Search results for "secondary metabolism"
showing 10 items of 42 documents
Effects of irrigation on fruit ripening behavior and metabolic changes in olive
2012
Olive (Olea europaea, cv Leccino) fruits grown under different water regimes were analyzed by metabolomics and specific transcript accumulation analyses. The fruit from non-irrigated (rain-fed) and irrigated trees cultivated under field conditions, with a seasonal water amount equivalent to the calculated crop evapotranspiration (ETc) was compared in the last developmental phase and, in particular, at commercial harvest. Metabolomics (GC-MS) analysis identified several hundred metabolites in ripe mesocarp, 46 of which showed significantly different contents in the rain-fed and irrigated samples. Some compounds involved in primary metabolism (carbohydrates, amino acids, organic acids) and se…
MOLECULAR AND METABOLIC ANALYSES IN DEVELOPING OLIVE FRUIT IN RELATION TO DIFFERENT WATER REGIMES
2011
Despite the global economic importance of olive (Olea europaea L.), little is known about the molecular and metabolic changes during fruit development and the modulation of quality-related metabolic pathways during drought stress. In this work, we report the expression pattern of genes involved in important pathways of secondary metabolism (polyphenols, terpenoids) during fruit development in rainfed or fully irrigated olive plants. Phenolic compounds represent a complex mixture in both olive fruits and oil. The interest on these compounds is due to their demonstrated anti-atherogenic and anti-cancerogenic effects providing to the olive oil important nutraceutical properties. Several parame…
Toxic Proteins and Peptides
1994
Many animals produce poisonous substances which, even at a relatively low dose, are deleterious or lethal to other organisms, including man. They may serve on the one hand to disable or kill prey, or on the other hand as a protection or defence against predators. These substances are mostly produced by special glands, and both poison reservoirs and specialized structures for delivering the secretion, e.g. stings or modified mouthparts or fangs, are usually also present. In accordance with the aims of this book, we will deal with the comparative biochemistry of the animal toxins as natural products with special structures and functions; a discussion of the mechanisms of their pharmacological…
Metabolic relation of cyanobacteria to aromatic compounds
2018
Cyanobacteria, also known as blue-green (micro)algae, are able to sustain many types of chemical stress because of metabolic adaptations that allow them to survive and successfully compete in a variety of ecosystems, including polluted ones. As photoautotrophic bacteria, these microorganisms synthesize aromatic amino acids, which are precursors for a large variety of substances that contain aromatic ring(s) and that are naturally formed in the cells of these organisms. Hence, the transformation of aromatic secondary metabolites by cyanobacteria is the result of the possession of a suitable “enzymatic apparatus” to carry out the biosynthesis of these compounds according to cellular requireme…
Transcription of genes in the biosynthetic pathway for fumonisin mycotoxins is epigenetically and differentially regulated in the fungal maize pathog…
2012
ABSTRACT When the fungal pathogen Gibberella moniliformis (anamorph, Fusarium verticillioides ) colonizes maize and maize-based products, it produces class B fumonisin (FB) mycotoxins, which are a significant threat to human and animal health. FB biosynthetic enzymes and accessory proteins are encoded by a set of clustered and cotranscribed genes collectively named FUM, whose molecular regulation is beginning to be unraveled by researchers. FB accumulation correlates with the amount of transcripts from the key FUM genes, FUM1 , FUM21 , and FUM8 . In fungi in general, gene expression is often partially controlled at the chromatin level in secondary metabolism; when this is the case, the deac…
Study of the potential toxicity of commercial crispy breads by evaluation of bioaccessibility and bioavailability of minor Fusarium mycotoxins
2011
Abstract Enniatins (ENs) are bioactive compounds produced by the secondary metabolism of several Fusarium strains and known to have several biological activities, such as acting as enzyme inhibitors, antifungal and antibacterial agents, and immunomodulatory substances. This study has investigated the ENs bioaccessibility, spiked in commercial wheat crispy bread at 1.5 and 3.0 μmol/g concentrations, their transepithelial transport and bioavailability using Caco-2 cells as a model of the human intestinal epithelium. The content (%) of the four ENs contained in the gastric fluid has resulted variable from 69% to 91%, considering the two concentrations assayed. The mean bioaccessibility data fo…
A chemical approach for the reduction of beauvericin in a solution model and in food systems.
2014
Abstract Beauvericin (BEA) is a bioactive compound produced by the secondary metabolism of several Fusarium strains with a strong antibacterial, antifungal, and insecticidal activities. This study evaluated the reduction of BEA added at 25 mg/kg in phosphate buffer saline (PBS) solutions at pH of 4, 7 and 10, or to different cereal products (kernels and flours) by the bioactive compounds phenyl isothiocyanate (PITC) and benzyl isothiocyanate (BITC). The concentration of the mycotoxin was evaluated using liquid chromatography coupled to the diode array detector (LC-DAD). In solution, BEA reduction ranged from 9% to 94% on a time-dependent fashion and lower pH levels resulted in higher BEA re…
Introduction to the Toxins Special Issue on Toxicological Effects of Mycotoxin on Target Cells.
2020
Mycotoxins are toxic secondary metabolites produced by filamentous fungi from Fusarium, Alternaria and Penicillium spp [...]
Stress responses in citrus peel: Comparative analysis of host responses to Huanglongbing disease and puffing disorder
2015
Abstract A comparison between transcriptomic responses to puffing disorder and Huanglongbing disease was conducted to decipher differences and similarities in gene and pathway regulation induced by abiotic (puffing) and biotic stresses (Huanglongbing) in citrus peel tissues. We functionally analyzed two previously published datasets: the first obtained for the study of puffing disorder using an Affymetrix citrus microarray and the second consisting of a deep sequencing analysis of symptomatic responses to Huanglongbing disease. Transcriptomic data were mined using bioinformatic tools to highlight genes and pathways playing a key role in modulating responses to different types of stress in c…
Genes of Secondary Metabolism: Differential Expression in Plants and In Vitro Cultures and Functional Expression in Genetically Transformed Microorga…
1989
Plants had to develop strategies for defence against microorganisms and herbivores during evolution. The evolution of chemical defence, i.e. the production of the so-called secondary products can be regarded as one of the most important means in this context (Swain 1977, Rosenthal and Janzen 1979, Wink 1988). Since secondary metabolites evolved as biologically active compounds, it is not surprising that man has found a use for many of them, e.g. as medicinal agents, flavours, spices, colours, stimulants, hallucinogens, or pesticides. As a consequence, quite a number of secondary plant products are of economical importance.