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The nematode species Meloidogyne incognita infects a large variety of cultivated crops and is one of nature’s most notorious pests. One cultivated plant which is prone to M. incognita infestation is the tomato. Knowing that in A. thaliana the PIN auxin efflux transporters distribution is being altered upon early invasion by M. incognita, the PIN1 allocation patterns in the giant cells of tomato plants after 15 and 25 days of infection were investigated. PIN1 was absent from the giant cells’ membrane in both assessment timings examined, indicating the maintenance of a local auxin maxima, which was also supported by IAA immunodetection. PIN1 distribution pattern could be attributed on either the nematodes nutritional needs throughout its life cycle or due to the tomato plants differential responses upon M. incognita infection.
Christianna Meidani; Eleni Giannoutsou; Konstantinos Telioglanidis; Nikoletta G. Ntalli; Ioannis-Dimosthenis S. Adamakis. PIN1 auxin efflux carrier absence in Meloidogyne incognita-induced root-knots of tomato plants. European Journal of Plant Pathology 2021, 1 -6.
AMA StyleChristianna Meidani, Eleni Giannoutsou, Konstantinos Telioglanidis, Nikoletta G. Ntalli, Ioannis-Dimosthenis S. Adamakis. PIN1 auxin efflux carrier absence in Meloidogyne incognita-induced root-knots of tomato plants. European Journal of Plant Pathology. 2021; ():1-6.
Chicago/Turabian StyleChristianna Meidani; Eleni Giannoutsou; Konstantinos Telioglanidis; Nikoletta G. Ntalli; Ioannis-Dimosthenis S. Adamakis. 2021. "PIN1 auxin efflux carrier absence in Meloidogyne incognita-induced root-knots of tomato plants." European Journal of Plant Pathology , no. : 1-6.
Botrytis cinerea, a fungal pathogen that causes gray mold, is damaging more than 200 plant species, and especially tomato. Photosystem II (PSII) responses in tomato (Solanum lycopersicum L.) leaves to Botrytis cinerea spore suspension application were evaluated by chlorophyll fluorescence imaging analysis. Hydrogen peroxide (H2O2) that was detected 30 min after Botrytis application with an increasing trend up to 240 min, is possibly convening tolerance against B. cinerea at short-time exposure, but when increasing at relative longer exposure, is becoming a damaging molecule. In accordance, an enhanced photosystem II (PSII) functionality was observed 30 min after application of B. cinerea, with a higher fraction of absorbed light energy to be directed to photochemistry (Φ PSΙΙ ). The concomitant increase in the photoprotective mechanism of non-photochemical quenching of photosynthesis (NPQ) resulted in a significant decrease in the dissipated non-regulated energy (Φ NO ), indicating a possible decreased singlet oxygen (1O2) formation, thus specifying a modified reactive oxygen species (ROS) homeostasis. Therefore, 30 min after application of Botrytis spore suspension, before any visual symptoms appeared, defense response mechanisms were triggered, with PSII photochemistry to be adjusted by NPQ in a such way that PSII functionality to be enhanced, but being fully inhibited at the application spot and the adjacent area, after longer exposure (240 min). Hence, the response of tomato PSII to B. cinerea, indicates a hormetic temporal response in terms of “stress defense response” and “toxicity”, expanding the features of hormesis to biotic factors also. The enhanced PSII functionality 30 min after Botrytis application can possible be related with the need of an increased sugar production that is associated with a stronger plant defense potential through the induction of defense genes.
Maria-Lavrentia Stamelou; Ilektra Sperdouli; Ioanna Pyrri; Ioannis-Dimosthenis Adamakis; Michael Moustakas. Hormetic Responses of Photosystem II in Tomato to Botrytis cinerea. Plants 2021, 10, 521 .
AMA StyleMaria-Lavrentia Stamelou, Ilektra Sperdouli, Ioanna Pyrri, Ioannis-Dimosthenis Adamakis, Michael Moustakas. Hormetic Responses of Photosystem II in Tomato to Botrytis cinerea. Plants. 2021; 10 (3):521.
Chicago/Turabian StyleMaria-Lavrentia Stamelou; Ilektra Sperdouli; Ioanna Pyrri; Ioannis-Dimosthenis Adamakis; Michael Moustakas. 2021. "Hormetic Responses of Photosystem II in Tomato to Botrytis cinerea." Plants 10, no. 3: 521.
Cytokinesis is accomplished in higher plants by the phragmoplast, creating and conducting the cell plate to separate daughter nuclei by a new cell wall. The microtubule-severing enzyme p60-katanin plays an important role in the centrifugal expansion and timely disappearance of phragmoplast microtubules. Consequently, aberrant structure and delayed expansion rate of the phragmoplast have been reported to occur in p60-katanin mutants. Here, the consequences of p60-katanin malfunction in cell plate/daughter wall formation were investigated by transmission electron microscopy (TEM), in root cells of the fra2 Arabidopsis thaliana loss-of-function mutant. In addition, deviations in the chemical composition of cell plate/new cell wall were identified by immunolabeling and confocal microscopy. It was found that, apart from defective phragmoplast microtubule organization, cell plates/new cell walls also appeared faulty in structure, being unevenly thick and perforated by large gaps. In addition, demethylesterified homogalacturonans were prematurely present in fra2 cell plates, while callose content was significantly lower than in the wild type. Furthermore, KNOLLE syntaxin disappeared from newly formed cell walls in fra2 earlier than in the wild type. Taken together, these observations indicate that delayed cytokinesis, due to faulty phragmoplast organization and expansion, results in a loss of synchronization between cell plate growth and its chemical maturation.
