Publications by authors named "Pilar Lopez-Gresa"

Carotenoids are photoprotectant pigments and precursors of hormones such as strigolactones (SL). Carotenoids are produced in plastids from geranylgeranyl diphosphate (GGPP), which is diverted to the carotenoid pathway by phytoene synthase (PSY). In tomato (Solanum lycopersicum), three genes encode plastid-targeted GGPP synthases (SlG1 to SlG3) and three genes encode PSY isoforms (PSY1 to PSY3).

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New strategies of control need to be developed with the aim of economic and environmental sustainability in plant and crop protection. Metabolomics is an excellent platform for both understanding the complex plant-pathogen interactions and unraveling new chemical control strategies. GC-MS-based metabolomics, along with a phytohormone analysis of a compatible and incompatible interaction between tomato plants and f.

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Article Synopsis
  • - Citrus exocortis viroid (CEVd) affects citrus trees, and its impact has also been studied in tomatoes, causing ribosomal stress similar to the effects of the hormone ethylene.
  • - The study examines how CEVd infection interacts with ethylene in specially developed tomato mutants that are insensitive to ethylene, looking at their infection susceptibility and defensive responses.
  • - Findings reveal that these ethylene-insensitive mutants show greater susceptibility to CEVd, increased expression of defense and ethylene genes, and notable ribosomal stress, highlighting the significant role of ethylene in disease progression.
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We have analysed the salt tolerance of two endemic halophytes of the genus , with high conservation value. In the present study, seed germination and growth parameters as well as different biomarkers-photosynthetic pigments, mono and divalent ion contents-associated to salt stress were evaluated in response to high levels of NaCl. The study was completed with an untargeted metabolomics analysis of the primary compounds including carbohydrates, phosphoric and organic acids, and amino acids, identified by using a gas chromatography and mass spectrometry platform.

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is a genus represented in the Iberian Peninsula by numerous halophytic species that are affected in nature by salinity, and often by prolonged drought episodes. Responses to water deficit have been studied in four Mediterranean species, previously investigated regarding salt tolerance mechanisms. The levels of biochemical markers, associated with specific responses-photosynthetic pigments, mono- and divalent ions, osmolytes, antioxidant compounds and enzymes-were determined in the control and water-stressed plants, and correlated with their relative degree of stress-induced growth inhibition.

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The essential oil fraction obtained from the rind of spp. is rich in chemical compounds of interest for the food and perfume industries, and therefore has been extensively studied during the last decades. In this manuscript, we provide a comprehensive review of the volatile composition of this oil fraction and rind extracts for the 10 most studied species: (sweet orange), (mandarin), (grapefruit), (pummelo), (lemon), (citron), (lime), (bitter orange), (bergamot orange), and (yuzu).

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  • Fool's watercress has been identified as a promising new crop with significant antioxidant properties, outpacing traditional vegetables like celery and parsley.
  • Research analyzed 25 wild populations and measured its antioxidant activity through the DPPH method and total phenolic content (TPC), finding high levels of quercetin, which makes up a large portion of its phenolics.
  • The findings highlight the importance of geographical factors in the plant's antioxidant properties, suggesting potential directions for future breeding and selection programs.
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Background: Aroma profile and carotenoids content of melon flesh are two important aspects influencing the quality of this fruit that have been characterized using only selected genotypes. However, the extant variability of the whole species remains unknown.

Results: A complete view of the volatile/carotenoid profiles of melon flesh was obtained analyzing 71 accessions, representing the whole diversity of the species.

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A series of tetrahydroisoquinolines functionalized with carbamates is reported here as highly selective ligands on the dopamine D2 receptor. These compounds were selected by means of a molecular modeling study. The studies were carried out in three stages: first an exploratory study was carried out using combined docking techniques and molecular dynamics simulations.

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  • Tomato plants with the NahG transgene, which prevents salicylic acid (SA) buildup, exhibited severe disease symptoms when infected with Citrus Exocortis Viroid (CEVd) or Tomato Spotted Wilt Virus (TSWV), compared to the regular Money Maker plants.
  • The use of acibenzolar-S-methyl, an agent that activates defenses downstream of the SA pathway, enhanced the resistance of NahG tomato plants to these viruses.
  • Despite the lack of SA, NahG plants showed an earlier and stronger production of certain defense compounds and proteins, and produced higher levels of ethylene, highlighting the significance of SA in tomato plant defense against CEVd and TSWV.
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Article Synopsis
  • * Researchers focused on the role of silencing-related genes that are similar to those in Arabidopsis thaliana, tracking their activity during infections with the ToMV virus and CEVd viroid in tomatoes.
  • * Results showed that SA and GA treatments significantly induced specific genes, particularly ToDCL2 and ToDCL4, suggesting that the enhanced resistance to RNA pathogens may stem from the activation of RNA silencing pathways through these compounds.
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Viroids are single-stranded, circular, noncoding RNAs that infect plants, causing devastating diseases. In this work, we employed 2D DIGE, followed by MS identification, to analyze the response of tomato plants infected by Citrus exocortis viroid (CEVd). Among the differentially expressed proteins detected, 45 were successfully identified and classified into different functional categories.

