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PAPERS PUBLISHED IN INTERNATIONAL SCIENTIFIC JOURNALS DURING 2014

C. Chimona, A. Karioti, H. Skaltsa & S. Rhizopoulou (2014) Occurrence of secondary metabolites in tepals of Asphodelus ramosus L. Plant Biosystems, in press DOI:10.1080/11263504.2013.790851
 
Abstract: Major processes contributing to subtleties of ephemeral flowers of Asphodelus ramosus are related to chemical constituents detected in tepals which expand during cold and wet seasons in the eastern Mediterranean. Luteolin, caffeic acid, chlorogenic, and p-hydroxy-benzoic acids are the main constituents, whereas alkanes, ketones, and fatty acids appear in low amounts.
 
Anastasia Christopoulou, Nikolaos M. Fyllas, Pavlos Andriopoulos, Nikos Koutsias, Panayiotis G. Dimitrakopoulos, Margarita Arianoutsou (2014). Post-fire regeneration patterns of Pinus nigra in a recently burned area in Mount Taygetos, Southern Greece: The role of unburned forest patches. Forest Ecology and Management 327 (2014) 148–156 (http://dx.doi.org/10.1016/j.foreco.2014.05.006)
 
Abstract: Pinus nigra (black pine) is an ecologically and economically important species widely distributed around the Mediterranean Basin. P. nigra ecosystems have recently been affected by high severity fires occurring over the mountainous forest ecosystems of Southern Europe. The aim of this study is to investigate the post-fire regeneration patterns of black pine after a high severity crown fire which occurred on Mt Taygetos in Southern Greece. A network of 18 sites was selected to study black pine natural post-fire regeneration. Regeneration density was higher at the edges of patches that have remained unburned within the periphery of fire (0.406 individuals/m2) as compared to isolated burned areas (0.007 individuals/m2) although a significant between sites heterogeneity was recorded. Boosted regression trees analysis was used to explore the effects of environmental and microhabitat variables on black pine post-fire regeneration. The number of fires a site has experienced had a negative effect on regeneration density, while the presence of recovering ferns had a positive effect. The most important variable related to the black pine post-fire regeneration was distance from unburned patches. The result of the current study substantiates the importance of maintaining fire-resistant stands with large trees that are more likely to survive after a surface fire and which can also serve as seed sources for the recolonization of the burned area after severe crown fires.
 
Richard M. Cowling, Alastair J. Potts, Peter L. Bradshaw, Jonathan Colville, Margarita Arianoutsou, Simon Ferrier, Felix Forest, Nikolaos M. Fyllas, Stephen D. Hopper, Fernando Ojeda, Serban Proches, Rhian J. Smith, Philip W. Rundel, Emmanuel Vassilakis and Brian R. Zutta (2014) Variation in plant diversity in mediterranean-climate ecosystems: the role of climatic and topographical stability. Journal of Biogeography. doi:10.1111/jbi.12429
 
Abstract: Although all five of the major mediterranean-climate ecosystems (MCEs) of the world are recognized as loci of high plant species diversity and endemism, they show considerable variation in regional-scale richness. Here, we assess the role of stable Pleistocene climate and Cenozoic topography in explaining variation in regional richness of the globe’s MCEs. We hypothesize that older, more climatically stable MCEs would support more species, because they have had more time for species to accumulate than MCEs that were historically subject to greater topographic upheavals and fluctuating climates. We  estimated  plant  diversity  for  each  MCE  as  the  intercepts  of species–area curves that are homogeneous in slope across all regions. We used two down-scaled global circulation models of the Last Glacial Maximum (LGM) to quantify climate stability by comparing the change in the location of MCEs between the LGM and present. We quantified the Cenozoic topographic stability of each MCE by comparing contemporary topographic profiles with those present in the late Oligocene and the early Pliocene. Variation in plant diversity in MCEs is likely to be a consequence not of differences in diversification rates, but rather the persistence of numerous pre-Pliocene clades in the more stable MCEs.  The  extraordinary plant diversity of the Cape is a consequence of the combined effects of both mature and recent radiations, the latter associated with increased habitat heterogeneity produced by mild tectonic uplift in the Neogene.
 