Emmanuel Panteris; Anna Kouskouveli; Dimitris Pappas; Ioannis-Dimosthenis Adamakis. Cytokinesis in fra2 Arabidopsis thaliana p60-katanin Mutant: Defects in Cell Plate/Daughter Wall Formation. International Journal of Molecular Sciences 2021, 22, 1405 .
AMA StyleEmmanuel Panteris, Anna Kouskouveli, Dimitris Pappas, Ioannis-Dimosthenis Adamakis. Cytokinesis in fra2 Arabidopsis thaliana p60-katanin Mutant: Defects in Cell Plate/Daughter Wall Formation. International Journal of Molecular Sciences. 2021; 22 (3):1405.
Chicago/Turabian StyleEmmanuel Panteris; Anna Kouskouveli; Dimitris Pappas; Ioannis-Dimosthenis Adamakis. 2021. "Cytokinesis in fra2 Arabidopsis thaliana p60-katanin Mutant: Defects in Cell Plate/Daughter Wall Formation." International Journal of Molecular Sciences 22, no. 3: 1405.
In recent years, due to the development of industrial and agricultural production, heavy metal contamination has attracted increasing attention. Aromatic and medicinal plant Salvia sclarea L. (clary sage) is classified to zinc (Zn) accumulators and considered as a potential plant for the phytoremediation of heavy metal polluted soils. In this study, an adaptation of clary sage to 900 µM (excess) Zn exposure for eight days in a hydroponic culture was investigated. The tolerance mechanisms under excess Zn exposure were assessed by evaluating changes in the nutrient uptake, leaf pigment and phenolic content, photosynthetic activity and leaf structural characteristics. The uptake and the distribution of Zn, as well as some essential elements such as: Ca, Mg, Fe, Mn and Cu, were examined by inductively coupled plasma mass spectrometry. The results revealed that Salvia sclarea is a Zn-accumulator plant that tolerates significantly high toxic levels of Zn in the leaves by increasing the leaf contents of Fe, Ca and Mn ions to protect the photosynthetic function and to stimulate the photosystem I (PSI) and photosystem II (PSII) activities. The exposure of clary sage to excess Zn significantly increased the synthesis of total phenolics and anthocyanins in the leaves; these play an important role in Zn detoxification and protection against oxidative stress. The lipid peroxidation and electrolyte leakage in leaves, used as clear indicators for heavy metal damage, were slightly increased. All these data highlight that Salvia sclarea is an economically interesting plant for the phytoextraction and/or phytostabilization of Zn-contaminated soils.
Anelia Dobrikova; Emilia Apostolova; Anetta Hanć; Ekaterina Yotsova; Preslava Borisova; Ilektra Sperdouli; Ioannis-Dimosthenis Adamakis; Michael Moustakas. Tolerance Mechanisms of the Aromatic and Medicinal Plant Salvia sclarea L. to Excess Zinc. Plants 2021, 10, 194 .
AMA StyleAnelia Dobrikova, Emilia Apostolova, Anetta Hanć, Ekaterina Yotsova, Preslava Borisova, Ilektra Sperdouli, Ioannis-Dimosthenis Adamakis, Michael Moustakas. Tolerance Mechanisms of the Aromatic and Medicinal Plant Salvia sclarea L. to Excess Zinc. Plants. 2021; 10 (2):194.
Chicago/Turabian StyleAnelia Dobrikova; Emilia Apostolova; Anetta Hanć; Ekaterina Yotsova; Preslava Borisova; Ilektra Sperdouli; Ioannis-Dimosthenis Adamakis; Michael Moustakas. 2021. "Tolerance Mechanisms of the Aromatic and Medicinal Plant Salvia sclarea L. to Excess Zinc." Plants 10, no. 2: 194.
Five-day exposure of clary sage (Salvia sclarea L.) to 100 μM cadmium (Cd) in hydroponics was sufficient to increase Cd concentrations significantly in roots and aboveground parts and affect negatively whole plant levels of calcium (Ca) and magnesium (Mg), since Cd competes for Ca channels, while reduced Mg concentrations are associated with increased Cd tolerance. Total zinc (Zn), copper (Cu), and iron (Fe) uptake increased but their translocation to the aboveground parts decreased. Despite the substantial levels of Cd in leaves, without any observed defects on chloroplast ultrastructure, an enhanced photosystem II (PSII) efficiency was observed, with a higher fraction of absorbed light energy to be directed to photochemistry (ΦPSΙΙ). The concomitant increase in the photoprotective mechanism of non-photochemical quenching of photosynthesis (NPQ) resulted in an important decrease in the dissipated non-regulated energy (ΦNO), modifying the homeostasis of reactive oxygen species (ROS), through a decreased singlet oxygen (1O2) formation. A basal ROS level was detected in control plant leaves for optimal growth, while a low increased level of ROS under 5 days Cd exposure seemed to be beneficial for triggering defense responses, and a high level of ROS out of the boundaries (8 days Cd exposure), was harmful to plants. Thus, when clary sage was exposed to Cd for a short period, tolerance mechanisms were triggered. However, exposure to a combination of Cd and high light or to Cd alone (8 days) resulted in an inhibition of PSII functionality, indicating Cd toxicity. Thus, the rapid activation of PSII functionality at short time exposure and the inhibition at longer duration suggests a hormetic response and describes these effects in terms of “adaptive response” and “toxicity”, respectively.
