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With the aim to produce functional dairy products enriched with polyunsaturated fatty acids (PUFA) by using feed supplements, radical changes could occur in the rumen microbiome. This work investigated the alterations of the rumen bacteriome of goats fed with PUFA-rich marine microalgae Schizochytrium spp. For the trial, twenty-four goats were divided into four homogenous clusters (six goats/treatment) according to their fat-corrected (4%) milk yield, body weight, and age; they were individually fed with alfalfa hay and a concentrate (F/C = 50/50). The concentrate of the control group (CON) contained no microalgae, while those of the treated groups were supplemented daily with 20 (ALG20), 40 (ALG40), and 60 g (ALG60) of Schizochytrium spp./goat. Rumen fluid samples were collected using a stomach tube during the 20th and 40th days of the experiment. The microbiome analysis using a 16S rRNA sequencing platform revealed that Firmicutes were decreased in microalgae-fed goats, while Bacteroidetes showed a tendency to increase in the ALG40 group due to the enhancement of Prevotellaceae. Cellulolytic bacteria, namely Treponema bryantii, Ruminococcus gauvreauii, R. albus, and R. flavefaciens, were decreased in the ALG40 group, resulting in an overall decrease of cellulase activity. In contrast, the amylolytic potential was significantly enhanced due to an upsurge in Ruminobacter amylophilus, Succinivibrio dextrinosolvens, and Fretibacterium fastidiosum populations. In conclusion, supplementing goats’ diets with 20 g Schizochytrium spp. could be considered a sustainable and efficient nutritional strategy to modulate rumen microbiome towards the development of dairy products enriched with bioactive compounds, while higher levels induced substantial shifts in determinant microbes’ populations.
Alexandros Mavrommatis; Dimitrios Skliros; Emmanouil Flemetakis; Eleni Tsiplakou. Changes in the Rumen Bacteriome Structure and Enzymatic Activities of Goats in Response to Dietary Supplementation with Schizochytrium spp. Microorganisms 2021, 9, 1528 .
AMA StyleAlexandros Mavrommatis, Dimitrios Skliros, Emmanouil Flemetakis, Eleni Tsiplakou. Changes in the Rumen Bacteriome Structure and Enzymatic Activities of Goats in Response to Dietary Supplementation with Schizochytrium spp. Microorganisms. 2021; 9 (7):1528.
Chicago/Turabian StyleAlexandros Mavrommatis; Dimitrios Skliros; Emmanouil Flemetakis; Eleni Tsiplakou. 2021. "Changes in the Rumen Bacteriome Structure and Enzymatic Activities of Goats in Response to Dietary Supplementation with Schizochytrium spp." Microorganisms 9, no. 7: 1528.
Lytic bacteriophages have been well documented to play a pivotal role in microbial ecology due to their complex interactions with bacterial species, especially in aquatic habitats. Although the use of phages as antimicrobial agents, known as phage therapy, in the aquatic environment has been increasing, recent research has revealed drawbacks due to the development of phage-resistant strains among Gram-negative species. Acquired phage resistance in marine Vibrios has been proven to be a very complicated process utilizing biochemical, metabolic, and molecular adaptation strategies. The results of our multi-omics approach, incorporating transcriptome and metabolome analyses of Vibrio alginolyticus phage-resistant strains, corroborate this prospect. Our results provide insights into phage-tolerant strains diminishing the expression of phage receptors ompF, lamB, and btuB. The same pattern was observed for genes encoding natural nutrient channels, such as rbsA, ptsG, tryP, livH, lysE, and hisp, meaning that the cell needs to readjust its biochemistry to achieve phage resistance. The results showed reprogramming of bacterial metabolism by transcript regulations in key-metabolic pathways, such as the tricarboxylic acid cycle (TCA) and lysine biosynthesis, as well as the content of intracellular metabolites belonging to processes that could also significantly affect the cell physiology. Finally, SNP analysis in resistant strains revealed no evidence of amino acid alterations in the studied putative bacterial phage receptors, but several SNPs were detected in genes involved in transcriptional regulation. This phenomenon appears to be a phage-specific, fine-tuned metabolic engineering, imposed by the different phage genera the bacteria have interacted with, updating the role of lytic phages in microbial marine ecology.
Dimitrios Skliros; Panos Kalatzis; Chrysanthi Kalloniati; Fotios Komaitis; Sokratis Papathanasiou; Evangelia Kouri; Michael Udvardi; Constantina Kokkari; Pantelis Katharios; Emmanouil Flemetakis. The Development of Bacteriophage Resistance in Vibrio alginolyticus Depends on a Complex Metabolic Adaptation Strategy. Viruses 2021, 13, 656 .
