The chemical composition of the essential oil extracted from fresh leaves of Lippia citriodora (Verbenaceae) was analyzed by GC-FID and GC–MS in May, when growth rates are maximal, and in September, in full bloom. In both samples the main... more
The chemical composition of the essential oil extracted from fresh leaves of Lippia citriodora (Verbenaceae) was analyzed by GC-FID and GC–MS in May, when growth rates are maximal, and in September, in full bloom. In both samples the main constituents were geranial, neral and limonene constituting 66.3% of the total essential oil yield in May and increasing to 69% in September. Their individual percentage values, however, changed considerably for geranial and neral decreasing from 38.7 to 26.8% and from 24.5 to 21.8%, respectively, and for limonene increasing from 5.8 to 17.7%. All other components remained more or less unchanged both qualitatively and quantitatively. FT-IR spectrometry was also applied for the qualitative determination of the main components.
Research Interests:
The development of resistance to hormone therapy caused by both fulvestrant and tamoxifen promotes autophagy with concomitant apoptosis evasion, rendering cells capable of surviving and growing. The fact that resistance also triggers ERBB... more
The development of resistance to hormone therapy caused by both fulvestrant and tamoxifen promotes autophagy with concomitant apoptosis evasion, rendering cells capable of surviving and growing. The fact that resistance also triggers ERBB family signaling pathways, which are poorly inhibited by tyrosine kinase inhibitors might attribute to cells’ aggressiveness. It is obvious that the development of endocrine therapy resistance involves a complex interplay between deregulated ERBB signaling and autophagy that may be considered in clinical practice.
Research Interests:
Research Interests: Botany, Photosynthesis, Salinity, Sugar, photosystem I, and 2 moreJaponica and Photosystem II(Japonica and Photosystem II)
(Japonica and Photosystem II)
Mitochondrial structure and function is emerging as a major contributor to neuromuscular disease, highlighting the need for the complete elucidation of the underlying molecular and pathophysiological mechanisms. Following a forward... more
Mitochondrial structure and function is emerging as a major contributor to neuromuscular disease, highlighting the need for the complete elucidation of the underlying molecular and pathophysiological mechanisms. Following a forward genetics approach with N-ethyl-N-nitrosourea (ENU)-mediated random mutagenesis, we identified a novel mouse model of autosomal recessive neuromuscular disease caused by a splice-site hypomorphic mutation in a novel gene of unknown function, DnaJC11. Recent findings have demonstrated that DNAJC11 protein co-immunoprecipitates with proteins of the mitochondrial contact site (MICOS) complex involved in the formation of mitochondrial cristae and cristae junctions. Homozygous mutant mice developed locomotion defects, muscle weakness, spasticity, limb tremor, leucopenia, thymic and splenic hypoplasia, general wasting and early lethality. Neuropathological analysis showed severe vacuolation of the motor neurons in the spinal cord, originating from dilatations of...
The storage cells in the cotyledons of air-dried Phaseolus vulgaris seeds contain large quantities of polysaccharides, protein and to a lesser extent, lipids. A single multilobed nucleus occurs in the centre of each storage cell... more
The storage cells in the cotyledons of air-dried Phaseolus vulgaris seeds contain large quantities of polysaccharides, protein and to a lesser extent, lipids. A single multilobed nucleus occurs in the centre of each storage cell surrounded by large starch grains, small plastids and mitochondria whilst the cytoplasm occupies the narrow channels between the various organelles. The cell walls are composed of two layers, the outer, cellulosic, and inner, non-cellulosic, and the latter serves as a polysaccharide store. After hydration for 24 hours the storage cells respond to in vitro culturing, on solid medium (Murashige and Skoog, 1962) containing 2,4-D, kinetin and coconut milk, by producing a callus tissue which, when routinely subcultured, continues to grow for a potentially indefinite period. No organogenesis was observed in the callus cultures during the one year of cultivation. The callus appears on the adarial side of the cotyledon (which is in contact with the medium) and, init...