Diallinas G. (2014) Understanding transporter specificity and the discrete appearance of channel-like gating domains in transporters. Front Pharmacol. 2014 Sep 12;5:207. doi: 10.3389/fphar.2014.00207
 
Abstract: Transporters are ubiquitous proteins mediating the translocation of solutes across cell membranes, a biological process involved in nutrition, signaling, neurotransmission, cell communication and drug uptake or efflux. Similarly to enzymes, most transporters have a single substrate binding-site and thus their activity follows Michaelis-Menten kinetics. Substrate binding elicits a series of structural changes, which produce a transporter conformer open toward the side opposite to the one from where the substrate was originally bound. This mechanism, involving alternate outward- and inward-facing transporter conformers, has gained significant support from structural, genetic, biochemical and biophysical approaches. Most transporters are specific for a given substrate or a group of substrates with similar chemical structure, but substrate specificity and/or affinity can vary dramatically, even among members of a transporter family that show high overall amino acid sequence and structural similarity. The current view is that transporter substrate affinity or specificity is determined by a small number of interactions a given solute can make within a specific binding site. However, genetic, biochemical and in silico modeling studies with the purine transporter UapA of the filamentous ascomycete Aspergillus nidulans have challenged this dogma. This review highlights results leading to a novel concept, stating that substrate specificity, but also transport kinetics and transporter turnover, are determined by subtle intramolecular interactions between a major substrate binding site and independent outward- or cytoplasmically-facing gating domains, analogous to those present in channels. This concept is supported by recent structural evidence from several, phylogenetically and functionally distinct transporter families. The significance of this concept is discussed in relationship to the role and potential exploitation of transporters in drug action.
 
Galanopoulou K., Scazzocchio C., Galinou M.E., Liu W., Borbolis F., Karachaliou M., Oestreicher N., Hatzinikolaou D.G., Diallinas G., Amillis S. (2014) Purine utilization proteins in the Eurotiales: Cellular compartmentalization, phylogenetic conservation and divergence. Fungal Genet Biol doi: 10.1016/j.fgb.2014.06.005
 
Abstract: The purine utilisation pathway has been thoroughly characterised in Aspergillus nidulans. We establish here the subcellular distribution of seven key intracellular enzymes, xanthine dehydrogenase (HxA), urate oxidase (UaZ), 5-hydroxy-isourate hydrolase (UaX), 2-oxo-4-hydroxy-4-carboxy ureido imidazoline decarboxylase (UaW), allantoinase (AlX), allantoicase (AaX), ureidoglycolate lyase (UglA), and the fungal-specific α-ketoglutarate Fe(II)-dependent dioxygenase(XanA). HxA, AlX, AaX, UaW and XanA are cytosolic, while UaZ, UaX and UglA are peroxisomal. Peroxisomal localization was confirmed by using appropriate pex mutants. The pathway is largely, but not completely conserved in the Eurotiomycetes, noticeably in some species AaX is substituted by an alternative enzyme of probable bacterial origin. UaZ and the urate-xanthine UapA and UapC transporters, are also localised in specific cells of the conidiophore. We show that metabolic accumulation of uric acid occurring in uaZ null mutations is associated with an increased frequency of appearance of morphologically distinct colony sectors, diminished conidiospore production, UV resistance and an altered response to oxidation stress, which may provide a rationale for the conidiophore-specific localisation. The pathway-specific transcription factor UaY is localized in both the cytoplasm and nuclei under non-inducing conditions, but it rapidly accumulates exclusively to the nuclei upon induction by uric acid
 
Panayiota Kotsakiozi, Aristeidis Parmakelis, Ioanna-Katerina Aggeli, Catherine Gaitanaki, Sinos Giokas, and Efstratios D. Valakos (2014) Water balance and expression of heat-shock protein 70 in codringtonia species: a study within a phylogenetic framework J. Mollus. Stud. doi:10.1093/mollus/eyu042
 
Abstract: Seasonal differences in the water content of four Codringtonia species were investigated using specimens collected from the field. In addition, rate of water loss and expression of heat-shock protein 70 (Hsp70) were measured in a laboratory setting with six Codringtonia species subjected to a short-term heat shock. Using a phylogenetic framework, both the Hsp70 expression levels and the rate of water loss were investigated for their correlation with spatial and climatic variables. As indicated by the field-collected samples, during summer aestivation only C. helenae exhibited a tendency for water loss. During the short-term heat shock the rate of water loss in C. helenae was also significantly greater. No interspecific differences could be detected in the levels of Hsp70 in the species subjected to short-term heat shock. A single Codringtonia species seemed to maintain increased Hsp70 protein levels. In the species subjected to short-term heat shock, a positive relationship was found between Hsp70 levels and rate of water loss. On the other hand, the Hsp70 levels under normal conditions showed a negative correlation with altitude and mean summer precipitation of the sampling localities. Thus, species seem to adapt to harsher environmental conditions by maintaining higher levels of Hsp70
 