AMA StyleDimitrios Skliros, Panos Kalatzis, Chrysanthi Kalloniati, Fotios Komaitis, Sokratis Papathanasiou, Evangelia Kouri, Michael Udvardi, Constantina Kokkari, Pantelis Katharios, Emmanouil Flemetakis. The Development of Bacteriophage Resistance in Vibrio alginolyticus Depends on a Complex Metabolic Adaptation Strategy. Viruses. 2021; 13 (4):656.
Chicago/Turabian StyleDimitrios Skliros; Panos Kalatzis; Chrysanthi Kalloniati; Fotios Komaitis; Sokratis Papathanasiou; Evangelia Kouri; Michael Udvardi; Constantina Kokkari; Pantelis Katharios; Emmanouil Flemetakis. 2021. "The Development of Bacteriophage Resistance in Vibrio alginolyticus Depends on a Complex Metabolic Adaptation Strategy." Viruses 13, no. 4: 656.
Whole sesame seeds (WSS) are rich in both linoleic acid (LA) and lignans. However, their impact on the innate immunity of goats is not well studied. Twenty-four goats were divided into three homogeneous sub-groups; comprise one control (CON) and two treated (WWS5 and WWS10). In the treated groups, WSS were incorporated in the concentrates of the CON at 5 (WSS5) and 10% (WSS10) respectively, by partial substitution of both soybean meal and corn grain. The expression levels of MAPK1, IL6, TRIF, IFNG, TRAF3, and JUND genes in the neutrophils of WSS10 fed goats were reduced significantly compared with the CON. The same was found for the expression levels of IFNG and TRAF3 genes in the neutrophils of WSS5 fed goats. Both treated groups primarily affected the MYD88-independent pathway. The dietary supplementation of goats with WSS might be a good nutritional strategy to improve their innate immunity.
Christina Mitsiopoulou; Kyriaki Sotirakoglou; Dimitrios Skliros; Emmanouil Flemetakis; Eleni Tsiplakou. The Impact of Whole Sesame Seeds on the Expression of Key-Genes Involved in the Innate Immunity of Dairy Goats. Animals 2021, 11, 468 .
AMA StyleChristina Mitsiopoulou, Kyriaki Sotirakoglou, Dimitrios Skliros, Emmanouil Flemetakis, Eleni Tsiplakou. The Impact of Whole Sesame Seeds on the Expression of Key-Genes Involved in the Innate Immunity of Dairy Goats. Animals. 2021; 11 (2):468.
Chicago/Turabian StyleChristina Mitsiopoulou; Kyriaki Sotirakoglou; Dimitrios Skliros; Emmanouil Flemetakis; Eleni Tsiplakou. 2021. "The Impact of Whole Sesame Seeds on the Expression of Key-Genes Involved in the Innate Immunity of Dairy Goats." Animals 11, no. 2: 468.
Fat rich microorganisms, such as microalgae Schizochytrium spp., are potential biotechnological tools in the modulation of rumen microbiome towards ecofriendly and high nutritional value end-products. However, limited in vivo trials have been reported on the topic. The aim of this study was to contribute to the knowledge on the effect of fat rich microalgae on the methanogenic and feed degrading particle-associated microbes in goats’ rumen content. For the trial, twenty-four goats were divided into four homogenous clusters (six goats/treatment) according to their fat corrected (4%) milk yield, body weight and age and individually were fed with alfalfa hay and concentrate feeds (F/C = 50/50). The concentrate of the control group (CON) contained no microalgae, while those of the treated groups were supplemented daily with 20 (ALG20), 40 (ALG40), and 60 (ALG60) g of Schizochytrium spp./goat. The relative abundances of total Archaea, methanogens, Methanomassiliicoccales, Methanobrevibacter spp., Methanosphaera stadmanae and Methanobacterium formicicum were significantly (p < 0.05) decreased in microalgae-fed goats compared to the CON ones. Moreover, a significant decline in the relative abundances of Firmicutes, Ruminococcus flavefaciens, Butyrivibrio fibrosolvents, and Neocallimastigales in the rumen particle-associated microbiota of microalgae supplemented goats were observed. In conclusion, goats’ diets supplementation with Schizochytrium spp., could be considered a sustainable nutritional strategy for methanogens inhibition in their rumen particle-associated microbiota.
Alexandros Mavrommatis; Dimitrios Skliros; Marica Simoni; Federico Righi; Emmanouil Flemetakis; Eleni Tsiplakou. Alterations in the Rumen Particle-Associated Microbiota of Goats in Response to Dietary Supplementation Levels of Schizochytrium spp. Sustainability 2021, 13, 607 .