Research Interests:
Aim of study: To assess the role of polyphenol oxidase (PPO), peroxidase (POD) and indole-3-acetic acid oxidase (IAAox) during adventitious rooting (Ar) in semi-hardwood cuttings of the easy-to-root olive cv. ‘Arbequina’ and the... more
Aim of study: To assess the role of polyphenol oxidase (PPO), peroxidase (POD) and indole-3-acetic acid oxidase (IAAox) during adventitious rooting (Ar) in semi-hardwood cuttings of the easy-to-root olive cv. ‘Arbequina’ and the difficult-to-root cv. ‘Kalamata’. Simultaneously, a histological study was carried out in both cultivars to investigate the tissue related with Ar development.Area of study: The rooting experiments were carried out in ‘Kostelenos’ nurseries (Troizinia, Greece) and in Agricultural University of Athens.Material and methods: Plant material to set up the experiment was collected from current year shoots from 15-year-old mother plants of ‘Arbequina’ and ‘Kalamata’ at three different seasons (summer, autumn and spring). The auxin indole-3-butyric acid (IBA) at 2000 mg L-1 was used as rooting inducer.Main results: Analysis revealed that ‘Kalamata’ had significantly higher enzymatic activities before experiment onset and during Ar compared to ‘Arbequina’. Control cu...
Research Interests:
Under certain conditions, leaf cystoliths of Parietaria judaica can decompose, and the CO2 released can be photosynthetically assimilated. This process lowers surplus energy and protects the photosynthetic apparatus.
Research Interests:
Research Interests:
In many plant species, carbon-calcium inclusion (calcium oxalate crystals or cystoliths containing calcium carbonate) formation is a fundamental part of their physiology even necessary for normal growth and development. Despite the... more
In many plant species, carbon-calcium inclusion (calcium oxalate crystals or cystoliths containing calcium carbonate) formation is a fundamental part of their physiology even necessary for normal growth and development. Despite the long-standing studies on carbon-calcium inclusions, the alterations in their properties during leaf development and their possible association with the maturation of the photosynthetic machinery have not been previously examined. In order to acquire more insights into this subject, we examined three of the most common species bearing abundant inclusions of different types, i.e., Amaranthus hybridus, Vitis vinifera, and Parietaria judaica. Results of our study showed that, irrespective of species and type of inclusion, similar patterns in the alterations of their properties are observed during leaf maturation, except for some differences in cell differentiation and distribution between raphides and druses in Vitis vinifera. As expected, inclusion formation...
Research Interests:
Research Interests:
ABSTRACT
Research Interests:
Land plants face the perpetual dilemma of using atmospheric carbon dioxide for photosynthesis and losing water vapours, or saving water and reducing photosynthesis and thus growth. The reason behind this dilemma is that this simultaneous... more
Land plants face the perpetual dilemma of using atmospheric carbon dioxide for photosynthesis and losing water vapours, or saving water and reducing photosynthesis and thus growth. The reason behind this dilemma is that this simultaneous exchange of gases is accomplished through the same minute pores on leaf surfaces, called stomata. In a recent study we provided evidence that pigweed, an aggressive weed, attenuates this problem exploiting large crystals of calcium oxalate as dynamic carbon pools. This plant is able to photosynthesize even under drought conditions, when stomata are closed and water losses are limited, using carbon dioxide from crystal decomposition instead from the atmosphere. Abscisic acid, an alarm signal that causes stomatal closure seems to be implicated in this function and for this reason we named this path "alarm photosynthesis." The so-far "enigmatic", but highly conserved and widespread among plant species calcium oxalate crystals seem t...