Koutsomitrou D., Detsis V., Efthimiou G. & A. Economou-Amilli (2014) Water quality and condition of riverbanks of Kifisos River, Attica, Greece. Journal of International Scientific Publications: Ecology and Safety, Volume 8,ISSN 1314-7234 (Online), (http://www.scientific-publications.net)
 
Abstract: The aim of this study is to assess the condition of Kifisos River in Attica, Greece, with respect to water quality and riparian ecosystems status. Four representative sampling sites were examined. Water samples were collected in winter and spring 2013 and the following parameters were examined: water and air temperature, pH, conductivity, nitrate, nitrite and phosphate ion concentration, BOD5 and COD. The sites were sampled twice for macroinvertebrate fauna; specimens were identified to the appropriate level. The riparian ecosystems status was established based on the HMS index and HQA score of the RHS protocol. The results led to proposals for the holistic management of the Kifisos River ecosystem, as part of the urban landscape.
 
Koutsomitrou D., Efthimiou G., Detsis V. & A. Economou-Amilli (2014) Ecological assessment of Kifisos river channel and the riparian forest vegetation. ‘Water resources and wetlands’, Tulcea-Romania, ISSN: 2285-7923, pp: 87-93
 
Abstract: The objective of this study is to determine and evaluate the current condition of  Kifisos River in Attica (Greece) as far as the status of riparian forest ecosystems, phytosociology and habitat structure is concerned. Four (4) different sampling sites were examined, covering a representative section of the river: one near the springs, one at the estuary and two intermediate (non-boxed section) in the residential zone. The status of riparian forest ecosystems was investigated, according to the RHS protocol, and especially by means of the HMS index and HQA score. Concerning the RHS protocol, 10 spot-checks were surveyed and the following data were recorded: substrate of the channel, type of water flow, special characteristics of the channel, types of vegetation, use of the riverbank, complexity of vegetation structure of the bank and type of artificial modifications of the channel and the banks. The calibration system HQA (Habitat Quality Assessment) was used as a measure of diversity and ‘naturalness’ of each sampling site, including the channel and the 'river corridor', while the artificial change in the physical structure of the channel was expressed as the degree of modification of the habitat (Habitat Modification Score). Results have revealed strong modifications in the riparian vegetation and in the river corridor at the residential sites; mostly at the one that is located in the center of the city. The riparian vegetation was dominated by cosmopolitan species, resistant to pollution, a result of the impact of urban waste and polluted drainage that end up to the river ecosystem. The sites closer to the springs, have been subjected to less disturbance by human activities and, as the HQA score has indicated, can be suitable habitat of animal species, especially macroinvertebrates. The results mentioned above have led to proposals for the management of Kifisos River ecosystem in a holistic way, as part of the urban landscape.
 
Krypotou E., Diallinas G. (2014) Transport assays in filamentous fungi: Kinetic characterization of the UapC purine transporter of Aspergillus nidulans. Fungal Genet Biol 63C:1-8
 
Abstract: Transport assays allow the direct kinetic analysis of a specific transporter by measuring apparent Km and Vmax values, and permit the characterization of substrate specificity profiles through competition assays. In this protocol we describe a rapid and easy method for performing uptake assays in the model filamentous ascomycete Aspergillus nidulans. Our method makes use of A. nidulans germinating conidiospores at a defined morphological stage in which most transporters show maximal expression, avoiding technical difficulties associated with the use of mycelia. In combination with the ease of construction of genetic null mutants in A. nidulans, our method allows the rigorous characterization of any transporter in genetic backgrounds that are devoid of other transporters of similar specificity. Here, we use this method to characterize the kinetic parameters and the specificity profile of UapC, a uric acid-xanthine transporter present in all ascomycetes and member of the ubiquitous Nucleobase-Ascorbate Transporter family, in specific genetic backgrounds lacking other relevant transporters
 
Kyriakou, E., Chatzoglou, E., Zouros, E. and Rodakis, G. C. (2014) The rRNA and tRNA transcripts of maternally and paternally inherited mtDNAs of Mytilus galloprovincialis suggest presence of a ‘degradosome’ in mussel mitochondria and necessitate the re-annotation of the l-rRNA/CR boundary. Gene (in press).
 