AMA StyleAlexandros Mavrommatis, Dimitrios Skliros, Marica Simoni, Federico Righi, Emmanouil Flemetakis, Eleni Tsiplakou. Alterations in the Rumen Particle-Associated Microbiota of Goats in Response to Dietary Supplementation Levels of Schizochytrium spp. Sustainability. 2021; 13 (2):607.
Chicago/Turabian StyleAlexandros Mavrommatis; Dimitrios Skliros; Marica Simoni; Federico Righi; Emmanouil Flemetakis; Eleni Tsiplakou. 2021. "Alterations in the Rumen Particle-Associated Microbiota of Goats in Response to Dietary Supplementation Levels of Schizochytrium spp." Sustainability 13, no. 2: 607.
Sweet sorghum's high yielding ability, low-input demands and tolerance to stresses, render it highly suitable for syrup and bioenergy production. Exploiting its biomass, however is hampered by the seasonality of its production and the rapid post-harvest sugar catabolism degrading biomass quality. We aimed at elucidating aspects of sweet sorghum’s metabolism at different developmental and post-harvest stages, to investigate possibilities of expanding the harvesting window. GC–MS-mediated metabolic profiling was employed to monitor changes across growth stages and targeted transcriptomic analysis was used to determine the expression of genes involved in sucrose metabolism. Changes were studied both in the leaves and stems before, during and after the stage considered as optimum for harvest, whereas harvested stems were analyzed to determine post-harvest changes. Significant alterations in the levels of sugars, amino acids and organic acids were found, sugar levels attaining a maximum at soft dough stage. Overall data suggest that sugar metabolic content is regulated at transcriptional level, while temporal regulation of development and sucrose metabolism is under strong genotypic dependency. Although total sucrose levels were relatively lower at stems harvested one month past the optimum stage or harvested on time and piled for one month, compared to the optimum stage, losses encountered are adequately compensated by the prolonged period of biomass supply to the processing plants. It becomes evident that fine tuning of crop's harvesting and delivery time could significantly contribute to relaxing seasonality-related bottlenecks, thus upgrading the economic operation of plants utilizing sweet sorghum as a bioenergy crop.
Christos E. Vlachos; Ourania I. Pavli; Emmanouil Flemetakis; George N. Skaracis. Exploiting pre- and post-harvest metabolism in sweet sorghum genotypes to promote sustainable bioenergy production. Industrial Crops and Products 2020, 155, 112758 .
AMA StyleChristos E. Vlachos, Ourania I. Pavli, Emmanouil Flemetakis, George N. Skaracis. Exploiting pre- and post-harvest metabolism in sweet sorghum genotypes to promote sustainable bioenergy production. Industrial Crops and Products. 2020; 155 ():112758.
Chicago/Turabian StyleChristos E. Vlachos; Ourania I. Pavli; Emmanouil Flemetakis; George N. Skaracis. 2020. "Exploiting pre- and post-harvest metabolism in sweet sorghum genotypes to promote sustainable bioenergy production." Industrial Crops and Products 155, no. : 112758.
Omic technologies are a major source of information in understanding the cellular processes while their employment for studying microalgal biomass and productivity is rapidly expanding. Microalgae are known for their complex cellular metabolism. Environmental conditions affect intensely both their metabolic and transcriptomic profiles, resulting in production of numerous compounds with applications in pharmaceuticals, cosmetics, nutrition and biofuel. In an attempt to detect global changes occurring during environmental light alteration, an integrated omics approach was employed while the results were evaluated using different statistical approaches. An RT-qPCR based platform was utilized for the targeted transcript profiling of Nannochloropsis gaditana genes involved in primary and secondary metabolism, while the metabolite profiles were analyzed by GC–MS and GC-FID analytical methods. The combined transcriptomic and metabolomic results revealed extensive metabolic adaptations triggered by different chromatic qualities of light. In summary, an overall induction in both transcripts and metabolites, involved mainly in amino acid metabolism, was observed under red filtered light. Blue filtered light provoked decreased carbohydrate concentration but elevated polyunsaturated fatty acids content. Moreover, green filtered light induced the lowest responses in metabolite and gene transcript levels, indicating that its photons are poorly absorbed by N. gaditana. The current work suggests that spectral light changes leading to biochemical and metabolic manipulation of microalga N. gaditana can be accomplished by light filtering of solar irradiance, a cost-effective method which could be routinely applied in large scale photobioreactor cultivating systems.