Ioannis-Dimosthenis S. Adamakis; Ilektra Sperdouli; Anetta Hanć; Anelia Dobrikova; Emilia Apostolova; Michael Moustakas. Rapid Hormetic Responses of Photosystem II Photochemistry of Clary Sage to Cadmium Exposure. International Journal of Molecular Sciences 2020, 22, 41 .
AMA StyleIoannis-Dimosthenis S. Adamakis, Ilektra Sperdouli, Anetta Hanć, Anelia Dobrikova, Emilia Apostolova, Michael Moustakas. Rapid Hormetic Responses of Photosystem II Photochemistry of Clary Sage to Cadmium Exposure. International Journal of Molecular Sciences. 2020; 22 (1):41.
Chicago/Turabian StyleIoannis-Dimosthenis S. Adamakis; Ilektra Sperdouli; Anetta Hanć; Anelia Dobrikova; Emilia Apostolova; Michael Moustakas. 2020. "Rapid Hormetic Responses of Photosystem II Photochemistry of Clary Sage to Cadmium Exposure." International Journal of Molecular Sciences 22, no. 1: 41.
Microcystins (MCs) are cyanobacterial toxins and potent inhibitors of protein phosphatases 1 (PP1) and 2A (PP2A), which are involved in plant cytoskeleton (microtubules and F-actin) organization. Therefore, studies on the toxicity of cyanobacterial products on plant cells have so far been focused on MCs. In this study, we investigated the effects of extracts from 16 (4 MC-producing and 12 non-MC-producing) cyanobacterial strains from several habitats, on various enzymes (PP1, trypsin, elastase), on the plant cytoskeleton and H2O2 levels in Oryza sativa (rice) root cells. Seedling roots were treated for various time periods (1, 12, and 24 h) with aqueous cyanobacterial extracts and underwent either immunostaining for α-tubulin or staining of F-actin with fluorescent phalloidin. 2,7-dichlorofluorescein diacetate (DCF-DA) staining was performed for H2O2 imaging. The enzyme assays confirmed the bioactivity of the extracts of not only MC-rich (MC+), but also MC-devoid (MC−) extracts, which induced major time-dependent alterations on both components of the plant cytoskeleton. These findings suggest that a broad spectrum of bioactive cyanobacterial compounds, apart from MCs or other known cyanotoxins (such as cylindrospermopsin), can affect plants by disrupting the cytoskeleton.
Dimitris Pappas; Manthos Panou; Ioannis-Dimosthenis S. Adamakis; Spyros Gkelis; Emmanuel Panteris. Beyond Microcystins: Cyanobacterial Extracts Induce Cytoskeletal Alterations in Rice Root Cells. International Journal of Molecular Sciences 2020, 21, 9649 .
AMA StyleDimitris Pappas, Manthos Panou, Ioannis-Dimosthenis S. Adamakis, Spyros Gkelis, Emmanuel Panteris. Beyond Microcystins: Cyanobacterial Extracts Induce Cytoskeletal Alterations in Rice Root Cells. International Journal of Molecular Sciences. 2020; 21 (24):9649.
Chicago/Turabian StyleDimitris Pappas; Manthos Panou; Ioannis-Dimosthenis S. Adamakis; Spyros Gkelis; Emmanuel Panteris. 2020. "Beyond Microcystins: Cyanobacterial Extracts Induce Cytoskeletal Alterations in Rice Root Cells." International Journal of Molecular Sciences 21, no. 24: 9649.
Microcystins (MCs) are cyanobacterial toxins and potent inhibitors of protein phosphatases 1 (PP1) and 2A (PP2A), which are involved in plant cytoskeleton (microtubules and F-actin) organization. Therefore, studies on the toxicity of cyanobacterial products on plant cells have so far being focused on MCs. In this study, we investigated the effects of extracts from 16 (4 MC-producing and 12 non-MC-producing) cyanobacterial strains from several habitats, on various enzymes (PP1, trypsin, elastase), on the plant cytoskeleton and H2O2 levels in Oryza sativa (rice) root cells. Seedling roots were treated for various time periods (1, 12 and 24h) with aqueous cyanobacterial extracts and underwent either immunostaining for α-tubulin or staining of F-actin with fluorescent phalloidin. DCF-DA staining was performed for H2O2 imaging. The enzyme assays confirmed the bioactivity of the extracts of not only MC-rich (MC+), but also MC-devoid (MC-) extracts, which induced major time-dependent alterations on both components of the plant cytoskeleton. These findings suggest that a broad spectrum of bioactive cyanobacterial compounds, apart from MCs or other known cyanotoxins (such as cylindrospermopsin), can affect plants by disrupting the cytoskeleton.
Dimitris Pappas; Manthos Panou; Ioannis-Dimosthenis S. Adamakis; Spyros Gkelis; Emmanuel Panteris. Beyond Microcystins: Cyanobacterial Extracts Induce Cytoskeletal Alterations in Rice Root Cells. 2020, 1 .