Abstract: Species of the genus Mytilus carry two mitochondrial genomes in obligatory coexistence; one transmitted though the eggs (the F type) and one through the sperm (the M type). We have studied the 3΄ and 5΄ ends of rRNA and tRNA transcripts using RT-PCR and RNA circularization techniques in both the F and M genomes of Mytilus galloprovincialis. We have found polyadenylated and non-adenylated transcripts for both ribosomal and transfer RNAs. In all these genes the 5΄ ends of the transcripts coincided with the first nucleotide of the annotated genes, but the 3΄ ends were heterogeneous. The l-rRNA 3΄ end is 47 or 48 nucleotides upstream from the one assigned by a previous annotation, which makes the adjacent first domain (variable domain one, VD1) of the main control region (CR) correspondingly longer. We have observed s-rRNA and l-rRNA transcripts with truncated 3΄ end and polyadenylated tRNA transcripts carrying the CCA trinucleotide. We have also detected polyadenylated RNA remnants carrying the sequences of the control region, which strongly suggests RNA degradation activity and thus presence of degradosomes in Mytilus mitochondria.
 
Lagopati N, Tsilibary EP, Falaras P, Papazafiri P, Pavlatou EA, Kotsopoulou E, Kitsiou P. (2014) Effect of nanostructured TiO₂ crystal phase on photoinduced apoptosis of breast cancer epithelial cells. Int J Nanomedicine. 2014 Jul 3;9:3219-30. doi: 10.2147/IJN.S62972. eCollection 2014.
 
Abstract: PURPOSE: The use of nanoparticles has seen exponential growth in the area of health care, due to the unique physicochemical properties of nanomaterials that make them desirable for medical applications. The aim of this study was to examine the effects of crystal phase-nanostructured titanium dioxide particles on bioactivity/cytotoxicity in breast cancer epithelial cells. - MATERIALS AND METHODS: Cultured Michigan Cancer Foundation (MCF)-7 and human breast adenocarcinoma (MDA-MB-468) breast cancer epithelial cells were exposed to ultraviolet A light (wavelength 350 nm) for 20 minutes in the presence of aqueous dispersions of two different nanostructured titanium dioxide (TiO₂) crystal phases: anatase and an anatase-rutile mixture. Detailed characterization of each titanium dispersion was performed by dynamic light scattering. A 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) colorimetric assay was employed to estimate the percentage of viable cells after each treatment. Western blot analysis of protein expression and characterization, as well as a deoxyribonucleic acid (DNA)-laddering assay, were used to detect cell apoptosis. - RESULTS: Our results documented that 100% anatase TiO₂ nanoparticles (110-130 nm) exhibited significantly higher cytotoxicity in the highly malignant MDA-MB-468 cancer cells than anatase- rutile mixtures (75%/25%) with the same size. On the contrary, MCF-7 cells (characterized by low invasive properties) were not considerably affected. Exposure of MDA-MB-468 cells to pure anatase nanoparticles or anatase-rutile mixtures for 48 hours resulted in increased proapoptotic Bax expression, caspase-mediated poly(adenosine diphosphate ribose) polymerase (PARP) cleavage, DNA fragmentation, and programmed cell death/apoptosis. - CONCLUSION:The obtained results indicated that pure anatase TiO₂ nanoparticles exhibit superior cytotoxic effects compared to anatase-rutile mixtures of the same size. The molecular mechanism of TiO₂ nanoparticle cytotoxicity involved increased Bax expression and caspase-mediated PARP inactivation, thus resulting in DNA fragmentation and cell apoptosis.
 
Lamprinou V., Danielidis D.B., Pantazidou A., Oikonomou A. & A. Economou-Amilli (2014) The show cave of Diros vs. wild caves of Peloponnese, Greece - Distribution patterns of Cyanobacteria. International Journal of Speleology, 43(3): 335-342, Tampa, FL (USA)
 
Abstract: The karst cave ‘Vlychada’ of Diros, one of the oldest show caves in Peloponnese, sustains extended phototrophic biofilms on various substrata – on rocks inside the cave including speleothems, and especially near the artificial lighting installation (‘Lampenflora’). After asurvey of the main abiotic parameters (Photosynthetically Active Radiation -PAR, Temperature-T, Relative Humidity -RH, Carbon Dioxide -CO2) three clusters of sampling sites were revealed according to Principal Component Analysis (PCA): (i) the water gallery section predominately influenced by CO2, (ii) the dry passages influenced by RH and PAR, and (iii) the area by the cave exit at the dry section influenced by temperature. The collected samples from the watergallery section and the dry passages of the cave revealed a total of 43 taxa of Cyanobacteria,with the unicellular/colonial forms being the most abundant. The applied non-metric Multidimensional Scaling Ordination (nMDS) of the cumulative species composition showed aclear distinction between the water gallery section and the dry passages of the cave. Further comparison with previous data from other wild caves of Peloponnese (‘Kastria’, ‘Francthi’, and‘Selinitsa’) was conducted revealing a distinction between the show cave and the wild ones. Apart from the human impact on cave ecosystems – through aesthetic alteration (‘greening’) of cave decorations by the ‘Lampenflora’, and by the cleaning treatments and restoration projects on the speleothems – identification of the organisms constituting the ‘Lampenflora’ might provide taxonomically and ecologically significant taxa.
 