Maria Patelou; Carlos Infante; Flavien Dardelle; Dörte Randewig; Evangelia D. Kouri; Michael K. Udvardi; Eleni Tsiplakou; Lalia Mantecón; Emmanouil Flemetakis. Transcriptomic and metabolomic adaptation of Nannochloropsis gaditana grown under different light regimes. Algal Research 2019, 45, 101735 .
AMA StyleMaria Patelou, Carlos Infante, Flavien Dardelle, Dörte Randewig, Evangelia D. Kouri, Michael K. Udvardi, Eleni Tsiplakou, Lalia Mantecón, Emmanouil Flemetakis. Transcriptomic and metabolomic adaptation of Nannochloropsis gaditana grown under different light regimes. Algal Research. 2019; 45 ():101735.
Chicago/Turabian StyleMaria Patelou; Carlos Infante; Flavien Dardelle; Dörte Randewig; Evangelia D. Kouri; Michael K. Udvardi; Eleni Tsiplakou; Lalia Mantecón; Emmanouil Flemetakis. 2019. "Transcriptomic and metabolomic adaptation of Nannochloropsis gaditana grown under different light regimes." Algal Research 45, no. : 101735.
Omic technologies in the past years have provided a variety of data in model plants. In legumes, results οn Lotus japonicus and Medicago truncatula have highlighted the biochemistry which takes place inside cells under a variety of abiotic stresses. Here we conducted metabolomics in the forage legume lentil (Lens culinaris) upon salinity stress on acclimated and non-acclimated plants and compared results from leaf and root analyses. We used two lentil varieties, originated from different geographical locations and studied differences in their global metabolite profile i) using gradual or initial application of salt stress, ii) between leaves and roots, and iii) between the varieties. Most important differences were noted in salinity induced diminished abundance of organic acids in both varieties’ leaves and roots, accumulation of sugars and polyols in leaves, and accumulation of other key-metabolites, such as L-asparagine, D-trehalose, allantoin and urea in the roots. We also demonstrated the driver of deleterious Cl− accumulation in leaves for potential compartmentalization in the vacuole, a defensive mechanism for withstanding salinity stress in plants. Finally, a model is suggested of how legumes upregulate a metabolic pathway, which involves purines catabolism in order to assimilate carbon and nitrogen, which are limited during salinity stress. Future omics works with lentil can help understanding the regulation of the biochemical “arsenal” against abiotic stresses such as salinity and render the selection of better crops.
Dimitrios Skliros; Chrysanthi Kalloniati; Georgios Karalias; George N. Skaracis; Heinz Rennenberg; Emmanouil Flemetakis. Global metabolomics analysis reveals distinctive tolerance mechanisms in different plant organs of lentil (Lens culinaris) upon salinity stress. Plant and Soil 2018, 429, 451 -468.
AMA StyleDimitrios Skliros, Chrysanthi Kalloniati, Georgios Karalias, George N. Skaracis, Heinz Rennenberg, Emmanouil Flemetakis. Global metabolomics analysis reveals distinctive tolerance mechanisms in different plant organs of lentil (Lens culinaris) upon salinity stress. Plant and Soil. 2018; 429 (1-2):451-468.
Chicago/Turabian StyleDimitrios Skliros; Chrysanthi Kalloniati; Georgios Karalias; George N. Skaracis; Heinz Rennenberg; Emmanouil Flemetakis. 2018. "Global metabolomics analysis reveals distinctive tolerance mechanisms in different plant organs of lentil (Lens culinaris) upon salinity stress." Plant and Soil 429, no. 1-2: 451-468.
The symbiotic nitrogen fixing legumes play an essential role in sustainable agriculture. White clover (Trifolium repens L.) is one of the most valuable perennial legumes in pastures and meadows of temperate regions. Despite its great agriculture and economic importance, there is no detailed available information on phylogenetic assignation and characterization of rhizobia associated with native white clover plants in South-Eastern Europe. In the present work, the diversity of indigenous white clover rhizobia originating in 11 different natural ecosystems in North-Eastern Romania were assessed by a polyphasic approach. Initial grouping showed that, 73 rhizobial isolates, representing seven distinct phenons were distributed into 12 genotypes, indicating a wide phenotypic and genotypic diversity among the isolates. To clarify their phylogeny, 44 representative strains were used in sequence analysis of 16S rRNA gene and IGS fragments, three housekeeping genes (atpD, glnII and recA) and two symbiosis-related genes (nodA and nifH). Multilocus sequence analysis (MLSA) phylogeny based on concatenated housekeeping genes delineated the clover isolates into five putative genospecies. Despite their diverse chromosomal backgrounds, test strains shared highly similar symbiotic genes closely related to Rhizobium leguminosarum biovar trifolii. Phylogenies inferred from housekeeping genes were incongruent with those of symbiotic genes, probably due to occurrence of lateral transfer events among native strains. This is the first polyphasic taxonomic study to report on the MLSA-based phylogenetic diversity of indigenous rhizobia nodulating white clover plants grown in various soil types in South-Eastern Europe. Our results provide valuable taxonomic data on native clover rhizobia and may increase the pool of genetic material to be used as biofertilizers.
