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A total of 461 indigenous Streptomycetes strains recovered from various Greek rhizosphere habitats were tested for their bioactivity. All isolates were examined for their ability to suppress the growth of 12 specific target microorganisms. Twenty-six were found to exert antimicrobial activity and were screened for potential nematicidal action. S. monomycini ATHUBA 220, S. colombiensis ATHUBA 438, S. colombiensis ATHUBA 431, and S. youssoufensis ATHUBA 546 were proved to have a nematicidal effect and thus were further sequenced. Batch culture supernatants and solvent extracts were assessed for paralysis on Meloidogyne javanica and Meloidogyne incognita second-stage juveniles (J2). The solvent extracts of S. monomycini ATHUBA 220 and S. colombiensis ATHUBA 438 had the highest paralysis rates, so these Streptomycetes strains were further on tested for nematodes’ biological cycle arrest on two Arabidopsis thaliana plants; the wild type (Col-0) and the katanin mutant fra2, which is susceptible to M. incognita. Interestingly, S. monomycini ATHUBA 220 and S. colombiensis ATHUBA 438 were able to negatively affect the M. incognita biological cycle in Col-0 and fra2 respectively, and increased growth in Col-0 upon M. incognita infection. However, they were ineffective against M. javanica. Fra2 plants were also proved susceptible to M. javanica infestation, with a reduced growth upon treatments with the Streptomyces strains. The nematicidal action and the plant-growth modulating abilities of the selected Streptomycetes strains are discussed.
Christianna Meidani; Alexandros Savvidis; Evaggelia Lampropoulou; Aggeliki Sagia; Efstathios Katsifas; Nikolaos Monokrousos; Dimitris G. Hatzinikolaou; Amalia D. Karagouni; Eleni Giannoutsou; Ioannis-Dimosthenis S. Adamakis; Nikoletta G. Ntalli. Τhe Nematicidal Potential of Bioactive Streptomyces Strains Isolated from Greek Rhizosphere Soils Tested on Arabidopsis Plants of Varying Susceptibility to Meloidogyne spp. Plants 2020, 9, 699 .
AMA StyleChristianna Meidani, Alexandros Savvidis, Evaggelia Lampropoulou, Aggeliki Sagia, Efstathios Katsifas, Nikolaos Monokrousos, Dimitris G. Hatzinikolaou, Amalia D. Karagouni, Eleni Giannoutsou, Ioannis-Dimosthenis S. Adamakis, Nikoletta G. Ntalli. Τhe Nematicidal Potential of Bioactive Streptomyces Strains Isolated from Greek Rhizosphere Soils Tested on Arabidopsis Plants of Varying Susceptibility to Meloidogyne spp. Plants. 2020; 9 (6):699.
Chicago/Turabian StyleChristianna Meidani; Alexandros Savvidis; Evaggelia Lampropoulou; Aggeliki Sagia; Efstathios Katsifas; Nikolaos Monokrousos; Dimitris G. Hatzinikolaou; Amalia D. Karagouni; Eleni Giannoutsou; Ioannis-Dimosthenis S. Adamakis; Nikoletta G. Ntalli. 2020. "Τhe Nematicidal Potential of Bioactive Streptomyces Strains Isolated from Greek Rhizosphere Soils Tested on Arabidopsis Plants of Varying Susceptibility to Meloidogyne spp." Plants 9, no. 6: 699.
The distribution of highly de-esterified homogalacturonans (HGs) in dividing protodermal cells of the monocotyledon Zea mays, the dicotyledon Vigna sinensis, and the fern Asplenium nidus was investigated in order to examine whether the cell wall region adjoining the preprophase band (PPB) is locally diversified. Application of immunofluorescence revealed that de-esterified HGs were accumulated selectively in the cell wall adjacent to the PPB in: (a) symmetrically dividing cells of stomatal rows of Z. mays, (b) the asymmetrically dividing protodermal cells of Z. mays, (c) the symmetrically dividing guard cell mother cells (GMCs) of Z. mays and V. sinensis, and (d) the symmetrically dividing protodermal cells of A. nidus. A common feature of the above cell types is that the cell division plane is defined by extrinsic cues. The presented data suggest that the PPB cortical zone-plasmalemma and the adjacent cell wall region function in a coordinated fashion in the determination/accomplishment of the cell division plane, behaving as a continuum. The de-esterified HGs, among other possible functions, might be involved in the perception and the transduction of the extrinsic cues determining cell division plane in the examined cells.
Eleni Giannoutsou; Basil Galatis; Panagiotis Apostolakos. De-Esterified Homogalacturonan Enrichment of the Cell Wall Region Adjoining the Preprophase Cortical Cytoplasmic Zone in Some Protodermal Cell Types of Three Land Plants. International Journal of Molecular Sciences 2019, 21, 81 .
AMA StyleEleni Giannoutsou, Basil Galatis, Panagiotis Apostolakos. De-Esterified Homogalacturonan Enrichment of the Cell Wall Region Adjoining the Preprophase Cortical Cytoplasmic Zone in Some Protodermal Cell Types of Three Land Plants. International Journal of Molecular Sciences. 2019; 21 (1):81.