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(1)H nuclear magnetic resonance (NMR)-based metabolomics has been applied to study the compatible interaction between tomato plants and Tomato Mosaic Virus (ToMV). A detailed time course of metabolic fingerprinting of ToMV-inoculated and non-inoculated systemically infected tomato leaves has provided a fundamental understanding of the metabolic state of the plant not only in response to ToMV infection, but also under various physiological conditions. By this analytical platform a total of 32 metabolites including amino/organic acids, sugars, phenylpropanoids, flavonoids and other miscellaneous compounds were detected.

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Introduction: Plants utilise various defence mechanisms against their potential biotic stressing agents such as viroids, viruses, bacteria or fungi and abiotic environmental challenges. Among them metabolic alteration is a common response in both compatible and incompatible plant-pathogen interactions. However, the identification of metabolic changes associated with defence response is not an easy task due to the complexity of the metabolome and the plant response.

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Two new meroterpenoids, terretonins E and F (1, 2), together with three known compounds, aurantiamine (3), linoleic acid, and uridine, were isolated as fermentation products of the marine-derived fungus Aspergillus insuetus, which was associated with the sponge Petrosia ficiformis. Structures of all isolates were elucidated employing spectroscopic methods, mainly by two-dimensional NMR techniques. Compounds 1-3 showed activity as inhibitors of the mammalian mitochondrial respiratory chain.

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Chemical analysis of the secondary metabolite pattern of the sacoglossan mollusc Elysia cf. expansa, collected along South Indian coasts, showed the presence of the typical Caulerpa-derived sesquiterpene caulerpenyne (1) and two new minor co- occurring metabolites, the compounds dihydrocaulerpenyne (4) and expansinol (5). The chemical characterization of these molecules, structurally related to 1, is reported.

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Bioassay-guided fractionation of the organic extract derived from the terrestrial fungus Penicillium coalescens led to the isolation of the known mycotoxin (-)-botryodiplodin (1) and eight new structurally related analogues (2-9). The structures of the novel compounds were determined by MS and NMR studies, including 1D and 2D NMR. A likely biogenetic pathway from the aldehydic open form of 1 (C7 unit, U1) is proposed for these metabolites.

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Paraherquamide H (1) and paraherquamide I (2), two new compounds of the paraherquamide (PHQ) family, together with the already known paraherquamide A (3), paraherquamide B (4), paraherquamide E (5), VM55596 (N-oxide paraherquamide) (6), paraherquamide VM55597 (7), and five known diketopiperazines (8-12) have been isolated from the culture broth of Penicillium cluniae Quintanilla. The structure of 1 and 2, on the basis of NMR and MS analysis, was established. It is worth noticing that, in both cases, an unusual oxidative substitution in C-16 was found, which had only previously been detected in PHQ 7.

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Tomato plants infected with the citrus exocortis viroid exhibited strongly elevated levels of a compound identified as 2,5-dihydroxybenzoic acid (gentisic acid, GA) 5-O-beta-D-xylopyranoside. The compound accumulated early in leaves expressing mild symptoms from both citrus exocortis viroid-infected tomato, and prunus necrotic ringspot virus-infected cucumber plants, and progressively accumulated concomitant with symptom development. The work presented here demonstrates that GA, mainly associated with systemic infections in compatible plant-pathogen interactions [Bellés, J.

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The capacity of inhibition of the mammalian mitochondrial respiratory chain of brevioxime 5a, a natural insecticide compound isolated from Penicillium brevicompactum culture broth, and another 15 analogue compounds, other oximes 5b and 5c; two diastereomeric pyrrolidines 1c' and 1c' '; five pyrrolines 3c', 3c' ' (diastereomers between them), 3a, 3b, and 6; two oxazines 4c' and 4c' ' (also diastereomers between them); and four pyrrol derivatives 7-10, are analyzed in this paper. Compounds 3b, 3c', 3c' ', 4c', 4c' ', 5b, 5c, 6, and 10 were found to be inhibitors of the integrated electron transfer chain (NADH oxidase activity) in beef heart submitochondrial particles (SMP), establishing that all of them except compound 3b and 6 only affected to complex I of the mitochondrial respiratory chain. The most potent product was 5b, with an IC50 of 0.

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Circumdatin H (1), a new alkaloid from the culture broth of Aspergillus ochraceus, has been isolated, together with a known circumdatin, circumdatin E (2) and other known compounds: flavacol (3) and stephacidin A (4). The structure of 1 was established on the basis of chemical and spectral evidence. All of these alkaloids showed biological activity as inhibitors of the mammalian mitochondrial respiratory chain.

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The induction of mutagenic and cytotoxic effects by simple phenolics, including catechol (CAT), 3,4-dihydroxyphenylacetic acid (DOPAC), hydroquinone (HQ), and 2,5-dihydroxyphenylacetic (homogentisic) acid (HGA), appears to occur through an oxidative mechanism based on the ability of these compounds to undergo autoxidation, leading to quinone formation with the production of reactive oxygen species. This is supported by the detection of such adverse effects in plate assays using Escherichia coli tester strains deficient in the OxyR function, but not in OxyR(+) strains. The OxyR protein is a redox-sensitive regulator of genes encoding antioxidant enzymes including catalase and alkyl hydroperoxide reductase, which would eliminate hydrogen peroxide.

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