AMA StyleDimitris Pappas, Manthos Panou, Ioannis-Dimosthenis S. Adamakis, Spyros Gkelis, Emmanuel Panteris. Beyond Microcystins: Cyanobacterial Extracts Induce Cytoskeletal Alterations in Rice Root Cells. . 2020; ():1.
Chicago/Turabian StyleDimitris Pappas; Manthos Panou; Ioannis-Dimosthenis S. Adamakis; Spyros Gkelis; Emmanuel Panteris. 2020. "Beyond Microcystins: Cyanobacterial Extracts Induce Cytoskeletal Alterations in Rice Root Cells." , no. : 1.
Five-day exposure of clary sage (Salvia sclarea) to 100 μM cadmium (Cd) in hydroponics was sufficient to increase Cd concentrations significantly in roots and aboveground parts and affect negatively whole plant levels of calcium (Ca) and magnesium (Mg), since Cd competes for Ca channels, while reduced Mg concentrations are associated with increased Cd tolerance. Total zinc (Zn), copper (Cu), and iron (Fe) uptake increased but their translocation to the aboveground parts decreased possible due to translocation barriers. Despite the substantial levels of Cd in leaves, without any observed defects on chloroplast ultrastructure, an enhanced photosystem II (PSII) efficiency was observed, with a higher fraction of absorbed light energy to be directed to photochemistry (ΦPSΙΙ). The concomitant increase in the photoprotective mechanism of non-photochemical quenching of photosynthesis (NPQ) resulted in an important decrease in the dissipated non-regulated energy (ΦNO), modifying the homeostasis of reactive oxygen species (ROS), through a decreased singlet oxygen (1O2) formation. Thus, when clary sage was exposed to Cd for a short period, tolerance mechanisms were triggered, with PSII photochemistry to be regulated by NPQ in such a way that PSII efficiency to be enhanced. However, exposure to a combination of Cd and high light or for longer duration (8 days) to Cd alone, resulted in an inhibition of PSII functionality pointing out towards Cd toxicity. Thus, the rapid activation of PSII functionality at short time exposures and the inhibition at longer duration suggests a hormetic response and describes these effects in terms of “adaptive response” and “toxicity”, respectively.
Ioannis-Dimosthenis S. Adamakis; Ilektra Sperdouli; Anetta Hanć; Anelia Dobrikova; Emilia Apostolova; Michael Moustakas. Rapid Hormetic Responses of Photosystem II Photochemistry to Cadmium Exposure. 2020, 1 .
AMA StyleIoannis-Dimosthenis S. Adamakis, Ilektra Sperdouli, Anetta Hanć, Anelia Dobrikova, Emilia Apostolova, Michael Moustakas. Rapid Hormetic Responses of Photosystem II Photochemistry to Cadmium Exposure. . 2020; ():1.
Chicago/Turabian StyleIoannis-Dimosthenis S. Adamakis; Ilektra Sperdouli; Anetta Hanć; Anelia Dobrikova; Emilia Apostolova; Michael Moustakas. 2020. "Rapid Hormetic Responses of Photosystem II Photochemistry to Cadmium Exposure." , no. : 1.
The organic pollutant bisphenol A (BPA) causes adverse effects on aquatic biota. The present study explored the toxicity mechanism of environmentally occurring BPA concentrations (0.03-3 μg L−1) on the seagrass Cymodocea nodosa intermediate leaf photosynthetic machinery. A "mosaic" type BPA effect pattern was observed, with “unaffected” and “affected” leaf areas. In negatively affected leaf areas cells had a dark appearance and lost their chlorophyll auto-fluorescence, while hydrogen peroxide (H2O2) content increased time-dependently. In the “unaffected” leaf areas, cells exhibited increased phenolic compound production. At 1 μg L-1 of BPA exposure, there was no effect on the fraction of open reaction centers (qP) compared to control and also no significant effect on the quantum yield of non-regulated non-photochemical energy loss in PSII (ΦΝΟ). However, a 3 μg L−1 BPA application resulted in a significant ΦΝΟ increase, even from the first exposure day. Ultrastructural observations revealed electronically dense damaged thylakoids in the plastids, while effects on Golgi dictyosomes and the endoplasmic reticulum were also observed at 3 μg L−1 BPA. The up-regulated H2O2 BPA-derived production seems to be a key factor causing both oxidative damages but probably also triggering retrograde signalling, conferring tolerance to BPA in the “unaffected” leaf areas.
Ioannis-Dimosthenis S. Adamakis; Paraskevi Malea; Ilektra Sperdouli; Emmanuel Panteris; Danae Kokkinidi; Michael Moustakas. Evaluation of the spatiotemporal effects of bisphenol A on the leaves of the seagrass Cymodocea nodosa. Journal of Hazardous Materials 2020, 404, 124001 .
AMA StyleIoannis-Dimosthenis S. Adamakis, Paraskevi Malea, Ilektra Sperdouli, Emmanuel Panteris, Danae Kokkinidi, Michael Moustakas. Evaluation of the spatiotemporal effects of bisphenol A on the leaves of the seagrass Cymodocea nodosa. Journal of Hazardous Materials. 2020; 404 ():124001.
Chicago/Turabian StyleIoannis-Dimosthenis S. Adamakis; Paraskevi Malea; Ilektra Sperdouli; Emmanuel Panteris; Danae Kokkinidi; Michael Moustakas. 2020. "Evaluation of the spatiotemporal effects of bisphenol A on the leaves of the seagrass Cymodocea nodosa." Journal of Hazardous Materials 404, no. : 124001.