Research Interests:
Research Interests:
Research Interests:
Notch may behave as an oncogene or a tumor suppressor gene in lung cancer cells. Notch receptor undergoes cleavage by enzymes, including γ-secretase, generating the active Notch intracellular domain (NICD). The aim of the present study... more
Notch may behave as an oncogene or a tumor suppressor gene in lung cancer cells. Notch receptor undergoes cleavage by enzymes, including γ-secretase, generating the active Notch intracellular domain (NICD). The aim of the present study was to investigate the effect of DAPT, a γ-secretase inhibitor, in non-small cell lung cancer (NSCLC) cells, as well as the impact of epidermal growth factor (EGF) that is over-expressed by NSCLC cells, on Notch signaling. H23, A549, H661 and HCC827 human NSCLC cell lines were used, expressing various NICD and EGF receptor (EGFR) protein levels. DAPT decreased the number of H661 cells in a concentration-dependent manner, while it had a small effect on H23 and A549 cells and no effect on HCC827 cells that carry mutated EGFR. Notch inhibition did not affect the stimulatory effect of EGF on cell proliferation, while EGF prevented DAPT-induced NICD decrease in H23 and H661 cells. The type of cell death induced by DAPT seems to depend on the cell type. Our...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
... Anastasia Markantonatou1, Dimitra Daferera2, Vasiliki Liakoura3, Petros Tarantilis2, Moschos Polissiou2, Constantinos Fasseas1 1Laboratory of Electron Microscopy, 3Laboratory of Plant Physiology and Morphology, Department of... more
... Anastasia Markantonatou1, Dimitra Daferera2, Vasiliki Liakoura3, Petros Tarantilis2, Moschos Polissiou2, Constantinos Fasseas1 1Laboratory of Electron Microscopy, 3Laboratory of Plant Physiology and Morphology, Department of Agricultural ... [4] KC Nicolaou, The art and ...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Botany, Photosynthesis, Plant Biology, Biology, Plasmodesmata, and 13 moreEcology, Medicine, Tree Physiology, Sugar, Boron, Tree, Trees, Phloem, Forestry Sciences, Boric Acid, Olea, Mannitol, and Plant Leaves(Ecology, Medicine, Tree Physiology, Sugar, Boron, Tree, Trees, Phloem, Forestry Sciences, Boric Acid, Olea, Mannitol, and Plant Leaves)
(Ecology, Medicine, Tree Physiology, Sugar, Boron, Tree, Trees, Phloem, Forestry Sciences, Boric Acid, Olea, Mannitol, and Plant Leaves)
Research Interests:
Uncommon, viruslike symptoms (yellowing, line patterns, leaf deformation, and necrosis), were observed in spinach fields in the Marathon area, Greece in 2004. Seedlings from the same seed lot, grown in the greenhouse, also developed the... more
Uncommon, viruslike symptoms (yellowing, line patterns, leaf deformation, and necrosis), were observed in spinach fields in the Marathon area, Greece in 2004. Seedlings from the same seed lot, grown in the greenhouse, also developed the same viruslike symptoms, indicating that the causal agent(s) of the disorder is seed-transmissible. Spinach seedlings of the same variety but a different lot and herbaceous indicators (Chenopodium quinoa, C. amaranticolor, Sonchus oleraceus, and Nicotiana benthamiana) were mechanically inoculated with infected material. Spinach developed yellowing or necrotic spots whereas indicators showed variety of symptoms including mosaic, vein banding, and necrotic lesions. Virus purifications, double-stranded RNA extractions, cloning, and sequencing (2,3) followed by a combination of molecular (reverse transcription [RT]-PCR and immunocapture RT-PCR) and serological (ELISA) techniques with antisera provided by Dr. Avgelis were performed as described (4), verif...
