86,617 research outputs found
Identification and characterization of the iridoid synthase involved in oleuropein biosynthesis in olive (Olea europaea) fruits
No full textThe secoiridoids are the main class of specialized metabolites present in olive (Olea europaea L.) fruit. In particular, the secoiridoid oleuropein strongly influences olive oil quality because of its bitterness, which is a desirable trait. In addition, oleuropein possesses a wide range of pharmacological properties, including antioxidant, anti-inflammatory, and anti-cancer activities. In accordance, obtaining high oleuropein varieties is a main goal of molecular breeding programs. Here we use a transcriptomic approach to identify candidate genes belonging to the secoiridoid pathway in olive. From these candidates, we have functionally characterized the olive homologue of iridoid synthase (OeISY), an unusual terpene cyclase that couples an NAD (P)H-dependent 1,4-reduction step with a subsequent cyclization, and we provide evidence that OeISY likely generates the monoterpene scaffold of oleuropein in olive fruits. OeISY, the first pathway gene characterized for this type of secoiridoid, is a potential target for breeding programs in a high value secoiridoid-accumulating species. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc
Seed-Specific Expression of AINTEGUMENTA in Medicago truncatula Led to the Production of Larger Seeds and Improved Seed Germination
No full textThe increase of seed size is of great interest in Medicago spp., to improve germination, seedling vigour and, consequently, early forage yield as well as for optimizing seeding techniques and post-seeding management. This study evaluated the effects of the ectopic expression of the AINTEGUMENTA (ANT) cDNA from Arabidopsis thaliana, under the control of the seed-specific USP promoter from Vicia faba, on seed size, germination and seedling growth in barrel medic (Medicago truncatula Gaertn.). All the transgenic T2 barrel medic lines expressing ANT produced seeds significantly larger than those of control plants. Microscopic analysis on transgenic T3 mature seeds revealed that cotyledon storage parenchyma cells were significantly larger and contained larger storage vacuoles than those of the untransformed control. Moreover, the percentage of germination was significantly higher and germination was more rapid in transgenic than in control seeds. Our results indicate that the seed-specific expression of ANT in barrel medic led to larger seeds and improved seed germination, and revealed a regulatory role for ANT in controlling seed size development. © 2014, Springer Science+Business Media New York
Ampelographic and genetic characterisation of ancestral grapevine (Vitis vinifera L.) accessions present in the Umbria Region (Central Italy)
No full textDuring an ongoing effort to recover and preserve local germplasm, 14 accessions of indigenous minor grapevine (Vitis vinifera L.) cultivars from the Umbria Region, Central Italy, were chosen because they had been neglected and were threatened with extinction. Their phenotypic and genetic characteristics were evaluated through an ampelographic study of their shoots, mature leaves, bunches, and berries and by genomic analysis using an international set of nine microsatellite (simple sequence repeat; SSR) markers (VVS2, VVMD5, VVMD7, VVMD27, VrZAG62, VrZAG79, VVMD25, VVMD28, and VVMD32). Comparisons of the SSR profiles of all 14 accessions with grapevine accessions in several databases permitted the identification of unique genotypes, as well as possible synonyms. Information on these older, neglected cultivars will help to reduce the genetic erosion of grapevine germplasm, improve conservation and possible recovery, and assist in the future production of new, distinctive wines
A synthetic cytokinin primes photosynthetic and growth response in grapevine under ion-independent salinity stress
No full textAiding optimal plant–environment interaction would favor plant resilience against environmental constrains including salt stress. We test the hypothesis that 6-Benzylaminopurine (BAP) primes grapevine’s salt tolerance in vines (Vitis vinifera) received salt water (NaCl 100 mM) through the modulation of gene expression of BAP (AHK4, AHP1) and salt-stress (CAT, APX) inducible genes and morpho-physiological traits. A subgroup of vines had previously (48 h) been primed with BAP (80 mg/L) before salt stress. The gene expressions were 30% (CAT) and 56% (APX) lower in primed salt-stressed vines than that in un-primed. Salt treatment did not increase leaf Na+ but it lowered stomatal conductance (g s), photosynthesis (A), stem water potential (less negative) and photosystem-II efficiency (F v/F m). Chlorophyll-a concentrations were 30% higher in BAP-primed compared to un-primed. Adverse effects of salt were significantly reduced, maintaining high A/g s, F v/F m and growth. After the relief of the stress, the BAP primed vines had a fast recovery
Structural and immunological similarities between high molecular weight zinc ion-dependent p-nitrophenylphosphatase and fructose-1,6-bisphosphate aldolase from bovine liver