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.
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.
In this study, for a first time (according to our knowledge), we couple the methodologies of chlorophyll fluorescence imaging analysis (CF-IA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), in order to investigate the effects of cadmium (Cd) accumulation on photosystem II (PSII) photochemistry. We used as plant material Salvia sclarea that grew hydroponically with or without (control) 100 μM Cd for five days. The spatial heterogeneity of a decreased effective quantum yield of electron transport (ΦPSΙΙ) that was observed after exposure to Cd was linked to the spatial pattern of high Cd accumulation. However, the high increase of non-photochemical quenching (NPQ), at the leaf part with the high Cd accumulation, resulted in the decrease of the quantum yield of non-regulated energy loss (ΦNO) even more than that of control leaves. Thus, S. sclarea leaves exposed to 100 μM Cd exhibited lower reactive oxygen species (ROS) production as singlet oxygen (1O2). In addition, the increased photoprotective heat dissipation (NPQ) in the whole leaf under Cd exposure was sufficient enough to retain the same fraction of open reaction centers (qp) with control leaves. Our results demonstrated that CF-IA and LA-ICP-MS could be successfully combined to monitor heavy metal effects and plant tolerance mechanisms.
Michael Moustakas; Anetta Hanć; Anelia Dobrikova; Ilektra Sperdouli; Ioannis-Dimosthenis S. Adamakis; Emilia Apostolova. Spatial Heterogeneity of Cadmium Effects on Salvia sclarea Leaves Revealed by Chlorophyll Fluorescence Imaging Analysis and Laser Ablation Inductively Coupled Plasma Mass Spectrometry. Materials 2019, 12, 2953 .
AMA StyleMichael Moustakas, Anetta Hanć, Anelia Dobrikova, Ilektra Sperdouli, Ioannis-Dimosthenis S. Adamakis, Emilia Apostolova. Spatial Heterogeneity of Cadmium Effects on Salvia sclarea Leaves Revealed by Chlorophyll Fluorescence Imaging Analysis and Laser Ablation Inductively Coupled Plasma Mass Spectrometry. Materials. 2019; 12 (18):2953.
Chicago/Turabian StyleMichael Moustakas; Anetta Hanć; Anelia Dobrikova; Ilektra Sperdouli; Ioannis-Dimosthenis S. Adamakis; Emilia Apostolova. 2019. "Spatial Heterogeneity of Cadmium Effects on Salvia sclarea Leaves Revealed by Chlorophyll Fluorescence Imaging Analysis and Laser Ablation Inductively Coupled Plasma Mass Spectrometry." Materials 12, no. 18: 2953.
Young and mature leaves of Arabidopsis thaliana were exposed by foliar spray to 30 mg L−1 of CuZn nanoparticles (NPs). The NPs were synthesized by a microwave-assisted polyol process and characterized by dynamic light scattering (DLS), X-ray diffraction (XRD), and transmission electron microscopy (TEM). CuZn NPs effects in Arabidopsis leaves were evaluated by chlorophyll fluorescence imaging analysis that revealed spatiotemporal heterogeneity of the quantum efficiency of PSII photochemistry (ΦPSΙΙ) and the redox state of the plastoquinone (PQ) pool (qp), measured 30 min, 90 min, 180 min, and 240 min after spraying. Photosystem II (PSII) function in young leaves was observed to be negatively influenced, especially 30 min after spraying, at which point increased H2O2 generation was correlated to the lower oxidized state of the PQ pool.. Recovery of young leaves photosynthetic efficiency appeared only after 240 min of NPs spray when also the level of ROS accumulation was similar to control leaves. On the contrary, a beneficial effect on PSII function in mature leaves after 30 min of the CuZn NPs spray was observed, with increased ΦPSΙΙ, an increased electron transport rate (ETR), decreased singlet oxygen (1O2) formation, and H2O2 production at the same level of control leaves.An explanation for this differential response is suggested.
Ilektra Sperdouli; Julietta Moustaka; Orestis Antonoglou; Ioannis-Dimosthenis S. Adamakis; Catherine Dendrinou-Samara; Michael Moustakas. Leaf Age-Dependent Effects of Foliar-Sprayed CuZn Nanoparticles on Photosynthetic Efficiency and ROS Generation in Arabidopsis thaliana. Materials 2019, 12, 2498 .
AMA StyleIlektra Sperdouli, Julietta Moustaka, Orestis Antonoglou, Ioannis-Dimosthenis S. Adamakis, Catherine Dendrinou-Samara, Michael Moustakas. Leaf Age-Dependent Effects of Foliar-Sprayed CuZn Nanoparticles on Photosynthetic Efficiency and ROS Generation in Arabidopsis thaliana. Materials. 2019; 12 (15):2498.
Chicago/Turabian StyleIlektra Sperdouli; Julietta Moustaka; Orestis Antonoglou; Ioannis-Dimosthenis S. Adamakis; Catherine Dendrinou-Samara; Michael Moustakas. 2019. "Leaf Age-Dependent Effects of Foliar-Sprayed CuZn Nanoparticles on Photosynthetic Efficiency and ROS Generation in Arabidopsis thaliana." Materials 12, no. 15: 2498.