Research Interests:
Research Interests:
DOI: 10.1111/j.1469-8137.2009.02731.xCommentary p 505
Research Interests: Biology, Cell Biology, Mitochondria, Medicine, Gene expression, and 15 moreArabidopsis thaliana, Biological Sciences, Growth, Cytochrome C, Arabidopsis, Genes, Molecular cloning, Germination, Enzyme activity, Inflorescences, Mutants, Gas Exchange, Hypocotyl, Mitochondrion, and Mitochondrial Proteins
Genetic functional analyses of mutants in plant genes encoding cellulose synthases (CesAs) have suggested that cellulose deposition requires the activity of multiple CesA proteins. Here, a genetic screen has led to the identification of... more
Genetic functional analyses of mutants in plant genes encoding cellulose synthases (CesAs) have suggested that cellulose deposition requires the activity of multiple CesA proteins. Here, a genetic screen has led to the identification of thanatos (than), a semi-dominant mutant of Arabidopsis thaliana with impaired growth of seedlings. Homozygous seedlings of than germinate and grow but do not survive. In contrast to other CesA mutants, heterozygous plants are dwarfed and display a radially swollen root phenotype. Cellulose content is reduced by approximately one-fifth in heterozygous and by two-fifths in homozygous plants, showing gene-dosage dependence. Map-based cloning revealed an amino acid substitution (P578S) in the catalytic domain of the AtCesA3 gene, indicating a critical role for this residue in the structure and function of the cellulose synthase complex. Ab initio analysis of the AtCesA3 subdomain flanking the conserved proline residue predicted that the amino acid substitution to serine alters protein secondary structure in the catalytic domain. Gene dosage-dependent expression of the AtCesA3 mutant gene in wild-type A. thaliana plants resulted in a than dominant-negative phenotype. We propose that the incorporation of a mis-folded CesA3 subunit into the cellulose synthase complex may stall or prevent the formation of functional rosette complexes.
Research Interests: Biochemistry, Computational Biology, Biology, Medicine, Cellulose, and 15 moreArabidopsis thaliana, Biological Sciences, Mutation, Plant growth, ATP synthase, Gene Dosage, Arabidopsis, Phenotype, Embryonic Development, Fourier transform infrared spectroscopy, Chromosome segregation, Amino Acid Sequence, Amino Acid Substitution Rates, Molecular Sequence Data, and alleles
Research Interests:
... Anna Assimakopoulou a , Constantin D. Holevas b & Konstantinos Fasseas c pages 1014-1033. ... The possibility of using the root ferric chelate reductase activity for selecting Fe efficient rootstocks has been investigated for... more
... Anna Assimakopoulou a , Constantin D. Holevas b & Konstantinos Fasseas c pages 1014-1033. ... The possibility of using the root ferric chelate reductase activity for selecting Fe efficient rootstocks has been investigated for several fruit crops (Römheld and Marschner, 198343. ...
Research Interests: Chemistry, Horticulture, Plant Biology, Hydroponics, Biology, and 10 morePlant Nutrition, Phosphorus, Plant, Nitrogen, Zinc, Iron, Soil sciences, Prunus, Rootstock, and Sodium Bicarbonate(Plant Nutrition, Phosphorus, Plant, Nitrogen, Zinc, Iron, Soil sciences, Prunus, Rootstock, and Sodium Bicarbonate)
(Plant Nutrition, Phosphorus, Plant, Nitrogen, Zinc, Iron, Soil sciences, Prunus, Rootstock, and Sodium Bicarbonate)
Research Interests:
Research Interests:
Research Interests:
ABSTRACT The dorsiventral, amphistomatic, hairy leaf of Pelargonium odoratissimum was lacking the variety of the anatomical features considered advantages for the Mediterranean plant life compared to the leaf of most Mediterranean... more
ABSTRACT The dorsiventral, amphistomatic, hairy leaf of Pelargonium odoratissimum was lacking the variety of the anatomical features considered advantages for the Mediterranean plant life compared to the leaf of most Mediterranean xerophytes. Conversely, it had a well-equipped and intensely functioning secretory apparatus. Light, scanning, and transmission electron microscopy were employed to investigate the leaf structure while histochemical reactions traced the nature of the secreted metabolites. The numerous trichomes of the leaf were very active in producing phenolics, terpenes, and flavonoids mixed in a fragrant essential oil accumulated in an ovoid chamber at the top of each secreting hair. In-vitro cell cultures may be used for the production of novel compounds from low-cost precursors.
