Costas Fasseas - Academia.edu (original) (raw)

Papers by Costas Fasseas

Journal of Plant Physiology, 2019

This study aimed to investigate the firmness retention by ethylene treatment in olive fruit, as o... more This study aimed to investigate the firmness retention by ethylene treatment in olive fruit, as observed earlier. Ethylene concentrations up to 1000 μL L-1 were applied to dark green 'Konservolia' olives harvested shortly before the green maturation and exposed to 20 °C for up to 9 d. Surprisingly, the results indicated a tendency to fruit firmness increases in concentration-dependent manner in a non-climacteric fruit. The highest concentration increased the firmness within 12 h by approximately 1.35-fold, but transiently for approximately up to 5 d; all ethylene inhibitors tested, either of synthesis (ethoxyvinyl glycine or AVG), or perception (1 -methyl-cyclopropene or 1-MCP, and silver nitrate) prevented the firmness increase. Texture was evaluated by firmness and changes in lignin, cellulose (CL), total pectins (TPC), water soluble pectins (WSP) and total non-cellulosic sugars (total sugars) concentrations, and in pectin esterification degree (DE) in the alcohol insoluble residue (AIR) of 'Konservolia' fruit pericarp during 1.5-d, 5-d and 10-d treatments with 1000 μL L-1 ethylene at 20 °C. Pectins in AIR were also extracted sequentially with cyclohexane-trans-1,2-diaminetetra-acetate (CDTA), Na2CO3, 1 M and 4 M KOH. The results showed that on day 1.5, the increased firmness was consistent with increased CL (crystalline formation, as observed by microscopy), total sugars and DE levels, but reduced WSP, whereas softening reversed the changes and lowered TPC and CDTA-soluble pectins in all fruit on day 10. However, on day 5 ethylene-treated olives exhibited a transitional phase during softening, characterized by retention of high TPC concentration and energy demand, as indicated by elevated respiration rates. The inhibitor 1-MCP, applied before ethylene, did inhibit the responses to ethylene treatment. Ethylene firming effect and the respective cell wall changes in olives are demonstrated for first time. The experiments could be used for research on perception and transcription responses to ethylene in olive, a non-climacteric fruit. In practice, high ethylene concentrations could also be beneficial for firmness increase and/or short storage of dark green olives.

The Journal of Horticultural Science and Biotechnology, 2006

ABSTRACT

Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Horticulture, 2015

Limoniastrum monopetalum L. is an interesting small shrub native to Greece and other Mediterranea... more Limoniastrum monopetalum L. is an interesting small shrub native to Greece and other Mediterranean countries with an attractive foliage, and blooming in the summer with pink flowers. In this work an anatomical and hystochemical study of the species were carried out in order to investigate the suitability of the L. monopetalum for use in urban and suburban areas as ornamental plant and its growth in hostile environments such as archeological sites, roof gardens, landscape restoration (e.g. quarries, roadsides, etc.). The results showed that the leaves of L. monopetalum are amphistomatic bifacial with leaf blade approx. 170 μm thick. The epidermal cells is relatively thick approximately 20 μm and covered by a 2 μm thick cuticle. Furthermore both surfaces of the leaves are entirely covered by salt crystals secreted by the salt glands, as this is revealed from fresh unprocessed specimens observed with the SEM.The histochemical tests showed the presence of terpenoids in the cell walls of the epidermal cells and in the leaf vascular tissues, phenolics, nitrites and alkaloids, flavonoids in the mesophyll cells, especially in the vacuoles, and lipids only in the cuticle. Both morphological anatomical and histochemical characteristics of the leaves indicate the xeromorphic character of the species which render L. monopetalum a suitable plant for ornamental use in a wide spectrum of areas with adverse conditions

Journal of General Virology, 1989

The distribution of parsnip yellow fleck virus particle antigen in infected cells of Nicotiana cl... more The distribution of parsnip yellow fleck virus particle antigen in infected cells of Nicotiana clevelandii or Spinacia oleracea was examined by immunogold labelling of ultrathin sections. Best results were obtained by pretreating sections with Decon 75 followed by long incubation times on antiserum (16 h) and gold probe (6 h). The cytoplasmic inclusions induced by infection have three main components: accumulations of 20 to 30 nm diameter tubules, granular bodies and amorphous matrix material. Much gold label was located over the areas of amorphous matrix material whereas the other components of the inclusions were not labelled. Specific but less dense labelling was observed over virus-induced cell wall outgrowths, and overother areas of cell wall and some nuclei in infected cells. Virus-like particles found in 45 nm diameter tubules within the cell wall outgrowths were not labelled, perhaps because they were inaccessible to the antibody. The results indicate that large amounts of virus particle antigen are present in cells. However, the number of recognizable virus particles was considerably less than expected from the amount of virus extracted from leaves.