The effects of bisphenol A (BPA), a prevalent endocrine disruptor, on both interphase and mitotic microtubule array organization was examined by immunofluorescence microscopy in meristematic root cells of Triticum turgidum (durum wheat) and Allium cepa (onion). In interphase cells of A. cepa, BPA treatment resulted in substitution of cortical microtubules by annular/spiral tubulin structures, while in T. turgidum BPA induced cortical microtubule fragmentation. Immunolocalization of acetylated α-tubulin revealed that cortical microtubules of T. turgidum were highly acetylated, unlike those of A. cepa. In addition, elevation of tubulin acetylation by trichostatin A in A. cepa resulted in microtubule disruption similar to that observed in T. turgidum. BPA also disrupted all mitotic microtubule arrays in both species. It is also worth noting that mitotic microtubule arrays were acetylated in both plants. As assessed by BPA removal, its effects are reversible. Furthermore, taxol-stabilized microtubules were resistant to BPA, while recovery from oryzalin treatment in BPA solution resulted in the formation of ring-like tubulin conformations. Overall, these findings indicate the following: (1) BPA affects plant mitosis/cytokinesis by disrupting microtubule organization. (2) Microtubule disassembly probably results from impairment of free tubulin subunit polymerization. (3) The differences in cortical microtubule responses to BPA among the species studied are correlated to the degree of tubulin acetylation.
Ioannis-Dimosthenis S. Adamakis; Emmanuel Panteris; Eleftherios P. Eleftheriou. Tubulin Acetylation Mediates Bisphenol A Effects on the Microtubule Arrays of Allium cepa and Triticum turgidum. Biomolecules 2019, 9, 185 .
AMA StyleIoannis-Dimosthenis S. Adamakis, Emmanuel Panteris, Eleftherios P. Eleftheriou. Tubulin Acetylation Mediates Bisphenol A Effects on the Microtubule Arrays of Allium cepa and Triticum turgidum. Biomolecules. 2019; 9 (5):185.
Chicago/Turabian StyleIoannis-Dimosthenis S. Adamakis; Emmanuel Panteris; Eleftherios P. Eleftheriou. 2019. "Tubulin Acetylation Mediates Bisphenol A Effects on the Microtubule Arrays of Allium cepa and Triticum turgidum." Biomolecules 9, no. 5: 185.
Previous studies have shown that excess tungsten (W), a rare heavy metal, is toxic to plant cells and may induce a kind of programmed cell death (PCD). In the present study we used transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM) to investigate the subcellular malformations caused by W, supplied as 200 mg/L sodium tungstate (Na2WO4) for 12 or 24 h, in root tip cells of Pisum sativum (pea), The objective was to provide additional evidence in support of the notion of PCD induction and the presumed involvement of reactive oxygen species (ROS). It is shown ultrastructurally that W inhibited seedling growth, deranged root tip morphology, induced the collapse and deformation of vacuoles, degraded Golgi bodies, increased the incidence of multivesicular and multilamellar bodies, and caused the detachment of the plasma membrane from the cell walls. Plastids and mitochondria were also affected. By TEM, the endoplasmic reticulum appeared in aggregations of straight, curved or concentric cisternae, frequently enclosing cytoplasmic organelles, while by CLSM it appeared in bright ring-like aggregations and was severely disrupted in mitotic cells. However, no evidence of ROS increase was obtained. Overall, these findings support the view of a W-induced vacuolar destructive PCD without ROS enhancement.
Ioannis-Dimosthenis S. Adamakis; Eleftherios P. Eleftheriou. Structural Evidence of Programmed Cell Death Induction by Tungsten in Root Tip Cells of Pisum sativum. Plants 2019, 8, 62 .
AMA StyleIoannis-Dimosthenis S. Adamakis, Eleftherios P. Eleftheriou. Structural Evidence of Programmed Cell Death Induction by Tungsten in Root Tip Cells of Pisum sativum. Plants. 2019; 8 (3):62.
Chicago/Turabian StyleIoannis-Dimosthenis S. Adamakis; Eleftherios P. Eleftheriou. 2019. "Structural Evidence of Programmed Cell Death Induction by Tungsten in Root Tip Cells of Pisum sativum." Plants 8, no. 3: 62.
Bisphenol A (BPA) is an emerging pollutant of environmental concern, classified as "moderately toxic" and "toxic", causing adverse effects on aquatic biota. Although information about BPA toxicity on aquatic fauna is available, the data about BPA effects on aquatic flora remain scarce, missing for marine macrophytes. The effects of environmentally relevant BPA concentrations (ranging from 0.03 to 3 μg L) on juvenile leaf elongation and the cytoskeleton (microtubules, MTs and actin filaments, AFs) were studied in the seagrass Cymodocea nodosa for 1-10 days. The suitability of cytoskeleton disturbance and leaf elongation impairment as "biomarkers" for BPA stress were tested. The highest BPA concentrations (0.3, 0.5, 1 and 3 μg L) affected significantly leaf elongation from the onset of the experiment, while defects of the cytoskeleton were observed even at lower concentrations. In particular, MTs were initially disrupted (i.e. "lowest observed effect concentrations", LOECs) at 0.1 μg L, while AFs were damaged even at 0.03 μg L. AFs appeared thus to be more sensitive to lower BPA concentrations, while there was a correlation between leaf elongation impairment and MT defects. Thus, AF damages, MT disruption and leaf elongation impairment in C. nodosa, in this particular order, appear to be sensitive "biomarkers" of BPA stress, at the above environmentally relevant BPA concentrations.