Livanos P., Galatis B., Apostolakos P. (2014) The interplay between ROS and tubulin cytoskeleton in plants. Plant Signaling and Behavior 9:e28069
 
Abstract: Plants have to deal with reactive oxygen species (ROS) production, since it could potentially cause severe damages to different cellular components. On the other hand, ROS functioning as important second messengers are implicated in various developmental processes and are transiently produced during biotic or abiotic stresses. Furthermore, the microtubules (MTs) play a primary role in plant development and appear as potent players in sensing stressful situations and in the subsequent cellular responses. Emerging evidence suggests that ROS affect MTs in multiple ways. The cellular redox status seems to be tightly coupled with MTs. ROS signals regulate the organization of tubulin cytoskeleton and induce tubulin modifications. This review aims at summarizing the signaling mechanisms and the key operators orchestrating the crosstalk between ROS and tubulin cytoskeleton in plant cells. The contribution of several molecules, including microtubule associated proteins, oxidases, kinases, phospholipases and transcription factors, is highlighted.
 
Ioannis Mitsopoulos, Giorgos Mallinis and Margarita Arianoutsou (2014). Wildfire Risk Assessment in a Typical Mediterranean Wildland–Urban Interface of Greece. Environmental Management. DOI 10.1007/s00267-014-0432-6
 
Abstract: The purpose of this study was to assess spatial wildfire risk in a typical Mediterranean wildland–urban interface (WUI) in Greece and the potential effect of three different burning condition scenarios on the following four major wildfire risk components: burn probability, conditional flame length, fire size, and source–sink ratio. We applied the Minimum Travel Time fire simulation algorithm using the FlamMap and ArcFuels tools to characterize the potential response of the wildfire risk to a range of different burning scenarios. We created site-specific fuel models of the study area by measuring the field fuel parameters in representative natural fuel complexes, and we determined the spatial extent of the different fuel types and residential structures in the study area using photointerpretation procedures of large scale natural color orthophotographs. The results included simulated spatially explicit fire risk components along with wildfire risk exposure analysis and the expected net value change. Statistical significance differences in simulation outputs between the scenarios were obtained using Tukey’s significance test. The results of this study provide valuable information for decision support systems for short-term predictions of wildfire risk potential and inform wildland fire management of typical WUI areas in Greece.
 
Krypotou E., Lambrinidis G., Evangelidis T., Mikros E., Diallinas G. (2014) Modelling, substrate docking and mutational analysis identify residues essential  for function and specificity of the major fungal purine transporter AzgA. Mol Microbiol 93:129-45
 
Abstract: The AzgA purine/H(+) symporter of Aspergillus nidulans is the founding member of a functionally and phylogenetically distinct transporter family present in fungi, bacteria and plants. Here a valid AzgA topological model is built based on the crystal structure of the Escherichia coli uracil transporter UraA, a member of the nucleobase-ascorbate transporter (NAT/NCS2) family. The model consists of 14 transmembrane, mostly α-helical, segments (TMSs) and cytoplasmic N- and C-tails.  A distinct compact core of 8 TMSs, made of two intertwined inverted repeats (TMSs 1-4 and 8-11), is topologically distinct from a flexible domain (TMSs 5-7 and 12-14). A putative substrate binding cavity is visible between the core and the gate domains. Substrate docking, molecular dynamics and mutational analysis identified several residues critical for purine binding and/or transport in TMS3, TMS8 and TMS10. Among these, Asn131 (TMS3), Asp339 (TMS8) and Glu394 (TMS10) are proposed to directly interact with substrates, while Asp342 (TMS8) might be involved in subsequent substrate translocation, through H(+) binding and symport. Thus, AzgA and other NAT transporters use topologically similar TMSs and amino acid residues for substrate binding and transport, which in turn implies that AzgA-like proteins constitute a distant subgroup of the ubiquitous NAT family.
 