Rodica C. Efrose; Craita M. Rosu; Catalina Stedel; Andrei Stefan; Culita Sirbu; Lucian D. Gorgan; Nikolaos E. Labrou; Emmanouil Flemetakis. Molecular diversity and phylogeny of indigenous Rhizobium leguminosarum strains associated with Trifolium repens plants in Romania. Antonie van Leeuwenhoek 2017, 111, 135 -153.
AMA StyleRodica C. Efrose, Craita M. Rosu, Catalina Stedel, Andrei Stefan, Culita Sirbu, Lucian D. Gorgan, Nikolaos E. Labrou, Emmanouil Flemetakis. Molecular diversity and phylogeny of indigenous Rhizobium leguminosarum strains associated with Trifolium repens plants in Romania. Antonie van Leeuwenhoek. 2017; 111 (1):135-153.
Chicago/Turabian StyleRodica C. Efrose; Craita M. Rosu; Catalina Stedel; Andrei Stefan; Culita Sirbu; Lucian D. Gorgan; Nikolaos E. Labrou; Emmanouil Flemetakis. 2017. "Molecular diversity and phylogeny of indigenous Rhizobium leguminosarum strains associated with Trifolium repens plants in Romania." Antonie van Leeuwenhoek 111, no. 1: 135-153.
Sequencing and annotation was performed for two giant double stranded DNA bacteriophages, φGrn1 and φSt2 of the Myoviridae family, considered to be of great interest for phage therapy against Vibrios in aquaculture live feeds. In addition, phage-host metabolic interactions and exploitation was studied by transcript profiling of selected viral and host genes. Comparative genomic analysis with other giant Vibrio phages was also performed to establish the presence and location of homing endonucleases highlighting distinct features for both phages. Phylogenetic analysis revealed that they belong to the “schizoT4like” clade. Although many reports of newly sequenced viruses have provided a large set of information, basic research related to the shift of the bacterial metabolism during infection remains stagnant. The function of many viral protein products in the process of infection is still unknown. Genome annotation identified the presence of several viral ORFs participating in metabolism, including a Sir2/cobB (sirtuin) protein and a number of genes involved in auxiliary NAD+ and nucleotide biosynthesis, necessary for phage DNA replication. Key genes were subsequently selected for detail study of their expression levels during infection. This work suggests a complex metabolic interaction and exploitation of the host metabolic pathways and biochemical processes, including a possible post-translational protein modification, by the virus during infection.
Dimitrios Skliros; Panos G. Kalatzis; Pantelis Katharios; Emmanouil Flemetakis. Comparative Functional Genomic Analysis of Two Vibrio Phages Reveals Complex Metabolic Interactions with the Host Cell. Frontiers in Microbiology 2016, 7, 1807 .
AMA StyleDimitrios Skliros, Panos G. Kalatzis, Pantelis Katharios, Emmanouil Flemetakis. Comparative Functional Genomic Analysis of Two Vibrio Phages Reveals Complex Metabolic Interactions with the Host Cell. Frontiers in Microbiology. 2016; 7 ():1807.
Chicago/Turabian StyleDimitrios Skliros; Panos G. Kalatzis; Pantelis Katharios; Emmanouil Flemetakis. 2016. "Comparative Functional Genomic Analysis of Two Vibrio Phages Reveals Complex Metabolic Interactions with the Host Cell." Frontiers in Microbiology 7, no. : 1807.
We combined transcriptomic and biochemical approaches to study rhizobial and plant sulfur (S) metabolism in nitrogen (N) fixing nodules (Fix+) of Lotus japonicus, as well as the link of S-metabolism to symbiotic nitrogen fixation and the effect of nodules on whole-plant S-partitioning and metabolism. Our data reveal that N-fixing nodules are thiol-rich organs. Their high adenosine 5′-phosphosulfate reductase activity and strong 35S-flux into cysteine and its metabolites, in combination with the transcriptional upregulation of several rhizobial and plant genes involved in S-assimilation, highlight the function of nodules as an important site of S-assimilation. The higher thiol content observed in nonsymbiotic organs of N-fixing plants in comparison to uninoculated plants could not be attributed to local biosynthesis, indicating that nodules are an important source of reduced S for the plant, which triggers whole-plant reprogramming of S-metabolism. Enhanced thiol biosynthesis in nodules and their impact on the whole-plant S-economy are dampened in plants nodulated by Fix− mutant rhizobia, which in most respects metabolically resemble uninoculated plants, indicating a strong interdependency between N-fixation and S-assimilation.