Ioannis-Dimosthenis S. Adamakis; Paraskevi Malea; Emmanuel Panteris. The effects of Bisphenol A on the seagrass Cymodocea nodosa: Leaf elongation impairment and cytoskeleton disturbance. Ecotoxicology and Environmental Safety 2018, 157, 431 -440.
AMA StyleIoannis-Dimosthenis S. Adamakis, Paraskevi Malea, Emmanuel Panteris. The effects of Bisphenol A on the seagrass Cymodocea nodosa: Leaf elongation impairment and cytoskeleton disturbance. Ecotoxicology and Environmental Safety. 2018; 157 ():431-440.
Chicago/Turabian StyleIoannis-Dimosthenis S. Adamakis; Paraskevi Malea; Emmanuel Panteris. 2018. "The effects of Bisphenol A on the seagrass Cymodocea nodosa: Leaf elongation impairment and cytoskeleton disturbance." Ecotoxicology and Environmental Safety 157, no. : 431-440.
Transverse cortical microtubule orientation, critical for anisotropic cell expansion, is established in the meristematic root zone. Intending to elucidate the possible prerequisites for this establishment and factors that are involved, microtubule organization was studied in roots of Arabidopsis thaliana, wild-type and the p60-katanin mutants fra2, ktn1-2 and lue1. Transverse cortical microtubule orientation in the meristematic root zone has proven to persist under several regimes inhibiting root elongation. This persistence was attributed to the constant moderate elongation of meristematic cells, prior to mitotic division. Therefore, A. thaliana wild-type seedlings were treated with aphidicolin, in order to prevent mitosis and inhibit premitotic cell elongation. In roots treated with aphidicolin for 12 h, cell divisions still occurred and microtubules were transverse. After 24 and 48 h of treatment, meristematic cell divisions and the prerequisite elongation ceased, while microtubule orientation became random. In meristematic cells of the p60-katanin mutants, apart from a general transverse microtubule pattern, cortical microtubules with random orientation were observed, also converging at several cortical sites, in contrast to the uniform transverse pattern of wild-type cells. Taken together, these observations reveal that transverse cortical microtubule orientation in the meristematic zone of A. thaliana root is cell division-dependent and requires severing by katanin.
Emmanuel Panteris; Barbara-Evelin Diannelidis; Ioannis-Dimosthenis S. Adamakis. Cortical microtubule orientation in Arabidopsis thaliana root meristematic zone depends on cell division and requires severing by katanin. Journal of Biological Research-Thessaloniki 2018, 25, 12 .
AMA StyleEmmanuel Panteris, Barbara-Evelin Diannelidis, Ioannis-Dimosthenis S. Adamakis. Cortical microtubule orientation in Arabidopsis thaliana root meristematic zone depends on cell division and requires severing by katanin. Journal of Biological Research-Thessaloniki. 2018; 25 (1):12.
Chicago/Turabian StyleEmmanuel Panteris; Barbara-Evelin Diannelidis; Ioannis-Dimosthenis S. Adamakis. 2018. "Cortical microtubule orientation in Arabidopsis thaliana root meristematic zone depends on cell division and requires severing by katanin." Journal of Biological Research-Thessaloniki 25, no. 1: 12.
Bisphenol A (BPA) is a widespread environmental pollutant, reportedly harmful to living organisms. In plant cells, BPA was shown to disrupt microtubule (MT) arrays and perturb mitosis, but its effects on filamentous actin (F-actin) have not been explored. Here we studied the effects of BPA on actin filaments (AFs) in meristematic root tip and leaf cells of Zea mays, by fluorescent labeling and confocal microscopy. Considering the typical dynamic interaction between MTs and AFs, the effects on these two essential components of the plant cytoskeleton were correlated. It was found that BPA disorganized rapidly AFs in a concentration- and time-dependent manner. The fine filaments were first to be affected, followed by the subcortical bundles, resulting in rod- and ring-like conformations. The observed differences in sensitivity between protodermal and cortex cells were attributed to the deeper location of the latter. Depolymerization or stabilization of MTs by relevant drugs (oryzalin, taxol) revealed that AF susceptibility to BPA depends on MT integrity. Developing leaves required harder and longer treatment to be affected by BPA. Ontogenesis of stomatal complexes was highly disturbed, arrangement of AFs and MT arrays was disordered and accuracy of cell division sequence was deranged or completely arrested. The effect of BPA confirmed that subsidiary cell mother cell polarization is not mediated by F-actin patch neither of preprophase band organization. On the overall, it is concluded that AFs in plant cells constitute a subcellular target of BPA and their disruption depends on their crosstalk with MTs.
Konstantina Stavropoulou; Ioannis-Dimosthenis S. Adamakis; Emmanuel Panteris; Ermioni-Makedonia Arseni; Eleftherios P. Eleftheriou. Disruption of actin filaments in Zea mays by bisphenol A depends on their crosstalk with microtubules. Chemosphere 2018, 195, 653 -665.