Giorgos Mallinis, Nikos Koutsias, Margarita Arianoutsou (2014) Monitoring land use/land cover transformations from 1945 to 2007 in two peri-urban mountainous areas of Athens metropolitan area, Greece. Science of the Total Environment 490 (2014) 262–278 (http://dx.doi.org/10.1016/j.scitotenv.2014.04.129)
 
Abstract: The aims of this study were to map and analyze land use/land cover transitions and landscape changes in the Parnitha and Penteli mountains, which surround the Athens metropolitan area of Attica, Greece over a period of 62 years. In order to quantify the changes between land categories through time, we computed the transition matrices for three distinct periods (1945–1960, 1960–1996, and 1996–2007), on the basis of available aerial photographs used to create multi-temporal maps. We identified systematic and stationary transitions with multi-level intensity analysis. Forest areas in Parnitha remained the dominant class of land cover throughout the 62 years studied, while transitional woodlands and shrublands were the main classes involved in LULC transitions. Conversely, in Penteli, transitional woodlands, along with shrublands, dominated the study site. The annual rate of change was faster in the first and third time intervals, compared to the second (1960–1996) time interval, in both study areas. The category level analysis results indicated that in both sites annual crops avoided to gain while discontinuous urban fabric avoided to lose areas. At the transition level of analysis, similarities as well as distinct differences existed between the two areas. In both sites the gaining pattern of permanent crops with respect to annual crops and the gain of forest with respect to transitional woodland/shrublands were stationary across the three time intervals. Overall, we identified more systematic transitions and stationary processes in Penteli. We discussed these LULC changes and associated them with human interference (activity) and other major socio-economic developments that were simultaneously occurring in the area. The different patterns of change of the areas, despite their geographical proximity, throughout the period of analysis imply that site-specific studies are needed in order to comprehensively assess the driving forces and develop models of landscape transformation in Mediterranean areas.
 
Sophia Rhizopoulou (2014) “Portrayals” of long-lived Mediterranean plants linked to virtues. Plant Biosystems, http://dx.doi.org/10.1080/11263504.2014.980356
 
Abstract: The association of plants with moral principles of individuals is presented in a miscellaneous, Medieval Greek manuscript. Botanical traits of 14 plants grown in Mediterranean landscapes have been used to express and awaken morals in the Middle Ages. Nowadays, plants symbolically linked to virtues represent a global resource for research.
 
Sophia Rhizopoulou, Helen Pantazi (2014) Constraints on floral water status of successively blossoming Mediterranean plants under natural conditions. Acta Botanica Gallica, in press.
 
Abstract: The water relations of showy laminar floral tissues (petals and tepals) were studied in twenty Mediterranean plants successively blossoming under ambient conditions. The water and the osmotic potential of floral tissues decline according to the succession of the median day of flowering of the selected plant species. The highest (less negative) value of floral water potential (–0.32 MPa), among the examined species, was measured in petals of Anemone coronaria in March, and the lowest value (–1.25 MPa) in petals of Coridothymus capitatus in June. Low values of water potential of floral tissues coincided with constraints in declining values of osmotic potential, at the onset of the dry period in the Mediterranean region; this apparently resulted in a reduction of turgor of floral tissues of Mediterranean plants subjected to water shortage. The reduced osmotic potential was correlated with enhanced soluble sugar content of floral tissues, presumably contributing to the expansion and water status of flowers under water scarcity, by decreasing water requirements.
 
Sanguinetti M., Amillis S., Pandano S., Scazzocchio C., and Ramón A. (2014) Modelling and mutational analysis of Aspergillus nidulans UreA, a member of the subfamily of urea/H+  transporters in fungi and plants. Open Biol 4:140070.
 
Abstract: We present the first account of the structure–function relationships of a protein of the subfamily of urea/H+ membrane transporters of fungi and plants, using Aspergillus nidulans UreA as a study model. Based on the crystal structures of the Vibrio parahaemolyticus sodium/galactose symporter (vSGLT) and of the Nucleobase-Cation-Symport-1 benzylhydantoin transporter from Microbacterium liquefaciens (Mhp1), we constructed a three-dimensional model of UreA which, combined with site-directed and classical random mutagenesis, led to the identification of amino acids important for UreA function. Our approach allowed us to suggest roles for these residues in the binding, recognition and translocation of urea, and in the sorting of UreA to the membrane. Residues W82, Y106, A110, T133, N275, D286, Y388, Y437 and S446, located in transmembrane helixes 2, 3, 7 and 11, were found to be involved in the binding, recognition and/or translocation of urea and the sorting of UreA to the membrane. Y106, A110, T133 and Y437 seem to play a role in substrate selectivity, while S446 is necessary for proper sorting of UreA to the membrane. Other amino acids identified by random classical mutagenesis (G99, R141, A163, G168 and P639) may be important for the basic transporter's structure, its proper folding or its correct traffic to the membrane.
 
