Functional Characterization of Four Olive Squalene Synthases with Respect to the Squalene Content of the Virgin Olive Oil.

The release of new olive cultivars with an increased squalene content in their virgin olive oil is considered an important target in olive breeding programs. In this work, the variability of the squalene content in a core collection of 36 olive cultivars was first studied, revealing two olive cultivars, 'Dokkar' and 'Klon-14', with extremely low and high squalene contents in their oils, respectively. Next, four cDNA sequences encoding squalene synthases (SQS) were cloned from olive.

[Socioeconomic impact of the current management of severe biliary acute pancreatitis: comparative study].

Objetive: Acute pancreatitis of biliary origin is a common gastrointestinal pathology, in which timely management still is the most important. The aims of this research is establish the socioeconomic impact in the current management of severe acute pancreatitis of biliary origin comparing two centers of the third level, one of high socioeconomic population and another of low in Bogotá, Colombia.

Materials And Methods: A retrospective, cross-sectional comparative study was conducted between January 2012 and December 2017, in two hospitals of Bogotá DC.

Carbon supply and water status regulate fatty acid and triacylglycerol biosynthesis at transcriptional level in the olive mesocarp.

The relative contribution of carbon sources generated from leaves and fruits photosynthesis for triacylglycerol biosynthesis in the olive mesocarp and their interaction with water stress was investigated. With this aim, altered carbon source treatments were combined with different irrigation conditions. A higher decrease in mesocarp oil content was observed in fruits under girdled and defoliated shoot treatment compared to darkened fruit conditions, indicating that both leaf and fruit photosynthesis participate in carbon supply for oil biosynthesis being leaves the main source.

Distinct Physiological Roles of Three Phospholipid:Diacylglycerol Acyltransferase Genes in Olive Fruit with Respect to Oil Accumulation and the Response to Abiotic Stress.

Three different cDNA sequences, designated , , and , encoding three phospholipid:diacylglycerol acyltransferases (PDAT) have been isolated from olive ( cv. Picual). Sequence analysis showed the distinctive features typical of the PDAT family and together with phylogenetic analysis indicated that they encode PDAT.

Modification of 13-hydroperoxide lyase expression in olive affects plant growth and results in altered volatile profile.

The C6 aldehydes, alcohols, and the corresponding esters are the most important compounds of virgin olive oil aroma. These C6 volatile compounds are synthesized via the 13-hydroperoxide lyase (13-HPL) branch of the lipoxygenase pathway. In this investigation, a functional analysis of the olive (Olea europaea L.

Chloroplast Lipids Metabolism and Function. A Redox Perspective.

Plant productivity is determined by the conversion of solar energy into biomass through oxygenic photosynthesis, a process performed by protein-cofactor complexes including photosystems (PS) II and I, and ATP synthase. These complexes are embedded in chloroplast thylakoid membrane lipids, which thus function as structural support of the photosynthetic machinery and provide the lipid matrix to avoid free ion diffusion. The lipid and fatty acid composition of thylakoid membranes are unique in chloroplasts and cyanobacteria, which implies that these molecules are specifically required in oxygenic photosynthesis.

The Oleic/Linoleic Acid Ratio in Olive ( L.) Fruit Mesocarp Is Mainly Controlled by and Genes Together With the Different Specificity of Extraplastidial Acyltransferase Enzymes.

Fatty acid composition of olive oil has an important effect on the oil quality to such an extent that oils with a high oleic and low linoleic acid contents are preferable from a nutritional and technological point of view. In the present work, we have first studied the diversity of the fatty acid composition in a set of eighty-nine olive cultivars from the Worldwide Olive Germplasm Bank of IFAPA Cordoba (WOGBC-IFAPA), and in a core collection (Core-36), which includes 28 olive cultivars from the previously mentioned set. Our results indicate that oleic and linoleic acid contents displayed the highest degree of variability of the different fatty acids present in the olive oil of the 89 cultivars under study.

Lipid Composition and Associated Gene Expression Patterns during Pollen Germination and Pollen Tube Growth in Olive (Olea europaea L.).

Pollen lipids are essential for sexual reproduction, but our current knowledge regarding lipid dynamics in growing pollen tubes is still very scarce. Here, we report unique lipid composition and associated gene expression patterns during olive pollen germination. Up to 376 genes involved in the biosynthesis of all lipid classes, except suberin, cutin and lipopolysaccharides, are expressed in olive pollen.