Chrysanthi Kalloniati; Panagiotis Krompas; Georgios Karalias; Michael Udvardi; Heinz Rennenberg; Cornelia Herschbach; Emmanouil Flemetakis. Nitrogen-Fixing Nodules Are an Important Source of Reduced Sulfur, Which Triggers Global Changes in Sulfur Metabolism in Lotus japonicus. The Plant Cell 2015, 27, 2384 -2400.
AMA StyleChrysanthi Kalloniati, Panagiotis Krompas, Georgios Karalias, Michael Udvardi, Heinz Rennenberg, Cornelia Herschbach, Emmanouil Flemetakis. Nitrogen-Fixing Nodules Are an Important Source of Reduced Sulfur, Which Triggers Global Changes in Sulfur Metabolism in Lotus japonicus. The Plant Cell. 2015; 27 (9):2384-2400.
Chicago/Turabian StyleChrysanthi Kalloniati; Panagiotis Krompas; Georgios Karalias; Michael Udvardi; Heinz Rennenberg; Cornelia Herschbach; Emmanouil Flemetakis. 2015. "Nitrogen-Fixing Nodules Are an Important Source of Reduced Sulfur, Which Triggers Global Changes in Sulfur Metabolism in Lotus japonicus." The Plant Cell 27, no. 9: 2384-2400.
The complex interaction between legumes and the family of soil bacteria known as rhizobia results in the formation of a novel plant organ, the root nodule. Inside nodules, bacteroids reduce molecular dinitrogen into ammonia. Both partners benefit from this symbiosis, since the plant’s requirements for nitrogen are fulfilled by the bacteroids, which in turn receive organic carbon from the plant originating from photosynthesis. The carbon cost for this process is high, rendering the nodules strong carbon sinks, as they are primarily dependent on the import and metabolism of sucrose to provide the energy and carbon skeletons required for atmospheric nitrogen reduction, the assimilation of the ammonia and the export of the resulting nitrogenous compounds. Thus it is not surprising that the availability of photoassimilates is found to be an important factor controlling nodule development and function. Although carbon metabolism during symbiotic nitrogen fixation has received significant attention since the early days of research on the legume–rhizobium symbiosis, the introduction of the model legumes Lotus japonicus and Medicago truncatula and the development of genomic resources for them and various crop legumes have allowed new insights into old questions about the biochemical and molecular mechanisms involved. These include sucrose and starch metabolism, dark-CO2 fixation and responses of carbohydrate metabolism to environmental factors and the availability of other nutrients.
Emmanouil Flemetakis; Trevor L. Wang. Carbon Metabolism During Symbiotic Nitrogen Fixation. Soil Biology 2013, 53 -68.
AMA StyleEmmanouil Flemetakis, Trevor L. Wang. Carbon Metabolism During Symbiotic Nitrogen Fixation. Soil Biology. 2013; ():53-68.
Chicago/Turabian StyleEmmanouil Flemetakis; Trevor L. Wang. 2013. "Carbon Metabolism During Symbiotic Nitrogen Fixation." Soil Biology , no. : 53-68.
MADS-box genes constitute a large family of transcription factors functioning as key regulators of many processes during plant vegetative and reproductive development. Type II MADS-box genes have been intensively investigated and are mostly involved in vegetative and flowering development. A growing number of studies of Type I MADS-box genes in Arabidopsis, have assigned crucial roles for these genes in gamete and seed development and have demonstrated that a number of Type I MADS-box genes are epigenetically regulated by DNA methylation and histone modifications. However, reports on agronomically important cereals such as barley and wheat are scarce.
Aliki Kapazoglou; Cawas Engineer; Vicky Drosou; Chrysanthi Kalloniati; Eleni Tani; Aphrodite Tsaballa; Evangelia D Kouri; Ioannis Ganopoulos; Emmanouil Flemetakis; Athanasios S Tsaftaris. The study of two barley Type I-like MADS-box genes as potential targets of epigenetic regulation during seed development. BMC Plant Biology 2012, 12, 166 -166.