Kostas Sagonas, Panayiotis Pafilis, Petros Lymberakis, Colin M. Donihue, Anthony Herrel and Efstratios D. Valakos (2014). Insularity affects head morphology, bite force and diet in a Mediterranean lizard. Biological Journal of the Linnean Society, 2014, 112, 469–484. 
 
Abstract: Island environments differ with regard to numerous features from the mainland and may induce large-scale changes in most aspects of the biology of an organism. In this study, we explore the effect of insularity on the morphology and performance of the feeding apparatus, a system crucial for the survival of organisms. To this end, we examined the head morphology and feeding ecology of island and mainland populations of the Balkan green lizard, Lacerta trilineata. We predicted that head morphology, performance and diet composition would differ between sexes and habitats as a result of varying sexual and natural selection pressures. We employed geometric morphometrics to test for differences in head morphology, measured bite forces and analysed the diet of 154 adult lizards. Morphological analyses revealed significant differences between sexes and also between mainland and island populations. Relative to females, males had larger heads, a stronger bite and consumed harder prey than females. Moreover, island lizards differed in head shape, but not in head size, and, in the case of males, demonstrated a higher bite force. Islanders had a wider food niche breadth and included more plant material in their diet. Our findings suggest that insularity influences feeding ecology and, through selection on bite force, head morphology.
 
Kostas Sagonas, Nikos Poulakakis, Petros Lymberakis, Aristeidis Parmakelis, Panayiotis Pafilis, Efstratios D. Valakos (2014). Molecular systematics and historical biogeography of the green lizards (Lacerta) in Greece: insights from mitochondrial and nuclear DNA. Molecular Phylogenetics and Evolution 76: 144-154
 
Abstract: The green lizards of the genus Lacerta (Sauria, Lacertidae) comprise nine recognized species, which in Europe are mainly restricted to the southern peninsulas. Four of them (L. trilineata, L. viridis, L. bilineata and L. agilis) occur in Greece. The uncertainty of morphological diversification renders the taxonomic assignment into species and subspecies problematic. In this study sequence data derived from two mitochondrial (cytochrome b and 16S rRNA) genes and one nuclear (NKTR) gene were used to (a) evaluate the taxonomic status of the genus Lacerta in Greece with emphasis on L. trilineata group and (b) investigate the evolutionary history of the genus through the application of phylogenetic and phylogeographic analyses, using Gallotia and Timon as outgroups. The phylogenetic analyses revealed the existence of four major clades. The first clade corresponds to L. trilineata group, the second to L. media, the third to L. agilis and the fourth to a complex of L. viridis and L. bilineata. However, the produced phylogenetic relationships are not congruent with the current taxonomy, especially in the first clade in which L. trilineata appeared to be paraphyletic in regard to L. pamphylica. Six distinct lineages were inferred within L. trilineata, despite the current recognition of nine morphological subspecies, the genetic differentiation of which exceeds that of other Lacerta species, imposing a thorough taxonomic revision of the species. Our results suggested a rapid diversification of L. trilineata group during the late Miocene. We believe that the present distribution of the genus in Greece is the result of several dispersal and vicariant events that took place during the late Miocene and early Pliocene.
 
Dimitrios Sarris, Anastasia Christopoulou, Eleni Angelonidi, Nikos Koutsias,  Peter Z. Fulé and Margarita Arianoutsou (2014) Increasing extremes of heat and drought associated with recent severe wildfires in southern Greece. Regional  Environmental Change 14:1257–1268.
 
Abstract: Mountains of the northern Mediterranean basin face two major threats under global change. Aridity and available fuel are both expected to increase because of climatic and land-use changes, increasing fire danger. There may already be signs of such effects in the case of the Pinus nigra and Abies cephalonica forests on Mt. Taygetos (southern Greece). We reconstructed climate (mid- to late-fire-season drought) using tree-rings for the last 150 years and compared it with the mountain’s fire history reconstructed from P. nigra fire scars. Seven, out of the ten, large fires Mt. Taygetos experienced were associated with below-normal precipitation (P) or above-normal maximum temperature (Tmax). The largest fires occurred in late summer of 1879, 1944, 1998, and 2007. However, only the recent fires (1998 and 2007) had both low P and high Tmax, also confirmed from long-term meteorological data. The synergy between climate and fuel availability may explain the very high intensity of 1998 and 2007 fires that burned mostly as stand-replacing crown fires. The other two large fire events (1879 and 1944) most likely occurred under reduced availability in burning fuel and were related to above-normal Tmax. Our findings are among the first based on long-term and site-specific empirical data to support the prediction that Mediterranean mountainous areas will face a very large threat from wildfires in the twenty-first century, if socioeconomic changes leading to land abandonment and thus burning fuel accumulation are combined with the drought intensification projected for the region under global warming.
 