Specialized Functions of Olive FAD2 Gene Family Members Related to Fruit Development and the Abiotic Stress Response.

Three different cDNA sequences, designated OepFAD2-3, OepFAD2-4 and OepFAD2-5, encoding three microsomal oleate desaturases (FAD2) have been isolated from olive (Olea europaea cv. Picual). Sequence analysis and functional expression in yeast of the corresponding cDNAs confirm that they encode microsomal oleate desaturases.

Effect of saline irrigation on physiological traits, fatty acid composition and desaturase genes expression in olive fruit mesocarp.

The effect of salinity on physiological traits, fatty acid composition and desaturase genes expression in fruit mesocarp of olive cultivar Leccino was investigated. Significant reduction of shoot elongation (-12%) during salt treatments (80 mM NaCl) was associated with the translocation of Na in the aerial part. After 75 days of treatment, fruits from each plant were subdivided into four maturation groups (MG, MG, MG, MG) according to ripening degrees.

Transcriptional Regulation of Stearoyl-Acyl Carrier Protein Desaturase Genes in Response to Abiotic Stresses Leads to Changes in the Unsaturated Fatty Acids Composition of Olive Mesocarp.

In higher plants, the stearoyl-acyl carrier protein desaturase (SAD) catalyzes the first desaturation step leading to oleic acid, which can be further desaturated to linoleic and α-linolenic acids. Therefore, SAD plays an essential role in determining the overall content of unsaturated fatty acids (UFA). We have investigated how genes expression and UFA composition are regulated in olive () mesocarp tissue from Picual and Arbequina cultivars in response to different abiotic stresses.

Paraoxonase activities in human follicular fluid: role in follicular maturation.

The paraoxonases (PONs) are antioxidant enzymes associated with beneficial effects against several diseases and some exposures. Little is known, however, about the role of PONs in human reproduction. This work was conducted to investigate whether any association existed between the activities of the PON enzymes (1, 2, and 3) with the follicular size and fertility parameters in assisted reproduction.

Influence of oxygen partial pressure on the characteristics of human hepatocarcinoma cells.

Most of the in vitro studies using liver cell lines have been performed under atmospheric oxygen partial pressure (21% O). However, the oxygen concentrations in the liver and cancer cells are far from this value. In the present study, we have evaluated the influence of oxygen on 1) the tumor cell lines features (growth, steady-state ROS levels, GSH content, activities of antioxidant enzymes, p66 Shc and SOD expressions, metalloproteinases secretion, migration, invasion, and adhesion) of human hepatocellular carcinoma cell lines, and b) the response of the cells to an oxidant stimulus (aqueous leaf extract of the V.

Transcriptional Analysis of Stearoyl-Acyl Carrier Protein Desaturase Genes from Olive (Olea europaea) in Relation to the Oleic Acid Content of the Virgin Olive Oil.

The specific contribution of different stearoyl-ACP desaturase (SAD) genes to the oleic acid content in olive (Olea europaea) fruit has been studied. Toward that end, we isolated three distinct cDNA clones encoding three SAD isoforms from olive (cv. Picual), as revealed by sequence analysis.

Differential Contribution of Endoplasmic Reticulum and Chloroplast ω-3 Fatty Acid Desaturase Genes to the Linolenic Acid Content of Olive (Olea europaea) Fruit.

Linolenic acid is a polyunsaturated fatty acid present in plant lipids, which plays key roles in plant metabolism as a structural component of storage and membrane lipids, and as a precursor of signaling molecules. The synthesis of linolenic acid is catalyzed by two different ω-3 fatty acid desaturases, which correspond to microsomal- (FAD3) and chloroplast- (FAD7 and FAD8) localized enzymes. We have investigated the specific contribution of each enzyme to the linolenic acid content in olive fruit.

Characterization of the paraoxonase system in follicular fluid of women subjected to an ovarian stimulation cycle.

Reactive oxygen species (ROS) and antioxidants are involved in the regulation of reproductive processes. Previous studies in infertile women undergoing an ovarian stimulation cycle have suggested a possible role for ROS in the occurrence of conception in In Vitro Fertilization. In this context the control of the redox balance of follicular fluid becomes essential for reproduction, so that the presence of enzymes with antioxidant activities, such as the paraoxonase (PON) system, would play a role in maintaining this balance.