Research Interests:
ABSTRACT The anatomy of the dorsiventral, amphistomatic leaf of Papaver rhoeas was investigated. It was a simple structure possessing large epidermal cells having their vacuole impregnated with glycoproteins which varied in texture,... more
ABSTRACT The anatomy of the dorsiventral, amphistomatic leaf of Papaver rhoeas was investigated. It was a simple structure possessing large epidermal cells having their vacuole impregnated with glycoproteins which varied in texture, forming a dense, hard core in the middle of the vacuole. Slender rays of cisternae radiated from the dense central core to the cell wall. Thin-walled palisade cells presented a unique, lobed shape probably creating larger surfaces for gas exchange. Mesophyll cells secreted phenolics, condensed tannins, alkaloids, terpene containing steroids and sesquiterpenes. P. rhoeas although being a therophyte, has adopted some structural features common in mediterranean phanerophytes.
Research Interests:
Research Interests:
Carbonic anhydrase (CA) (EC 4.2.1.1) is a widespread enzyme catalyzing the reversible hydration of CO 2 to bicarbonate, a reaction that participates in many biochemical and physiological processes. Mesorhizobium loti , the microsymbiont... more
Carbonic anhydrase (CA) (EC 4.2.1.1) is a widespread enzyme catalyzing the reversible hydration of CO 2 to bicarbonate, a reaction that participates in many biochemical and physiological processes. Mesorhizobium loti , the microsymbiont of the model legume Lotus japonicus , possesses on the symbiosis island a gene (msi040) encoding an α-type CA homologue, annotated as CAA1. In the present work, the CAA1 open reading frame from M. loti strain R7A was cloned, expressed, and biochemically characterized, and it was proven to be an active α-CA. The biochemical and physiological roles of the CAA1 gene in free-living and symbiotic rhizobia were examined by using an M. loti R7A disruption mutant strain. Our analysis revealed that CAA1 is expressed in both nitrogen-fixing bacteroids and free-living bacteria during growth in batch cultures, where gene expression was induced by increased medium pH. L. japonicus plants inoculated with the CAA1 mutant strain showed no differences in top-plant tr...
Research Interests: Biochemistry, Bacteriology, Carbon Dioxide, Biomass, Biology, and 15 moreMedicine, Gene expression, Biological Sciences, Lotus, Nitrogen Fixation, Molecular cloning, Nitrogenase, Carbonic anhydrase, Alphaproteobacteria, Amino Acid Sequence, Mesorhizobium, Molecular Sequence Data, Lotus japonicus, Medical and Health Sciences, and Bicarbonates
Research Interests:
ABSTRACT Two microscopic techniques were used for monitoring the changes that occur during the pyrolysis of Pinus halepensis needles at 100, 200, 250, 300, 350, 400 and 500°C. The changes were monitored by transmission light microscopy... more
ABSTRACT Two microscopic techniques were used for monitoring the changes that occur during the pyrolysis of Pinus halepensis needles at 100, 200, 250, 300, 350, 400 and 500°C. The changes were monitored by transmission light microscopy (LM) and stereoscopy. The following were observed with increasing temperature: (1) deformation of the transverse section; (2) loss of the cuticle layer and cracking of the outer layer; (3) degradation of lignin (a basic component of pine needles); and (4) tar and char formation on the external surface. These changes were attributed to chemical and physical phenomena during the pyrolysis procedure.