Szalókia G, Pantzoua A, Prousis KC, Mavrofrydi O, Papazafiri P and  Calogeropoulou T. (2014) Design and synthesis of 21-alkynylaryl pregnenolone derivatives and evaluation of their anticancer activity. under revision
 
Abstract: A series of novel C21-alkynylaryl derivatives of pregnenolone were synthesized and screened for anticancer activity against a panel of three human cancer cell lines (LNCaP, A549 and MCF7). The data revealed that these compounds can be potential antitumour agents against the specific cell models. Compound 6f bearing a 2-trifluoromethylphenyl group was the most potent against all three cell lines.
 
Tsaousis G.N., Bagos P.G., Hamodrakas S.J. (2014)  HMMpTM: Improving transmembrane protein topology prediction using phosphorylation and glycosylation site prediction. Biochim. Biophys. Acta, 1844(2), 316 - 322,   doi: 10.1016/j.bbapap.2013.11. 001
 
Abstract: During the last two decades a large number of computational methods have been developed for predicting transmembrane protein topology. Current predictors rely on topogenic signals in the protein sequence, such as the distribution of positively charged residues in extra-membrane loops and the existence of N-terminal signals. However, phosphorylation and glycosylation are post-translational modifications (PTMs) that occur in a compartment-specific manner and therefore the presence of a phosphorylation or glycosylation site in a transmembrane protein provides topological information. We examine the combination of phosphorylation and glycosylation site prediction with transmembrane protein topology prediction. We report the development of a Hidden Markov Model based method, capable of predicting the topology of transmembrane proteins and the existence of kinase specific phosphorylation and N/O-linked glycosylation sites along the protein sequence. Our method integrates a novel feature in transmembrane protein topology prediction, which results in improved performance for topology prediction and reliable prediction of phosphorylation and glycosylation sites. The method is freely available at http://bioinformatics.biol.uoa.gr/HMMpTM
 
Tsiamis K., Panayotidis P., Economou-Amilli A. & Ch. Katsaros (2014) Seaweeds of the Greek coasts. II. Ulvophyceae. Mediterranean Marine Science, 15/…./ http://www.medit-mar-sc.net, Doi: dx.doi.org 10.12681/mms.574.
 
Abstract: An updated checklist of the green seaweeds (Ulvophyceae) of the Greek coasts is provided, based on both literature records and new collections. The total number of species and infraspecific taxa currently accepted is 96. The occurrence of each taxon in the North Aegean, South Aegean and Ionian Seas is given. In addition, 11 taxa pending confirmation of their presence, 9 excludenda and 15 inquirenda are briefly discussed.
 

 

The karst cave ‘Vlychada’ of Diros, one of the oldest show caves in Peloponnese, sustains extended phototrophic biofilms on various substrata – on rocks inside the cave including speleothems, and especially near the artificial lighting installation (‘Lampenflora’). After asurvey of the main abiotic parameters (Photosynthetically Active Radiation -PAR, Temperature-T, Relative Humidity -RH, Carbon Dioxide -CO2) three clusters of sampling sites were revealed according to Principal Component Analysis (PCA): (i) the water gallery section predominately

influenced by CO2, (ii) the dry passages influenced by RH and PAR, and (iii) the area by the cave exit at the dry section influenced by temperature. The collected samples from the watergallery section and the dry passages of the cave revealed a total of 43 taxa of Cyanobacteria,with the unicellular/colonial forms being the most abundant. The applied non-metric Multidimensional Scaling Ordination (nMDS) of the cumulative species composition showed aclear distinction between the water gallery section and the dry passages of the cave. Further comparison with previous data from other wild caves of Peloponnese (‘Kastria’, ‘Francthi’, and‘Selinitsa’) was conducted revealing a distinction between the show cave and the wild ones. Apart from the human impact on cave ecosystems – through aesthetic alteration (‘greening’) of cave decorations by the ‘Lampenflora’, and by the cleaning treatments and restoration projects on the speleothems – identification of the organisms constituting the ‘Lampenflora’ might provide taxonomically and ecologically significant taxa.