AMA StyleKonstantina Stavropoulou, Ioannis-Dimosthenis S. Adamakis, Emmanuel Panteris, Ermioni-Makedonia Arseni, Eleftherios P. Eleftheriou. Disruption of actin filaments in Zea mays by bisphenol A depends on their crosstalk with microtubules. Chemosphere. 2018; 195 ():653-665.
Chicago/Turabian StyleKonstantina Stavropoulou; Ioannis-Dimosthenis S. Adamakis; Emmanuel Panteris; Ermioni-Makedonia Arseni; Eleftherios P. Eleftheriou. 2018. "Disruption of actin filaments in Zea mays by bisphenol A depends on their crosstalk with microtubules." Chemosphere 195, no. : 653-665.
Highlights•BPA disrupted microtubules in all mitotic stages of Abies cephalonica.•Chromosomal aberrations were underlain by microtubule derangement under BPA stress.•Endoplasmic reticulum malformations reflected those of microtubules.•Microtubule recovery after oryzalin treatment was more effective in BPA than in water.•BPA-induced multipolar spindles are attributed to the centrosomal properties of gymnosperms. AbstractThe effects of bisphenol A (BPA), an endocrine chemical disruptor extensively used in the plastic and epoxy resin industry, on dividing root tip cells of the gymnosperm Abies cephalonica Loudon were investigated by confocal laser scanning microscopy after tubulin and endoplasmic reticulum immunolocalization and DNA staining. Microtubule arrays of all mitotic stages were disrupted within a few hours of treatment: preprophase bands exhibited asymmetric width; prometaphase, metaphase and anaphase spindles appeared sharply pointed, sigmoid or multipolar; phragmoplast microtubules were elongated and occasionally bended toward the daughter nuclei. Depending on the mitotic stage, the chromosomes appeared condensed at prophase, as a compact mass at metaphase and anaphase, unsegregated or bridged at telophase. Endoplasmic reticulum patterns were also affected, reflecting those of the respective microtubule arrays. Recovery of the microtubules after oryzalin treatment was more effective in a BPA solution than in water. It is concluded that the plant mitotic apparatus microtubules are very sensitive to BPA, the effect of which depends on the specific cell cycle stage. The formation of multipolar spindles is reminiscent of animal cells and is ascribed to the induction of multiple microtubule nucleation sites, deriving from the centrosomal properties of gymnosperms.
Ioannis-Dimosthenis S. Adamakis; Emmanuel Panteris; Eleftherios P. Eleftheriou. Bisphenol A disrupts microtubules and induces multipolar spindles in dividing root tip cells of the gymnosperm Abies cephalonica. Chemosphere 2016, 149, 202 -210.
AMA StyleIoannis-Dimosthenis S. Adamakis, Emmanuel Panteris, Eleftherios P. Eleftheriou. Bisphenol A disrupts microtubules and induces multipolar spindles in dividing root tip cells of the gymnosperm Abies cephalonica. Chemosphere. 2016; 149 ():202-210.
Chicago/Turabian StyleIoannis-Dimosthenis S. Adamakis; Emmanuel Panteris; Eleftherios P. Eleftheriou. 2016. "Bisphenol A disrupts microtubules and induces multipolar spindles in dividing root tip cells of the gymnosperm Abies cephalonica." Chemosphere 149, no. : 202-210.
Tungsten is a heavy metal with increasing concern over its environmental impact. In plants it is extensively used to deplete nitric oxide by inhibiting nitrate reductase, but its presumed toxicity as a heavy metal has been less explored. Accordingly, its effects on Arabidopsis thaliana primary root were assessed. The effects on root growth, mitotic cell percentage, nitric oxide and hydrogen peroxide levels, the cytoskeleton, cell ultrastructure, auxin and cytokinin activity, and auxin carrier distribution were investigated. It was found that tungsten reduced root growth, particularly by inhibiting cell expansion in the elongation zone, so that root hairs emerged closer to the root tip than in the control. Although extensive vacuolation was observed, even in meristematic cells, cell organelles were almost unaffected and microtubules were not depolymerized but reoriented. Tungsten affected auxin and cytokinin activity, as visualized by the DR5-GFP and TCS-GFP expressing lines, respectively. Cytokinin fluctuations were similar to those of the mitotic cell percentage. DR5-GFP signal appeared ectopically expressed, while the signals of PIN2-GFP and PIN3-GFP were diminished even after relatively short exposures. The observed effects were not reminiscent of those of any nitric oxide scavengers. Taken together, inhibition of root growth by tungsten might rather be related to a presumed interference with the basipetal flow of auxin, specifically affecting cell expansion in the elongation zone.
Ioannis-Dimosthenis S. Adamakis; Emmanuel Panteris; Eleftherios P. Eleftheriou. Tungsten disrupts root growth in Arabidopsis thaliana by PIN targeting. Journal of Plant Physiology 2014, 171, 1174 -1187.
AMA StyleIoannis-Dimosthenis S. Adamakis, Emmanuel Panteris, Eleftherios P. Eleftheriou. Tungsten disrupts root growth in Arabidopsis thaliana by PIN targeting. Journal of Plant Physiology. 2014; 171 (13):1174-1187.
Chicago/Turabian StyleIoannis-Dimosthenis S. Adamakis; Emmanuel Panteris; Eleftherios P. Eleftheriou. 2014. "Tungsten disrupts root growth in Arabidopsis thaliana by PIN targeting." Journal of Plant Physiology 171, no. 13: 1174-1187.