Chicago/Turabian StyleEleni Giannoutsou; Basil Galatis; Panagiotis Apostolakos. 2019. "De-Esterified Homogalacturonan Enrichment of the Cell Wall Region Adjoining the Preprophase Cortical Cytoplasmic Zone in Some Protodermal Cell Types of Three Land Plants." International Journal of Molecular Sciences 21, no. 1: 81.
Meloidogyne incognita is a root knot nematode (RKN) species which is among the most notoriously unmanageable crop pests with a wide host range. It inhabits plants and induces unique feeding site structures within host roots, known as giant cells (GCs). The cell walls of the GCs undergo the process of both thickening and loosening to allow expansion and finally support nutrient uptake by the nematode. In this study, a comparative in situ analysis of cell wall polysaccharides in the GCs of wild-type Col-0 and the microtubule-defective fra2 katanin mutant, both infected with M. incognita has been carried out. The fra2 mutant had an increased infection rate. Moreover, fra2 roots exhibited a differential pectin and hemicellulose distribution when compared to Col-0 probably mirroring the fra2 root developmental defects. Features of fra2 GC walls include the presence of high-esterified pectic homogalacturonan and pectic arabinan, possibly to compensate for the reduced levels of callose, which was omnipresent in GCs of Col-0. Katanin severing of microtubules seems important in plant defense against M. incognita, with the nematode, however, to be nonchalant about this “katanin deficiency” and eventually induce the necessary GC cell wall modifications to establish a feeding site.
Christianna Meidani; Nikoletta G. Ntalli; Eleni Giannoutsou; Ioannis-Dimosthenis S. Adamakis. Cell Wall Modifications in Giant Cells Induced by the Plant Parasitic Nematode Meloidogyne incognita in Wild-Type (Col-0) and the fra2 Arabidopsis thaliana Katanin Mutant. International Journal of Molecular Sciences 2019, 20, 5465 .
AMA StyleChristianna Meidani, Nikoletta G. Ntalli, Eleni Giannoutsou, Ioannis-Dimosthenis S. Adamakis. Cell Wall Modifications in Giant Cells Induced by the Plant Parasitic Nematode Meloidogyne incognita in Wild-Type (Col-0) and the fra2 Arabidopsis thaliana Katanin Mutant. International Journal of Molecular Sciences. 2019; 20 (21):5465.
Chicago/Turabian StyleChristianna Meidani; Nikoletta G. Ntalli; Eleni Giannoutsou; Ioannis-Dimosthenis S. Adamakis. 2019. "Cell Wall Modifications in Giant Cells Induced by the Plant Parasitic Nematode Meloidogyne incognita in Wild-Type (Col-0) and the fra2 Arabidopsis thaliana Katanin Mutant." International Journal of Molecular Sciences 20, no. 21: 5465.
This article deals with the distribution of callose and of the homogalacturonan (HG) epitopes recognized by LM20, JIM5, and 2F4 antibodies in cell walls of differentiating and functioning stomatal complexes of the monocotyledon Zea mays and the dicotyledon Vigna sinensis. The findings revealed that, during stomatal development, in these plant species, callose appears in an accurately spatially and timely controlled manner in cell walls of the guard cells (GCs). In functioning stomata of both plants, callose constitutes a dominant cell wall matrix material of the polar ventral cell wall ends and of the local GC cell wall thickenings. In Zea mays, the LM20, JIM5, or 2F4 antibody-recognized HG epitopes were mainly located in the expanding cell wall regions of the stomatal complexes, while in Vigna sinensis, they were deposited in the local cell wall thickenings of the GCs as well as at the ledges of the stomatal pore. Consideration of the presented data favors the view that in the stomatal complexes of the monocotyledon Z. mays and the dicotyledon V. sinensis, the esterified HGs contribute to the cell wall expansion taking place during GC morphogenesis and the opening of the stomatal pore. Besides, callose and the highly de-esterified HGs allow to GC cell wall regions to withstand the mechanical stresses exerted during stomatal function.
Eleni Giannoutsou; P. Sotiriou; T. L. Nikolakopoulou; B. Galatis; P. Apostolakos. Callose and homogalacturonan epitope distribution in stomatal complexes of Zea mays and Vigna sinensis. Protoplasma 2019, 257, 141 -156.
AMA StyleEleni Giannoutsou, P. Sotiriou, T. L. Nikolakopoulou, B. Galatis, P. Apostolakos. Callose and homogalacturonan epitope distribution in stomatal complexes of Zea mays and Vigna sinensis. Protoplasma. 2019; 257 (1):141-156.
Chicago/Turabian StyleEleni Giannoutsou; P. Sotiriou; T. L. Nikolakopoulou; B. Galatis; P. Apostolakos. 2019. "Callose and homogalacturonan epitope distribution in stomatal complexes of Zea mays and Vigna sinensis." Protoplasma 257, no. 1: 141-156.