Research Interests:
Research Interests:
A novel, Gram-negative, non-motile, non-sporulating, rod-shaped bacterium isolated from a viscous two-phase olive-oil mill waste (‘alpeorujo’) is described. The strain, designated AW-6T, is an obligate aerobe, forming irregular, pigmented... more
A novel, Gram-negative, non-motile, non-sporulating, rod-shaped bacterium isolated from a viscous two-phase olive-oil mill waste (‘alpeorujo’) is described. The strain, designated AW-6T, is an obligate aerobe, forming irregular, pigmented creamy white colonies. The pH and temperature ranges for growth were pH 5–8 and 5–45 °C, with optimal pH and temperature for growth of pH 6–7 and 28–32 °C, respectively. Strain AW-6T was chemo-organotrophic and utilized mostly d(+)-glucose, protocatechuate and d(+)-xylose, followed by l-cysteine, d(−)-fructose, d(+)-galactose, l-histidine, lactose, sorbitol and sucrose. Menaquinone-7 was detected in the respiratory chain of strain AW-6T. The major fatty acids of strain AW-6T were C16 : 1 ω7c and/or iso-C15 : 0 2-OH, iso-C15 : 0, iso-C17 : 0 3-OH and C16 : 0. The closest phylogenetic relative of strain AW-6T was clone BIti35 (89.7 % 16S rRNA gene sequence similarity), while Sphingobacterium thalpophilum DSM 11723T was the closest recognized relative...
Research Interests: Evolutionary Biology, Microbiology, Food Science, Medical Microbiology, Biology, and 15 moreOlive Oil, Medicine, Greece, Phylogeny, Fatty acids, Movement, Temperature, Quinones, Amino Acids, Carbohydrate metabolism, Industrial Waste, Ribosomal DNA, Plant Oils, Molecular Sequence Data, and bacteroidetes
A novel Gram-negative, motile, nonsporulating, rod-shaped bacterium isolated from alkaline sludge-like wastes (‘alpeorujo’ or ‘alperujo’) of two-phase olive oil extraction is described. The strain, designated AW-7T, is an obligate aerobe... more
A novel Gram-negative, motile, nonsporulating, rod-shaped bacterium isolated from alkaline sludge-like wastes (‘alpeorujo’ or ‘alperujo’) of two-phase olive oil extraction is described. The strain, designated AW-7T, is an obligate aerobe that is halotolerant (tolerating up to 15 % w/v NaCl), sugar-tolerant (tolerating up to 45 % and 60 % w/v (+)-d-glucose and maltose respectively; these are the highest concentrations tolerated by any known members of the Bacteria domain) and alkalitolerant (growing at a broad pH range of 5–11). Strain AW-7T is chemo-organotrophic. Ubiquinone-9 was detected in the respiratory chain of strain AW-7T. The major fatty acids present are C18 : 1 ω7c, C16 : 0, C19 : 0 cyclo ω8c, C12 : 0 3-OH and C16 : 1 ω7c/iso-C15 : 0 2-OH. Based on 16S rRNA gene sequence analysis, strain AW-7T showed almost equal phylogenetic distances from Zymobacter palmae (95.6 % similarity) and Carnimonas nigrificans (95.4 % similarity). In addition, low DNA–DNA relatedness values wer...
Research Interests: Evolutionary Biology, Microbiology, Medical Microbiology, Biology, Medicine, and 15 morePhylogeny, Glucose, Fatty acids, Nucleic acid hybridization, Bacteria, Osmotic pressure, Quinones, Industrial Waste, Ribosomal DNA, Hydrogen-Ion Concentration, Sodium Chloride, Organic Chemicals, Nucleic Acid Conformation, Olea, and Molecular Sequence Data
Research Interests:
Research Interests:
We present new information on the parasitoids (Hymenoptera: Braconidae: Aphidiinae) of aphids infesting cotton, tobacco, citrus, and cereal agroecosystems in southeastern Europe. Nineteen species are keyed and illustrated with scanning... more
We present new information on the parasitoids (Hymenoptera: Braconidae: Aphidiinae) of aphids infesting cotton, tobacco, citrus, and cereal agroecosystems in southeastern Europe. Nineteen species are keyed and illustrated with scanning electron micrographs and line drawings. The aphidiines presented in this work have been identified from 18 aphid taxa. Furthermore, 96 original parasitoid–aphid–plant associations are presented. Cotton, tobacco, and citrus agroecosystems are connected through aphids and their parasitoids, whereas cereal agroecosystems represent a separate group of associations.