Glutathione S-transferase activity in follicular fluid from women undergoing ovarian stimulation: role in maturation.

Female infertility involves an emotional impact for the woman, often leading to a state of anxiety and low self-esteem. The assisted reproduction techniques (ART) are used to overcome the problem of infertility. In a first step of the in vitro fertilization therapy women are subjected to an ovarian stimulation protocol to obtain mature oocytes, which will result in competent oocytes necessary for fertilization to occur.

Piper and Vismia species from Colombian Amazonia differentially affect cell proliferation of hepatocarcinoma cells.

There is an increasing interest to identify plant-derived natural products with antitumor activities. In this work, we have studied the effects of aqueous leaf extracts from Amazonian Vismia and Piper species on human hepatocarcinoma cell toxicity. Results showed that, depending on the cell type, the plants displayed differential effects; thus, Vismia baccifera induced the selective killing of HepG2, while increasing cell growth of PLC-PRF and SK-HEP-1.

Virus-induced alterations in primary metabolism modulate susceptibility to Tobacco rattle virus in Arabidopsis.

During compatible virus infections, plants respond by reprogramming gene expression and metabolite content. While gene expression studies are profuse, our knowledge of the metabolic changes that occur in the presence of the virus is limited. Here, we combine gene expression and metabolite profiling in Arabidopsis (Arabidopsis thaliana) infected with Tobacco rattle virus (TRV) in order to investigate the influence of primary metabolism on virus infection.

Stress-dependent regulation of 13-lipoxygenases and 13-hydroperoxide lyase in olive fruit mesocarp.

The effect of different environmental stresses on the expression and enzyme activity levels of 13-lipoxygenases (13-LOX) and 13-hydroperoxide lyase (13-HPL) and on the volatile compounds synthesized by their sequential action has been studied in the mesocarp tissue of olive fruit from the Picual and Arbequina cultivars. The results showed that temperature, light, wounding and water regime regulate olive 13-LOXs and 13-HPL genes at transcriptional level. Low temperature and wounding brought about an increase in LOX and HPL enzyme activities.

Pathogen and Circadian Controlled 1 (PCC1) regulates polar lipid content, ABA-related responses, and pathogen defence in Arabidopsis thaliana.

Pathogen and Circadian Controlled 1 (PCC1) was previously characterized as a regulator of defence against pathogens and stress-activated transition to flowering. Plants expressing an RNA interference construct for the PCC1 gene (iPCC1 plants) showed a pleiotropic phenotype. They were hypersensitive to abscisic acid (ABA) as shown by reduced germination potential and seedling establishment, as well as reduced stomatal aperture and main root length in ABA-supplemented media.

De novo assembly and functional annotation of the olive (Olea europaea) transcriptome.

Olive breeding programmes are focused on selecting for traits as short juvenile period, plant architecture suited for mechanical harvest, or oil characteristics, including fatty acid composition, phenolic, and volatile compounds to suit new markets. Understanding the molecular basis of these characteristics and improving the efficiency of such breeding programmes require the development of genomic information and tools. However, despite its economic relevance, genomic information on olive or closely related species is still scarce.

A cytosolic acyltransferase contributes to triacylglycerol synthesis in sucrose-rescued Arabidopsis seed oil catabolism mutants.

Triacylglycerol (TAG) levels and oil bodies persist in sucrose (Suc)-rescued Arabidopsis (Arabidopsis thaliana) seedlings disrupted in seed oil catabolism. This study set out to establish if TAG levels persist as a metabolically inert pool when downstream catabolism is disrupted, or if other mechanisms, such as fatty acid (FA) recycling into TAG are operating. We show that TAG composition changes significantly in Suc-rescued seedlings compared with that found in dry seeds, with 18:2 and 18:3 accumulating.

Molecular cloning, functional characterization and transcriptional regulation of a 9-lipoxygenase gene from olive.

A lipoxygenase (LOX) cDNA clone (Oep2LOX1) has been isolated from olive fruit (Olea europaea cv. Picual). The deduced amino acid sequence displayed significant similarity to known plant LOX1 sequences.