The challenge in today's bioaerosol monitoring is to retrieve real-time information on the qualitative and quantitative composition of the ambient air in bioparticles implicated to human health. A pilot study was conducted during March–May 2018 in Athens, Greece in order to detect bioparticles within the Planetary Boundary Layer (PBL) by implementing the LIF LiDAR (Laser-Induced Fluorescence Light Detection and Ranging) technique at an excitation wavelength of 266 nm in order to determine the major components' contribution on the total fluorescence LiDAR signals aloft (30–100 m above our site). The laboratory characterization of the prevalent pollen grains and fungal spores fluorescence signatures enabled through deconvolution the breaking down of the retrieved LIF LiDAR signals and unravelled each bioparticle's contribution. The bioaerosol occurrence and concentration, as determined by the concurrent sampling with a volumetric particle sampler, verified that the detected fluorescence is related to the fungal and pollen aerosol concentration. The results of this study are very promising for the implementation of remote sensing technology in routine detection and quantification of airborne bioparticles in real-time which is important for allergy sufferers and physicians.
S.C. Richardson; M. Mytilinaios; R. Foskinis; C. Kyrou; A. Papayannis; I. Pyrri; E. Giannoutsou; I.D.S. Adamakis. Bioaerosol detection over Athens, Greece using the laser induced fluorescence technique. Science of The Total Environment 2019, 696, 133906 .
AMA StyleS.C. Richardson, M. Mytilinaios, R. Foskinis, C. Kyrou, A. Papayannis, I. Pyrri, E. Giannoutsou, I.D.S. Adamakis. Bioaerosol detection over Athens, Greece using the laser induced fluorescence technique. Science of The Total Environment. 2019; 696 ():133906.
Chicago/Turabian StyleS.C. Richardson; M. Mytilinaios; R. Foskinis; C. Kyrou; A. Papayannis; I. Pyrri; E. Giannoutsou; I.D.S. Adamakis. 2019. "Bioaerosol detection over Athens, Greece using the laser induced fluorescence technique." Science of The Total Environment 696, no. : 133906.
BackgroundFormation of stomatal complexes in Poaceae is the outcome of three asymmetric and one symmetric cell division occurring in particular leaf protodermal cells. In this definite sequence of cell division events, the generation of subsidiary cells is of particular importance and constitutes an attractive model for studying local intercellular stimulation. In brief, an induction stimulus emitted by the guard cell mother cells (GMCs) triggers a series of polarization events in their laterally adjacent protodermal cells. This signal determines the fate of the latter cells, forcing them to divide asymmetrically and become committed to subsidiary cell mother cells (SMCs).ScopeThis article summarizes old and recent structural and molecular data mostly derived from Zea mays, focusing on the interplay between GMCs and SMCs, and on the unique polarization sequence occurring in both cell types. Recent evidence suggests that auxin operates as an inducer of SMC polarization/asymmetric division. The intercellular auxin transport is facilitated by the distribution of a specific transmembrane auxin carrier and requires reactive oxygen species (ROS). Interestingly, the local differentiation of the common cell wall between SMCs and GMCs is one of the earliest features of SMC polarization. Leucine-rich repeat receptor-like kinases, Rho-like plant GTPases as well as the SCAR/WAVE regulatory complex also participate in the perception of the morphogenetic stimulus and have been implicated in certain polarization events in SMCs. Moreover, the transduction of the auxin signal and its function are assisted by phosphatidylinositol-3-kinase and the products of the catalytic activity of phospholipases C and D.ConclusionIn the present review, the possible role(s) of each of the components in SMC polarization and asymmetric division are discussed, and an overall perspective on the mechanisms beyond these phenomena is provided.
P Apostolakos; Pantelis Livanos; Eleni Giannoutsou; Emmanuel Panteris; B Galatis. The intracellular and intercellular cross-talk during subsidiary cell formation in Zea mays: existing and novel components orchestrating cell polarization and asymmetric division. Annals of Botany 2018, 122, 679 -696.
AMA StyleP Apostolakos, Pantelis Livanos, Eleni Giannoutsou, Emmanuel Panteris, B Galatis. The intracellular and intercellular cross-talk during subsidiary cell formation in Zea mays: existing and novel components orchestrating cell polarization and asymmetric division. Annals of Botany. 2018; 122 (5):679-696.
Chicago/Turabian StyleP Apostolakos; Pantelis Livanos; Eleni Giannoutsou; Emmanuel Panteris; B Galatis. 2018. "The intracellular and intercellular cross-talk during subsidiary cell formation in Zea mays: existing and novel components orchestrating cell polarization and asymmetric division." Annals of Botany 122, no. 5: 679-696.
The distribution of homogalacturonans (HGAs) displaying different degrees of esterification as well as of callose was examined in cell walls of mature pavement cells in two angiosperm and two fern species. We investigated whether local cell wall matrix differentiation may enable pavement cells to respond to mechanical tension forces by transiently altering their shape. HGA epitopes, identified with 2F4, JIM5 and JIM7 antibodies, and callose were immunolocalised in hand‐made or semithin leaf sections. Callose was also stained with aniline blue. The structure of pavement cells was studied with light and transmission electron microscopy (TEM). In all species examined, pavement cells displayed wavy anticlinal cell walls, but the waviness pattern differed between angiosperms and ferns. The angiosperm pavement cells were tightly interconnected throughout their whole depth, while in ferns they were interconnected only close to the external periclinal cell wall and intercellular spaces were developed between them close to the mesophyll. Although the HGA epitopes examined were located along the whole cell wall surface, the 2F4‐ and JIM5‐ epitopes were especially localised at cell lobe tips. In fern pavement cells, the contact sites were impregnated with callose and JIM5‐HGA epitopes. When tension forces were applied on leaf regions, the pavement cells elongated along the stretching axis, due to a decrease in waviness of anticlinal cell walls. After removal of tension forces, the original cell shape was resumed. The presented data support that HGA epitopes make the anticlinal pavement cell walls flexible, in order to reversibly alter their shape. Furthermore, callose seems to offer stability to cell contacts between pavement cells, as already suggested in photosynthetic mesophyll cells.