No full textHigh molecular weight zinc ion-dependent acid p-nitrophenylphosphatase (HMW-ZnAPase) was purified from bovine liver to homogeneity as judged by native and sodium dodecyl sulfate polyacrylamide gel electrophoresis. The partial sequence of the purified enzyme electroblotted on PVDF membrane reveals a 95% sequence homology with human and bovine liver fructose-1,6-bisphosphate aldolase isozyme B (FALD B). FALD B was isolated from bovine liver using an affinity elution from phosphocellulose column. FALD B from bovine liver shows a native and subunit molecular weight that is indistinguishable from that of HMW-ZnAPase. In addition, an affinity purified antiserum raised in rabbits against purified HMW-ZnAPase cross-reacts with bovine liver FALD B and rabbit muscle isozymes. Despite these similarities, HMW-ZnAPase does not show FALD activity and bovine liver FALD does not display any zinc ion-p-nitrophenylphosphatase activity. These results suggested the existence of structural and immunological similarities between bovine liver HMW-ZnAPase and FALD B. Differences in some amino acid residues in enzyme activity indicate that they may be involved in different biochemical functions. © 2001 Elsevier Science B.V
Life cycle assessment analysis of Alfalfa and corn for biogas production in a farm case study
No full textIn the last years the greenhouse effect has been significantly intensified due to human activities, generating large additional amounts of Greenhouse gases (GHG). The fossil fuels are the main causes of that. Consequently, the attention on the composition of the national fuel mix has significantly grown, and the renewables are becoming a more significant component. In this context, biomass is one of the most important sources of renewable energy with a great potential for the production of energy. The study has evaluated, through an LCA (Life Cycle Assessment) study, the attitude of alfalfa (Medicago sativa) as “no food” biomass alternative to maize silage (corn), in the production of biogas from anaerobic digestion. Considering the same functional unit (1 m3 of biogas from anaerobic digestion) and the same time horizon, alfalfa environmental impact was found to be much comparable to that of corn because it has an impact of about 15% higher than corn considering the total score from different categories and an impact of 5% higher of corn considering only greenhouse gases. Therefore, the analysis shows a similar environmental load in the use of alfalfa biomass in energy production compared to maize. Corn in fact, despite a better yield per hectare and yield of biogas, requires a greater amount of energy inputs to produce 1m3 of biogas, while alfalfa, which requires less energy inputs in its life cycle, has a lower performance in terms of yield. The results show the possibility to alternate the two crops for energy production from an environmental perspective
Genome-Wide Identification of Histone Modification Gene Families in the Model Legume Medicago truncatula and Their Expression Analysis in Nodules
No full textHistone methylation and acetylation are key processes in the epigenetic regulation of plant growth, development, and responses to environmental stimuli. The genes encoding for the enzymes that are responsible for these chromatin post-translational modifications, referred to as histone modification genes (HMGs), have been poorly investigated in Leguminosae species, despite their importance for establishment and activity of nitrogen-fixing nodules. In silico analysis of Medicago truncatula HMGs identified 81 histone methyltransferases, 46 histone demethylases, 64 histone acetyltransferases, and 15 histone deacetylases. MtHMGs were analyzed for their structure and domain composition, and some combinations that were not yet reported in other plant species were identified. Genes have been retrieved from M. truncatula A17 and R108 genotypes as well as M. sativa CADL and Zhongmu No.1; the gene number and distribution were compared with Arabidopsis thaliana. Furthermore, by analyzing the expression data that were obtained at various developmental stages and in different zones of nitrogen-fixing nodules, we identified MtHMG loci that could be involved in nodule development and function. This work sets a reference for HMG genomic organization in legumes which will be useful for functional investigation that is aimed at elucidating HMGs involvement in nodule development and symbiotic nitrogen fixation
Cooling Water Injection and Monitoring System to Efficiently Prevent Fouling in Centrifugal Compressors
No full textThe potential impact of fouling on ethylene plant equipment is huge. Gas polymerization frequently occurs in the cracked gas compressor, leading to efficiency losses and lower production due to unplanned outages. Injecting cooling water in the process gas compressor can help producers reduce fouling by lowering the temperature. Cooling water effectiveness is strongly dependent on water atomization and gas stream interaction. A series of numerical simulations was performed to validate the modeling approach by comparing the simulation results with available experimental data and a test case. The outcome depends on the selection of the appropriate models for heat transfer, particle coupling and injection definition. The goal is to develop an enhanced cooling system analysis, design and monitoring. The results of this investigation allow for an accurate prediction of actual temperature values inside the compressor, through the flow path, with consequent optimal dimensioning of the water injection system ─ more specifically, liquid flow rate, pressure drop and droplet sizes. An advanced stage-by-stage water injection system coupled with fully removable nozzles during compressor operation and a monitor efficiency control can decrease operational costs and the risk of production loss by providing operators with continuously updated equipment performance
Analisi biomolecolare e indici di presenza indiretta: uno strumento utile al riconoscimento specie-specifico di Mustelidi.
No full text- …