AMA StyleAliki Kapazoglou, Cawas Engineer, Vicky Drosou, Chrysanthi Kalloniati, Eleni Tani, Aphrodite Tsaballa, Evangelia D Kouri, Ioannis Ganopoulos, Emmanouil Flemetakis, Athanasios S Tsaftaris. The study of two barley Type I-like MADS-box genes as potential targets of epigenetic regulation during seed development. BMC Plant Biology. 2012; 12 (1):166-166.
Chicago/Turabian StyleAliki Kapazoglou; Cawas Engineer; Vicky Drosou; Chrysanthi Kalloniati; Eleni Tani; Aphrodite Tsaballa; Evangelia D Kouri; Ioannis Ganopoulos; Emmanouil Flemetakis; Athanasios S Tsaftaris. 2012. "The study of two barley Type I-like MADS-box genes as potential targets of epigenetic regulation during seed development." BMC Plant Biology 12, no. 1: 166-166.
Extensive studies on the dry fruits of the model plant arabidopsis (Arabidopsis thaliana) have revealed various gene regulators of the development and dehiscence of the siliques. Peach pericarp is analogous to the valve tissues of the arabidopsis siliques. The stone (otherwise called pit) in drupes is formed through lignification of the fruit endocarp. The lignified endocarp in peach can be susceptible to split-pit formation under certain genetic as well as environmental factors. This phenomenon delays processing of the clingstone varieties of peach and causes economical losses for the peach fruit canning industry. The FRUITFULL (FUL) and SHATTERPROOF (SHP) genes are key MADS-box transcription protein coding factors that control fruit development and dehiscence in arabidopsis by promoting the expression of basic helix-loop-helix (bHLH) transcription factors like SPATULA (SPT) and ALCATRAZ (ALC). Results from our previous studies on peach suggested that temporal regulation of PPERFUL and PPERSHP gene expression may be involved in the regulation of endocarp margin development. In the present study a PPERSPATULA-like (PPERSPT) gene was cloned and characterized. Comparative analysis of temporal regulation of PPERSPT gene expression during pit hardening in a resistant and a susceptible to split-pit variety, suggests that this gene adds one more component to the genes network that controls endocarp margins development in peach. Taking into consideration that no ALC-like genes have been identified in any dicot plant species outside the Brassicaceae family, where arabidopsis belongs, PPERSPT may have additional role(s) in peach that are fulfilled in arabidopsis by ALC.
Eleni Tani; Aphrodite Tsaballa; Catalina Stedel; Chrissanthi Kalloniati; Dimitra Papaefthimiou; Alexios Polidoros; Nikos Darzentas; Ioannis Ganopoulos; Emmanouil Flemetakis; Panagiotis Katinakis; Athanasios Tsaftaris. The study of a SPATULA-like bHLH transcription factor expressed during peach (Prunus persica) fruit development. Plant Physiology and Biochemistry 2011, 49, 654 -663.
AMA StyleEleni Tani, Aphrodite Tsaballa, Catalina Stedel, Chrissanthi Kalloniati, Dimitra Papaefthimiou, Alexios Polidoros, Nikos Darzentas, Ioannis Ganopoulos, Emmanouil Flemetakis, Panagiotis Katinakis, Athanasios Tsaftaris. The study of a SPATULA-like bHLH transcription factor expressed during peach (Prunus persica) fruit development. Plant Physiology and Biochemistry. 2011; 49 (6):654-663.
Chicago/Turabian StyleEleni Tani; Aphrodite Tsaballa; Catalina Stedel; Chrissanthi Kalloniati; Dimitra Papaefthimiou; Alexios Polidoros; Nikos Darzentas; Ioannis Ganopoulos; Emmanouil Flemetakis; Panagiotis Katinakis; Athanasios Tsaftaris. 2011. "The study of a SPATULA-like bHLH transcription factor expressed during peach (Prunus persica) fruit development." Plant Physiology and Biochemistry 49, no. 6: 654-663.
Two cDNA clones coding for α-type carbonic anhydrases (CA; EC 4.2.1.1) in the nitrogen-fixing nodules of the model legume Lotus japonicus were identified. Functionality of the full-length proteins was confirmed by heterologous expression in Escherichia coli and purification of the encoded polypeptides. The developmental expression pattern of LjCAA1 and LjCAA2 revealed that both genes code for nodule enhanced carbonic anhydrase isoforms, which are induced early during nodule development. The genes were slightly to moderately down-regulated in ineffective nodules formed by mutant Mesorhizobium loti strains, indicating that these genes may also be involved in biochemical and physiological processes not directly linked to nitrogen fixation/assimilation. The spatial expression profiling revealed that both genes were expressed in nodule inner cortical cells, vascular bundles and central tissue. These results are discussed in the context of the possible roles of CA in nodule carbon dioxide (CO(2)) metabolism.
