had an increased hepatic PON1 concentration that was related to decreased gene transcription and inhibited protein degradation. Decreased PON1 gene transcription was associated with PPARδ expression. These changes were accompanied by increased hepatic MCP-1 concentration and gene expression. There were significant direct relationships between hepatic PON1 and MCP-1 concentrations (P = 0.005) and between PON1 and the amount of activated stellate cells (P = 0.001).</p> <p>Conclusion</p> <p>Our results from this experimental model suggest a hepato-protective role for PON1 against inflammation, fibrosis and liver disease mediated by MCP-1.</p

Antifungal protection by endophytic bacteria in legumes

PosterPeanut and chickpea are two of the major crops cultivated in Argentina Two different fungal diseases generate substantial yield losses annually Ascochyta rabiei causal agent of aschochyta blight and Thecaphora frezii is the causal agent of peanut smut Beneficial bacteria have the potential to provide antifungal effects that could be used as bioproducts to control these diseases Our project aims to identify endophytic bacteria with antifungal effects in vitro and in vivo.Instituto de Fisiología y Recursos Genéticos VegetalesFil: Valetti, Lucio. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Valetti, Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Sardo, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Sardo, María Florencia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Posada, Gisella. Instituto Superior Albert Sabin; ArgentinaFil: Gonzalez, Pablo. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Gonzalez, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Estudios Agropecuarios (UDEA) ; ArgentinaFil: Parola, Rodrigo. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Parola, Rodrigo. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Estudios Agropecuarios (UDEA) ; ArgentinaFil: Paredes, Juan Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Paredes, Juan Andrés. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Monguillot, Joaquín Humberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Monguillot, Joaquín Humberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Ruiz, O.A. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Tecnológico de Chascomús (INTECH); Argentna. Universidad Nacional de San Martín; ArgentinaFil: Guzzo, María Carla. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Guzzo, María Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Estudios Agropecuarios (UDEA) ; ArgentinaFil: Monteoliva, Mariela Ines. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Monteoliva, Mariela Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Estudios Agropecuarios (UDEA) ; Argentin

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19

Background: We previously reported that impaired type I IFN activity, due to inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity or to autoantibodies against type I IFN, account for 15–20% of cases of life-threatening COVID-19 in unvaccinated patients. Therefore, the determinants of life-threatening COVID-19 remain to be identified in ~ 80% of cases. Methods: We report here a genome-wide rare variant burden association analysis in 3269 unvaccinated patients with life-threatening COVID-19, and 1373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. Among the 928 patients tested for autoantibodies against type I IFN, a quarter (234) were positive and were excluded. Results: No gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7, with an OR of 27.68 (95%CI 1.5–528.7, P = 1.1 × 10−4) for biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR = 3.70[95%CI 1.3–8.2], P = 2.1 × 10−4). This enrichment was further strengthened by (1) adding the recently reported TYK2 and TLR7 COVID-19 loci, particularly under a recessive model (OR = 19.65[95%CI 2.1–2635.4], P = 3.4 × 10−3), and (2) considering as pLOF branchpoint variants with potentially strong impacts on splicing among the 15 loci (OR = 4.40[9%CI 2.3–8.4], P = 7.7 × 10−8). Finally, the patients with pLOF/bLOF variants at these 15 loci were significantly younger (mean age [SD] = 43.3 [20.3] years) than the other patients (56.0 [17.3] years; P = 1.68 × 10−5). Conclusions: Rare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie life-threatening COVID-19, particularly with recessive inheritance, in patients under 60&nbsp;years old

Interactions between soybean, Bradyrhizobium japonicum and Soybean mosaic virus: the effects depend on the interaction sequence

The symbiotic interaction between soybean and nitrogen-fixing rhizobia can lead to plant growth promotion and induced systemic responses. Symbiotic interactions may increase tolerance/resistance to abiotic/biotic stress conditions, but are also sensitive to environmental conditions. Soybean mosaic virus (SMV), which is transmitted by seed and aphids, severely affects crop yields in many areas of the world, consequently virus infection may precede rhizobium infection or vice versa in the field. With the hypothesis that sequence of interaction is a key determinant of the resulting responses; growth, primary metabolism and defence responses were evaluated in different interaction sequences. Results showed that vegetative growth was promoted by Bradyrhizobium japonicum (Bj) inoculation and drastically impaired by SMV infection. The negative effect of SMV single infection on soybean growth parameters was correlated with photosynthesis decrease, sugar accumulation, oxidative damage, and increases in salicylic acid levels. Bj inoculation partially reversed virus-induced symptoms, mainly at Bj-SMV sequence. However, this symptom attenuation did not correlate with less virus accumulation. Nodulation was negatively affected by SMV, particularly when virus infection was previous to Bj inoculation (SMV-Bj). Defence related hormones (salicylic acid (SA)/jasmonic acid (JA)) and the expression of defence-related genes were dependent on the sequence of tripartite interaction. The present study showed that the sequence of the tripartite interaction among soybean, Bj and SMV determinates the tolerance/susceptibility to SMV infection, through changes in the defence mechanism and metabolic alteration.Instituto de Fisiología y Recursos Genéticos VegetalesFil: Andreola, Sofía. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; Argentina. Unidad de Estudios Agropecuarios (UDEA- CONICET); ArgentinaFil: Rodriguez, Marianela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; Argentina. Unidad de Estudios Agropecuarios (UDEA- CONICET); ArgentinaFil: Parola, Rodrigo. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; Argentina. Unidad de Estudios Agropecuarios (UDEA- CONICET); ArgentinaFil: Alemano, Sergio. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Físico-Químicas y Naturales. Departamento de Ciencias Naturales; ArgentinaFil: Lascano, Ramiro. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Cátedra de Fisiología Vegetal; Argentin

TOR and SnRK1 signaling pathways in plant response to abiotic stresses: Do they always act according to the "yin-yang" model?

Plants are sessile photo-autotrophic organisms continuously exposed to a variety of environmental stresses. Monitoring the sugar level and energy status is essential, since this knowledge allows the integration of external and internal cues required for plant physiological and developmental plasticity. Most abiotic stresses induce severe metabolic alterations and entail a great energy cost, restricting plant growth and producing important crop losses. Therefore, balancing energy requirements with supplies is a major challenge for plants under unfavorable conditions. The conserved kinases target of rapamycin (TOR) and sucrose-non-fermenting-related protein kinase-1 (SnRK1) play central roles during plant growth and development, and in response to environmental stresses; these kinases affect cellular processes and metabolic reprogramming, which has physiological and phenotypic consequences. The "yin-yang" model postulates that TOR and SnRK1 act in opposite ways in the regulation of metabolic-driven processes. In this review, we describe and discuss the current knowledge about the complex and intricate regulation of TOR and SnRK1 under abiotic stresses. We especially focus on the physiological perspective that, under certain circumstances during the plant stress response, the TOR and SnRK1 kinases could be modulated differently from what is postulated by the "yin-yang" concept.Instituto de Fisiología y Recursos Genéticos VegetalesFil: Rodriguez, Marianela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; Argentina. Unidad de Estudios Agropecuarios (UDEA- CONICET); ArgentinaFil: Parola, Rodrigo. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; Argentina. Unidad de Estudios Agropecuarios (UDEA- CONICET); ArgentinaFil: Andreola, Sofia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; Argentina. Unidad de Estudios Agropecuarios (UDEA- CONICET); ArgentinaFil: Pereyra, Cintia. Fundación para Investigaciones Biológicas Aplicadas. Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET); ArgentinaFil: Martínez-Noël, Giselle. Fundación para Investigaciones Biológicas Aplicadas. Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET); Argentin