Flora - Morphology, Distribution, Functional Ecology of Plants, 2010

The tube systems known to exist in tracheophytes are xylem, phloem and laticifers which are compo... more The tube systems known to exist in tracheophytes are xylem, phloem and laticifers which are composed of living or non-living cells and secretory ducts/canals and aerenchyma that is of schizogenous or lysigenous origin. Here, we describe a novel type of tube network of unknown function that ramifies through the olive tree bark and is composed of groups of apparently empty, anastomosing tubules interrupted by perforated plates; side openings of the tubules connect them to the intercellular spaces of the cortex.

Canadian Journal of Botany, 2007

Polymorphism with respect to size and structural characteristics occurs in pollen grains of sever... more Polymorphism with respect to size and structural characteristics occurs in pollen grains of several species. Pollen grains of Thymus capitatus (L.) Hoffmans & Link. from three different areas of Greece were collected, and their palynological characteristics were measured. Using light and scanning electron microscopy, a quantification of pollen polymorphism of T. capitatus was achieved by measuring the size and the characteristics of exine sculpture. The measurements were repeated during 3 successive years, and statistical analyses with one-way ANOVA and Duncan’s multiple range test were applied. Results revealed differences in the exine pattern between the locations; also, three palynological characteristics (surface, perimeter, and equatorial diameter) differed statistically. The results clearly indicate that pollen grains of T. capitatus are polymorphic between the sampling areas. The polymorphism has been related to environmental parameters and mainly with water availability. Ave...

Biosensors and Bioelectronics, 2004

The Bioelectric Recognition Assay (BERA) is a whole-cell based biosensing system that detects the... more The Bioelectric Recognition Assay (BERA) is a whole-cell based biosensing system that detects the electric response of cultured cells, suspended in a gel matrix, to various ligands, which bind to the cell and/or affect its physiology. Previous studies have demonstrated the potential application of this method for rapid, inexpensive detection of viruses in a crude sample. However, the understanding, so far, of the fundamental processes that take place during cell-virus interactions within the probe has been rather limited. In the present study, we combined electrophysiological and fluorescence microscopical assays, so that we can prove that animal and plant cells immobilized in BERA sensors respond to different viruses primarily by changing their membrane potential. The response of immobilized cells against different viruses did not depend on the virus ability to penetrate the cell, but was modified after binding each virus to a virus-specific antibody or removal of its coat protein after treatment with a protease. Consequently, we were able to assay the presence of a virus in its complete form or fragments thereof. Combination of immunological recognition with the electrophysiological response of immobilized cells allows for a considerable increase of the specificity of the BERA biosensory assay. In addition, rather than simply detect the presence of a protein or genomic sequence, the method can help gain information on the bioactivity of a virus.

Applied Microbiology and Biotechnology, 2012

This study examined the effects of three lactic acid bacteria (LAB) strains on the nematode Caeno... more This study examined the effects of three lactic acid bacteria (LAB) strains on the nematode Caenorhabditis elegans. Lactobacillus salivarius, Lactobacillus reuteri, and Pediococcus acidilactici were found to inhibit the development and growth of the worm. Compared to Escherichia coli used as the control, L. reuteri and P. acidilactici reduced the lifespan of wild-type and short-lived daf-16 worms. On the contrary, L. salivarius extended the lifespan of daf-16 worms when used live, but reduced it as UV-killed bacteria. The three LAB induced the expression of genes involved in pathogen response and inhibited the growth of tumor-like germ cells, without affecting DAF16 localization or increasing corpse cells. Our results suggest the possible use of C. elegans as a model for studying the antitumor attributes of LAB. The negative effects of these LAB strains on the nematode also indicate their potential use against parasitic nematodes.

Coexistence of shrubs and grass in a semi-arid landscape: a case study of mulga (Acacia aneura, M... more Coexistence of shrubs and grass in a semi-arid landscape: a case study of mulga (Acacia aneura, Mimosaceae) shrublands embedded in fire-prone spinifex (Triodia pungens, Poaceae) hummock grasslands.

Biochemical Systematics and Ecology, Dec 1, 2007

The chemical composition of the essential oil extracted from fresh leaves of Lippia citriodora (V... 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.

American Journal of Physiology-Cell Physiology

The development of resistance to hormone therapy caused by both fulvestrant and tamoxifen promote... 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.