P. Sotiriou; Eleni Giannoutsou; E. Panteris; B. Galatis; P. Apostolakos. Local differentiation of cell wall matrix polysaccharides in sinuous pavement cells: its possible involvement in the flexibility of cell shape. Plant Biology 2017, 20, 223 -237.
AMA StyleP. Sotiriou, Eleni Giannoutsou, E. Panteris, B. Galatis, P. Apostolakos. Local differentiation of cell wall matrix polysaccharides in sinuous pavement cells: its possible involvement in the flexibility of cell shape. Plant Biology. 2017; 20 (2):223-237.
Chicago/Turabian StyleP. Sotiriou; Eleni Giannoutsou; E. Panteris; B. Galatis; P. Apostolakos. 2017. "Local differentiation of cell wall matrix polysaccharides in sinuous pavement cells: its possible involvement in the flexibility of cell shape." Plant Biology 20, no. 2: 223-237.
The matrix cell wall materials, in developing Zea mays stomatal complexes are asymmetrically distributed, a phenomenon appearing related to the local cell wall expansion and deformation, the establishment of cell polarity, and determination of the cell division plane. In cells of developing Zea mays stomatal complexes, definite cell wall regions expand determinately and become locally deformed. This differential cell wall behavior is obvious in the guard cell mother cells (GMCs) and the subsidiary cell mother cells (SMCs) that locally protrude towards the adjacent GMCs. The latter, emitting a morphogenetic stimulus, induce polarization/asymmetrical division in SMCs. Examination of immunolabeled specimens revealed that homogalacturonans (HGAs) with a high degree of de-esterification (2F4- and JIM5-HGA epitopes) and arabinogalactan proteins are selectively distributed in the extending and deformed cell wall regions, while their margins are enriched with rhamnogalacturonans (RGAs) containing highly branched arabinans (LM6-RGA epitope). In SMCs, the local cell wall matrix differentiation constitutes the first structural event, indicating the establishment of cell polarity. Moreover, in the premitotic GMCs and SMCs, non-esterified HGAs (2F4-HGA epitope) are preferentially localized in the cell wall areas outlining the cytoplasm where the preprophase band is formed. In these areas, the forthcoming cell plate fuses with the parent cell walls. These data suggest that the described heterogeneity in matrix cell wall materials is probably involved in: (a) local cell wall expansion and deformation, (b) the transduction of the inductive GMC stimulus, and
Eleni Giannoutsou; P. Apostolakos; B. Galatis. Spatio-temporal diversification of the cell wall matrix materials in the developing stomatal complexes of Zea mays. Planta 2016, 244, 1125 -1143.
AMA StyleEleni Giannoutsou, P. Apostolakos, B. Galatis. Spatio-temporal diversification of the cell wall matrix materials in the developing stomatal complexes of Zea mays. Planta. 2016; 244 (5):1125-1143.
Chicago/Turabian StyleEleni Giannoutsou; P. Apostolakos; B. Galatis. 2016. "Spatio-temporal diversification of the cell wall matrix materials in the developing stomatal complexes of Zea mays." Planta 244, no. 5: 1125-1143.
Background and aims This work investigates the involvement of local differentiation of cell wall matrix polysaccharides and the role of microtubules in the morphogenesis of mesophyll cells (MCs) of three types (lobed, branched and palisade) in the dicotyledon Vigna sinensis and the fern Asplenium nidus.
P. Sotiriou; Eleni Giannoutsou; E. Panteris; P. Apostolakos; B. Galatis. Cell wall matrix polysaccharide distribution and cortical microtubule organization: two factors controlling mesophyll cell morphogenesis in land plants. Annals of Botany 2016, 117, 401 -419.
AMA StyleP. Sotiriou, Eleni Giannoutsou, E. Panteris, P. Apostolakos, B. Galatis. Cell wall matrix polysaccharide distribution and cortical microtubule organization: two factors controlling mesophyll cell morphogenesis in land plants. Annals of Botany. 2016; 117 (3):401-419.
Chicago/Turabian StyleP. Sotiriou; Eleni Giannoutsou; E. Panteris; P. Apostolakos; B. Galatis. 2016. "Cell wall matrix polysaccharide distribution and cortical microtubule organization: two factors controlling mesophyll cell morphogenesis in land plants." Annals of Botany 117, no. 3: 401-419.
The data presented in this work revealed that in Zea mays the exogenously added auxins indole-3-acetic acid (IAA) and 1-napthaleneacetic acid (NAA), promoted the establishment of subsidiary cell mother cell (SMC) polarity and the subsequent subsidiary cell formation, while treatment with auxin transport inhibitors 2,3,5-triiodobenzoic acid (TIBA) and 1-napthoxyacetic acid (NOA) specifically blocked SMC polarization and asymmetrical division. Furthermore, in young guard cell mother cells (GMCs) the PIN1 auxin efflux carriers were mainly localized in the transverse GMC faces, while in the advanced GMCs they appeared both in the transverse and the lateral ones adjacent to SMCs. Considering that phosphatidyl-inositol-3-kinase (PI3K) is an active component of auxin signal transduction and that phospholipid signaling contributes in the establishment of polarity, treatments with the specific inhibitor of the PI3K LY294002 were carried out. The presence of LY294002 suppressed polarization of SMCs and prevented their asymmetrical division, whereas combined treatment with exogenously added NAA and LY294002 restricted the promotional auxin influence on subsidiary cell formation. These findings support the view that auxin is involved in Z. mays subsidiary cell formation, probably functioning as inducer of the asymmetrical SMC division. Collectively, the results obtained from treatments with auxin transport inhibitors and the appearance of PIN1 proteins in the lateral GMC faces indicate a local transfer of auxin from GMCs to SMCs. Moreover, auxin signal transduction seems to be mediated by the catalytic function of PI3K.
Pantelis Livanos; Eleni Giannoutsou; Panagiotis Apostolakos; Basil Galatis. Auxin as an inducer of asymmetrical division generating the subsidiary cells in stomatal complexes ofZea mays. Plant Signaling & Behavior 2015, 10, e984531 -e984531.
AMA StylePantelis Livanos, Eleni Giannoutsou, Panagiotis Apostolakos, Basil Galatis. Auxin as an inducer of asymmetrical division generating the subsidiary cells in stomatal complexes ofZea mays. Plant Signaling & Behavior. 2015; 10 (3):e984531-e984531.
Chicago/Turabian StylePantelis Livanos; Eleni Giannoutsou; Panagiotis Apostolakos; Basil Galatis. 2015. "Auxin as an inducer of asymmetrical division generating the subsidiary cells in stomatal complexes ofZea mays." Plant Signaling & Behavior 10, no. 3: e984531-e984531.
The determination of the division plane in protodermal cells of the fern Asplenium nidus occurs during interphase with the formation of the phragmosome, the organization of which is controlled by the actomyosin system. Usually, the phragmosomes between adjacent cells were oriented on the same plane. In the phragmosomal cortical cytoplasm, an interphase microtubule (MT) ring was formed and large quantities of endoplasmic reticulum (ER) membranes were gathered, forming an interphase U-like ER bundle. During preprophase/prophase, the interphase MT ring and the U-like ER bundle were transformed into a MT and an ER preprophase band (PPB), respectively. Parts of the ER-PPB were maintained during mitosis. Furthermore, the plasmalemma as well as the nuclear envelope displayed local polarization on the phragmosome plane, while the cytoplasm between them was occupied by distinct ER aggregations. These consistent findings suggest that Α. nidus protodermal cells constitute a unique system in which three elements of the endomembrane system (ER, plasmalemma, and nuclear envelope) show specific characteristics in the establishing division plane. Our experimental data support that the organization of the U-like ER bundle is controlled on a cellular level by the actomyosin system and intercellularly by factors emitted from the leaf apex. The possible role of the above endomembrane system elements on the mechanism that coordinates the determination of the division plane between adjacent cells in protodermal tissue of A. nidus is discussed.
Eleni Giannoutsou; P. Sotiriou; P. Apostolakos; B. Galatis. Polarized endoplasmic reticulum aggregations in the establishing division plane of protodermal cells of the fern Asplenium nidus. Protoplasma 2014, 252, 181 -198.
AMA StyleEleni Giannoutsou, P. Sotiriou, P. Apostolakos, B. Galatis. Polarized endoplasmic reticulum aggregations in the establishing division plane of protodermal cells of the fern Asplenium nidus. Protoplasma. 2014; 252 (1):181-198.
Chicago/Turabian StyleEleni Giannoutsou; P. Sotiriou; P. Apostolakos; B. Galatis. 2014. "Polarized endoplasmic reticulum aggregations in the establishing division plane of protodermal cells of the fern Asplenium nidus." Protoplasma 252, no. 1: 181-198.
The morphogenesis of lobed mesophyll cells (MCs) is highly controlled and coupled with intercellular space formation. Cortical microtubule rings define the number and the position of MC isthmi. This work investigated early events of MC morphogenesis, especially the mechanism defining the position of contacts between MCs. The distributions of plasmodesmata, the hemicelluloses callose and (1 → 3,1 → 4)-β-d-glucans (MLGs) and the pectin epitopes recognized by the 2F4, JIM5, JIM7 and LM6 antibodies were studied in the cell walls of Zea mays MCs. Matrix cell wall polysaccharides were immunolocalized in hand-made sections and in sections of material embedded in LR White resin. Callose was also localized using aniline blue in hand-made sections. Plasmodesmata distribution was examined by transmission electron microscopy. Before reorganization of the dispersed cortical microtubules into microtubule rings, particular bands of the longitudinal MC walls, where the MC contacts will form, locally differentiate by selective (1) deposition of callose and the pectin epitopes recognized by the 2F4, LM6, JIM5 and JIM7 antibodies, (2) degradation of MLGs and (3) formation of secondary plasmodesmata clusterings. This cell wall matrix differentiation persists in cell contacts of mature MCs. Simultaneously, the wall bands between those of future cell contacts differentiate with (1) deposition of local cell wall thickenings including cellulose microfibrils, (2) preferential presence of MLGs, (3) absence of callose and (4) transient presence of the pectins identified by the JIM5 and JIM7 antibodies. The wall areas between cell contacts expand determinately to form the cell isthmi and the cell lobes. The morphogenesis of lobed MCs is characterized by the early patterned differentiation of two distinct cell wall subdomains, defining the sites of the future MC contacts and of the future MC isthmi respectively. This patterned cell wall differentiation precedes cortical microtubule reorganization and may define microtubule ring disposition.