Agrochimica

Agrochimica publishes in English original papers, reviews and short communications written by res... more Agrochimica publishes in English original papers, reviews and short communications written by researchers from all over the world and peer reviewed by referees familiar with the fields of research involved. The Journal focuses on plant and soil chemistry and biochemistry as well as on the chemical aspects of plant nutrition. Also covered are several new, rapidlyexpanding fields such as agricultural and environmental pollution, agro-industrial biotechnology, pesticides and agricultural waste treatment and disposal. The Journal places particular attention on all scientific aspects connected with the agricultural chemistry and the environment protection. Ethics Multiple reporting of research-Papers (or parts of them) should not be already published or under editorial consideration for publication elsewhere. Resubmission of a previously rejected manuscript is permitted following Editor's decision. Plagiarism-The Editor will not tolerate plagiarism.

Mitochondrial structure and function is emerging as a major contributor to neuromuscular disease,... 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 quantitie... 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...

Spanish Journal of Agricultural Research, 2019

Aim of study: To assess the role of polyphenol oxidase (PPO), peroxidase (POD) and indole-3-aceti... 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...

Journal of Experimental Botany, 2019

Under certain conditions, leaf cystoliths of Parietaria judaica can decompose, and the CO2 releas... more 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.

Journal of Plant Physiology, 2018

Boron (B) toxicity frequently affects plant performances and productivity, especially in arid and... more Boron (B) toxicity frequently affects plant performances and productivity, especially in arid and semi-arid environments. In this experiment, loquat seedlings were subjected to 25 μΜ (control) or 400 μΜ B (B excess) to test the hypothesis that (i) B alter sugar/polyol metabolism in polyol-producing tree species as loquat and (ii) changes of leaf and stem anatomy assist young tissues against toxic effect of B. Gas exchange parameters were monitored until 147 days from the beginning of the experiment (FBE), one week later the first visible symptoms of B toxicity appeared in the upper part of stems. At 147 FBE, plant biometric parameters and pattern of B accumulation, leaf and stem anatomy, chlorophyll a fluorescence kinetics as well as biochemical measurements were assessed in top (asymptomatic) leaves and upper stem bark. Boron accumulated principally (in the row) in top leaves > top bark > top wood in B-stressed plants, but no changes in allocation pattern were found between controls and B-stressed plants. Excess B promoted the increase in the spongy layer of top leaves and caused the development of cork and numerous collenchyma cells with increased cell wall thickness. This mechanism, which has never been described before, can be considered an attempt to store excessive B in tissues where B ions are less harmful. The accumulation of sorbitol (B-complexing polyol) in top leaves and stem bark can be considered as a further attempt to detoxify B excess. However, B toxicity drastically affects the photosynthetic rate of top leaves, mainly due to non-stomatal limitations, i.e., reduction of ambient CO2 use efficiency and of photosystem II (PSII) efficiency, modification of the partitioning excess energy dissipation in PSII, thus leading to an increased level of lipid peroxidation. Our results suggest that changes in sugar metabolism associated with leaf and stem bark thickening partially assist (but not totally preserve) young tissues of loquat plants under B stress.

Protoplasma, Jan 17, 2018

In many plant species, carbon-calcium inclusion (calcium oxalate crystals or cystoliths containin... 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...

Genes to Cells, 2017

Escherichia coli PpiB is a peptidyl-prolyl cis/trans isomerase (PPIase, EC: 5.2.1.8) with chapero... more Escherichia coli PpiB is a peptidyl-prolyl cis/trans isomerase (PPIase, EC: 5.2.1.8) with chaperone activity. Here, we show that the DppiB deletion strain and the PpiB over-expression wild-type strain are both characterized by defects in cell division involving milder or severe cell filamentation, respectively. Using various PpiB mutants, we show that the PPIase activity of PpiB is necessary for the observed cell filamentation, whereas other structural features apart from the active site are also important for this phenotype. Early divisome components zipA and ftsZ showed decreased expression in DppiB cells, whereas the corresponding proteins partially suppressed the division phenotype of DppiB cells as well. Although PpiB itself has no obvious specific affinity for the septal ring as a GFP translational fusion showed a diffuse cytoplasmic localization, it interacts with FtsZ employing the C-terminal FtsZ domain, decreases its GTPase activity and when over-expressed shows an inhibitory effect on the proper FtsZ localization at future division sites. Furthermore, additional putative PpiB prey proteins are able to partially restore the DppiB phenotype indicating that PpiB is able to control bacterial cell division by probably modulating the function of various other proteins which are indirectly associated with the process.