Eleni Giannoutsou; P. Sotiriou; P. Apostolakos; B. Galatis. Early local differentiation of the cell wall matrix defines the contact sites in lobed mesophyll cells of Zea mays. Annals of Botany 2013, 112, 1067 -1081.
AMA StyleEleni Giannoutsou, P. Sotiriou, P. Apostolakos, B. Galatis. Early local differentiation of the cell wall matrix defines the contact sites in lobed mesophyll cells of Zea mays. Annals of Botany. 2013; 112 (6):1067-1081.
Chicago/Turabian StyleEleni Giannoutsou; P. Sotiriou; P. Apostolakos; B. Galatis. 2013. "Early local differentiation of the cell wall matrix defines the contact sites in lobed mesophyll cells of Zea mays." Annals of Botany 112, no. 6: 1067-1081.
We investigated the organization of the cortical endoplasmic reticulum (ER) in prophase cells of the angiosperms Zea mays, Triticum turgidum, and Vigna sinensis. In both symmetrically and asymmetrically dividing protodermal leaf cells, cortical ER was enriched in the preprophase band and colocalized there with microtubules, forming a ring‐like structure (ER ring). In contrast, ER ring was absent from prophase root‐tip cells of the same plants, suggesting that ER ring formation in the preprophase band is organ specific. Immunolabeling of the protodermal leaf cells revealed the presence of acetylated microtubules, which are more stable than the nonacetylated ones. In contrast, neither this post‐translational modification of tubulin nor an accumulation of ER in the preprophase band was detected in root‐tip cells. Experimentally delaying the maturation/disassembly of the microtubule ring of the preprophase band by taxol or cyclopiazonic acid treatment led to the appearance of ER ring and acetylated microtubules in the preprophase band. Together, our data show that in dividing cells of angiosperms, an ER ring associated with acetylated microtubules forms in the preprophase band. © 2012 Wiley Periodicals, Inc
Eleni Giannoutsou; Basil Galatis; Michael Zachariadis; Panagiotis Apostolakos. Formation of an endoplasmic reticulum ring associated with acetylated microtubules in the angiosperm preprophase band. Cytoskeleton 2012, 69, 252 -265.
AMA StyleEleni Giannoutsou, Basil Galatis, Michael Zachariadis, Panagiotis Apostolakos. Formation of an endoplasmic reticulum ring associated with acetylated microtubules in the angiosperm preprophase band. Cytoskeleton. 2012; 69 (4):252-265.
Chicago/Turabian StyleEleni Giannoutsou; Basil Galatis; Michael Zachariadis; Panagiotis Apostolakos. 2012. "Formation of an endoplasmic reticulum ring associated with acetylated microtubules in the angiosperm preprophase band." Cytoskeleton 69, no. 4: 252-265.
Two-phase olive-mill waste, the so-called “ecological”, has been treated with a Paecilomyces variotii isolate in solid state fermentation experiments. The growth of the microorganism was estimated by measuring the production of carbon dioxide, using gas chromatography. A 46% increase of the protein content was achieved at the fermented product, after molasses addition at the initial mixture. The amino acid profile of the produced protein, as far as the essential amino acids are concerned, was significantly improved, resulting in a product that has the potential to be used as animal feed. Furthermore, it contains lysine, one of the essential amino acids that did not exist at the original product and is produced during fermentation. This is the first report on solid state fermentation of the two-phase olive mill waste (TPOMW) as a substrate, using a Paecilomyces variotii strain.
E. P. Giannoutsou; E. A. Katsifas; A. Geli; A. D. Karagouni. Protein increase and lysine production by a Paecilomyces variotii strain grown on two-phase olive mill waste. World Journal of Microbiology and Biotechnology 2011, 28, 849 -856.
AMA StyleE. P. Giannoutsou, E. A. Katsifas, A. Geli, A. D. Karagouni. Protein increase and lysine production by a Paecilomyces variotii strain grown on two-phase olive mill waste. World Journal of Microbiology and Biotechnology. 2011; 28 (3):849-856.
Chicago/Turabian StyleE. P. Giannoutsou; E. A. Katsifas; A. Geli; A. D. Karagouni. 2011. "Protein increase and lysine production by a Paecilomyces variotii strain grown on two-phase olive mill waste." World Journal of Microbiology and Biotechnology 28, no. 3: 849-856.
Endoplasmic reticulum (ER) immunolabeling in developing stomatal complexes and in the intervening cells of the stomatal rows (ICSRs) of Zea mays revealed that the cortical-ER forms distinct aggregations lining locally expanding wall regions. The polarized subsidiary cell mother cells (SMCs), displayed a cortical-ER-patch lining the wall region shared with the inducing guard cell mother cell (GMC), which disorganized during mitosis. In dividing SMCs, ER persisted in the preprophase band region and was unequally distributed in the mitotic spindle poles. The subsidiary cells (SCs) formed initially an ER-patch lining the common wall with the GMC or the young guard cells and afterwards an ER-ring in the junction of the SC wall with the neighboring ones. Distinct ER aggregations lined the ICSR wall regions shared with the SCs. The cortical-ER aggregations in stomatal cells of Z. mays were co-localized with actin filament (AF) arrays but both were absent from the respective cells of Triticum turgidum, which follow a different morphogenetic pattern. Experimental evidence showed that the interphase ER aggregations are organized by the respective AF arrays, while the mitotic ER aggregations by microtubules. These results revealed that AF and ER demarcated “cortical cytoplasmic domains” are activated below the locally expanding stomatal cell wall regions, probably via a mechanosensing mechanism triggered by the locally stressed plasmalemma/cell wall continuum. The probable role(s) of the local ER aggregations are discussed.
Eleni Giannoutsou; Panagiotis Apostolakos; Basil Galatis. Actin filament-organized local cortical endoplasmic reticulum aggregations in developing stomatal complexes of grasses. Protoplasma 2010, 248, 373 -390.
AMA StyleEleni Giannoutsou, Panagiotis Apostolakos, Basil Galatis. Actin filament-organized local cortical endoplasmic reticulum aggregations in developing stomatal complexes of grasses. Protoplasma. 2010; 248 (2):373-390.
Chicago/Turabian StyleEleni Giannoutsou; Panagiotis Apostolakos; Basil Galatis. 2010. "Actin filament-organized local cortical endoplasmic reticulum aggregations in developing stomatal complexes of grasses." Protoplasma 248, no. 2: 373-390.
The presence of selected tetracycline resistance (TcR) genes was studied in different Greek seawater habitats, originated from wastewater treatment facilities, fishfarm, and coastal environments. The methods employed included assessment of the presence of twelve gene clusters by PCR, followed by hybridization with specific probes, in habitat extracted DNA, TcR bacteria, and exogenous isolated plasmids conferring TcR. The direct DNA-based analysis showed that tet(A) and tet(K) genes were detected in all habitats, whilst tet(C) and tet(E) were present in fishfarm and wastewater effluent samples and tet(M) was detected in fish-farm and coastal samples. Resistance genes tet(h), tet(C), tet(K), and tet(M) were detected in 60 of the 89 isolates screened. These isolates were identified by fatty acid methyl ester analysis (FAME) as Stenotrophomonas, Acinetobacter, Pseudomonas, Bacillus, and Staphylococcus strains. The presence of the TcR genes in 15% of the bacterial isolates coincided with the presence of IncP plasmids. A habitat-specific dissemination of IncP alpha plasmids in wastewater effluent isolates and of IncP beta plasmids in fishfarm isolates was observed. Exogenous isolation demonstrated the presence of plasmids harbouring TcR genes in all the habitats tested. Plasmids were shown to carry tet(h), tet(C), tet(E), and tet(K) genes. It is concluded that TcR genes are widespread in the seawater habitats studied and often occur on broad host range plasmids that seem to be well disseminated in the bacterial communities.
Theodora L. Nikolakopoulou; Eleni Giannoutsou; Adamandia A. Karabatsou; Amalia D. Karagouni. Prevalence of tetracycline resistance genes in Greek seawater habitats. Journal of Microbiology 2008, 46, 633 -640.
AMA StyleTheodora L. Nikolakopoulou, Eleni Giannoutsou, Adamandia A. Karabatsou, Amalia D. Karagouni. Prevalence of tetracycline resistance genes in Greek seawater habitats. Journal of Microbiology. 2008; 46 (6):633-640.
Chicago/Turabian StyleTheodora L. Nikolakopoulou; Eleni Giannoutsou; Adamandia A. Karabatsou; Amalia D. Karagouni. 2008. "Prevalence of tetracycline resistance genes in Greek seawater habitats." Journal of Microbiology 46, no. 6: 633-640.
A dynamic fed-batch microcosm system is described which permits assessment of the progressive growth of yeasts through olive oil waste. We report on its application to measure the effects of the growth of yeast strains upon the chemical composition of “alpeorujo”, the waste of a two-phase decanter system used for the extraction of olive oil. Six phenotypically distinct groups of yeasts were isolated. Three selected isolates were identified as being most closely related to Saccharomyces sp., Candida boidinii and Geotrichum candidum using biochemical tests and partial 18S rDNA gene sequence analysis. This is the first report of yeast growth on “alpeorujo” by the use of a fed-batch microcosm system, resulting in the change of the initial chemical composition of “alpeorujo” and in the decrease of the toxic substances such as phenols.
Eleni Giannoutsou; C. Meintanis; A.D. Karagouni. Identification of yeast strains isolated from a two-phase decanter system olive oil waste and investigation of their ability for its fermentation. Bioresource Technology 2004, 93, 301 -306.
AMA StyleEleni Giannoutsou, C. Meintanis, A.D. Karagouni. Identification of yeast strains isolated from a two-phase decanter system olive oil waste and investigation of their ability for its fermentation. Bioresource Technology. 2004; 93 (3):301-306.
Chicago/Turabian StyleEleni Giannoutsou; C. Meintanis; A.D. Karagouni. 2004. "Identification of yeast strains isolated from a two-phase decanter system olive oil waste and investigation of their ability for its fermentation." Bioresource Technology 93, no. 3: 301-306.
An Aspergillus carbonarius isolate, selected from an established microbial culture collection, was used to study the biodegradation of chromium shavings in solid-state fermentation experiments. Approximately 97% liquefaction of the tannery waste was achieved and the liquid obtained from long-term experiments was used to recover chromium. The resulting alkaline chromium sulfate solution was useful in tanning procedures. A proteinaceous liquid was also obtained which has potential applications as a fertilizer or animal feed additive and has several other industrial uses. The A. carbonarius strain proved to be a very useful tool in tannery waste-treatment processes and chromium recovery in the tanning industries.
E. A. Katsifas; Eleni Giannoutsou; M. Lambraki; M. Barla; A. D. Karagouni. Chromium recycling of tannery waste through microbial fermentation. Journal of Industrial Microbiology and Biotechnology 2004, 31, 57 -62.
AMA StyleE. A. Katsifas, Eleni Giannoutsou, M. Lambraki, M. Barla, A. D. Karagouni. Chromium recycling of tannery waste through microbial fermentation. Journal of Industrial Microbiology and Biotechnology. 2004; 31 (2):57-62.
Chicago/Turabian StyleE. A. Katsifas; Eleni Giannoutsou; M. Lambraki; M. Barla; A. D. Karagouni. 2004. "Chromium recycling of tannery waste through microbial fermentation." Journal of Industrial Microbiology and Biotechnology 31, no. 2: 57-62.
We systematically investigated the efficiency of Aspergillus nidulans transformation using protoplasts prepared from different stages of conidiospore germination and young mycelium. Using standard integrative plasmids, increased transformation yields were obtained with protoplasts isolated from a specific stage coincident with germ tube emergence. This increase ranged, on the average, from two- to eightfold depending on different plasmids used. Transformation efficiencies with a replicative plasmid were similar to those obtained using previously described methods. Although this observation suggests that elevated transformation efficiencies might be due to increased efficiency of recombination between plasmid and genomic sequences, we cannot exclude other factors associated with the particular developmental stage used. In the course of this study, we also examined the effect of other parameters that might enhance transformation yields. The method described is also significantly easier and faster than other current methods.
Marina Koukaki; Eleni Giannoutsou; Amalia Karagouni; George Diallinas. A novel improved method for Aspergillus nidulans transformation. Journal of Microbiological Methods 2003, 55, 687 -695.
AMA StyleMarina Koukaki, Eleni Giannoutsou, Amalia Karagouni, George Diallinas. A novel improved method for Aspergillus nidulans transformation. Journal of Microbiological Methods. 2003; 55 (3):687-695.
Chicago/Turabian StyleMarina Koukaki; Eleni Giannoutsou; Amalia Karagouni; George Diallinas. 2003. "A novel improved method for Aspergillus nidulans transformation." Journal of Microbiological Methods 55, no. 3: 687-695.
The diversity of streptomycetes isolated from different Greek terrestrial ecosystems using phenotypic identification, and the relationship between the number of species and the number of isolates as a diversity index, was studied. A total of 344 Streptomyces strains have been isolated and identified from diverse sites in the Greek territory, such as heavily disturbed agricultural areas and preserved forest areas, and from specific rhizosphere ecosystems. According to phenotypic identification, these strains belonged to 19 different cluster groups with a Willcox probability > 0·8. Streptomyces cyaneus, Strep. albidoflavus, Strep. diastaticus and Strep. exfoliatus were the most common cluster groups isolated from at least six different habitats. On the other hand, there were cluster groups that appeared in only one or two habitats, such as Strep. griseoflavus, Strep. rimosus, Streptoverticillium blastmyceticum, Nocardia mediterranea and Strep. fulvissimus. The diversity indices among the different cluster groups of each sampling area indicated that the different habitats can be sub-divided into two main groups: rhizosphere habitats and non-rhizosphere habitats, showing that the rhizosphere is one of the most important factors which determines the population structure of a specific soil area.
E. A. Katsifas; Eleni Giannoutsou; A. D. Karagouni. Diversity of streptomycetes among specific Greek terrestrial ecosystems. Letters in Applied Microbiology 1999, 29, 48 -51.
AMA StyleE. A. Katsifas, Eleni Giannoutsou, A. D. Karagouni. Diversity of streptomycetes among specific Greek terrestrial ecosystems. Letters in Applied Microbiology. 1999; 29 (1):48-51.
Chicago/Turabian StyleE. A. Katsifas; Eleni Giannoutsou; A. D. Karagouni. 1999. "Diversity of streptomycetes among specific Greek terrestrial ecosystems." Letters in Applied Microbiology 29, no. 1: 48-51.