Daniela Tsikou; Catalina Stedel; Evangelia D. Kouri; Michael K. Udvardi; Trevor L. Wang; Panagiotis Katinakis; Nikolaos E. Labrou; Emmanouil Flemetakis. Characterization of two novel nodule-enhanced α-type carbonic anhydrases from Lotus japonicus. Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics 2011, 1814, 496 -504.
AMA StyleDaniela Tsikou, Catalina Stedel, Evangelia D. Kouri, Michael K. Udvardi, Trevor L. Wang, Panagiotis Katinakis, Nikolaos E. Labrou, Emmanouil Flemetakis. Characterization of two novel nodule-enhanced α-type carbonic anhydrases from Lotus japonicus. Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics. 2011; 1814 (4):496-504.
Chicago/Turabian StyleDaniela Tsikou; Catalina Stedel; Evangelia D. Kouri; Michael K. Udvardi; Trevor L. Wang; Panagiotis Katinakis; Nikolaos E. Labrou; Emmanouil Flemetakis. 2011. "Characterization of two novel nodule-enhanced α-type carbonic anhydrases from Lotus japonicus." Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics 1814, no. 4: 496-504.
International audiencePolyols are compounds that play various physiological roles in plants. Here we present the identification of four cDNA clones of the model legume Lotus japonicus, encoding proteins of the monosaccharide transporter-like (MST) superfamily that share significant homology with previously characterized polyol transporters (PLTs). One of the transporters, named LjPLT4, was characterized functionally after expression in yeast. Transport assays revealed that LjPLT4 is a xylitol-specific H(+)-symporter (K (m), 0.34 mM). In contrast to the previously characterized homologues, LjPLT4 was unable to transport other polyols, including mannitol, sorbitol, myo-inositol and galactitol, or any of the monosaccharides tested. Interestingly, some monosaccharides, including fructose and xylose, inhibited xylitol uptake, although no significant uptake of these compounds was detected in the LjPLT4 transformed yeast cells, suggesting interactions with the xylitol binding site. Subcellular localization of LjPLT4-eYFP fusions expressed in Arabidopsis leaf epidermal cells indicated that LjPLT4 is localized in the plasma membrane. Real-time RT-PCR revealed that LjPLT4 is expressed in all major plant organs, with maximum transcript accumulation in leaves correlating with maximum xylitol levels there, as determined by GC-MS. Thus, LjPLT4 is the first plasma membrane xylitol-specific H(+)-symporter to be characterized in plants
Katerina I. Kalliampakou; Evangelia D. Kouri; Haralabia Boleti; Ourania Pavli; Laurence Maurousset; Michael Udvardi; Panagiotis Katinakis; Rémi Lemoine; Emmanouil Flemetakis. Cloning and functional characterization of Lj PLT4, a plasma membrane xylitol H + - symporter from Lotus japonicus. Molecular Membrane Biology 2011, 28, 1 -13.
AMA StyleKaterina I. Kalliampakou, Evangelia D. Kouri, Haralabia Boleti, Ourania Pavli, Laurence Maurousset, Michael Udvardi, Panagiotis Katinakis, Rémi Lemoine, Emmanouil Flemetakis. Cloning and functional characterization of Lj PLT4, a plasma membrane xylitol H + - symporter from Lotus japonicus. Molecular Membrane Biology. 2011; 28 (1):1-13.
Chicago/Turabian StyleKaterina I. Kalliampakou; Evangelia D. Kouri; Haralabia Boleti; Ourania Pavli; Laurence Maurousset; Michael Udvardi; Panagiotis Katinakis; Rémi Lemoine; Emmanouil Flemetakis. 2011. "Cloning and functional characterization of Lj PLT4, a plasma membrane xylitol H + - symporter from Lotus japonicus." Molecular Membrane Biology 28, no. 1: 1-13.
We investigated the presence of carbonic anhydrase in root and hypocotyl of etiolated soybean using enzymatic, histochemical, immunohistochemical and in situ hybridization approaches. In parallel, we used in situ hybridization and immunolocaliza-tion to determine the expression pattern and localization of phosphoenolpyruvate carboxylase. Their co-localization in the root tip as well as in the central cylinder, suggests that a large fraction of the CO2 may be re-introduced into C4 compounds. GmPK3 expression, coding for a cytoplasmic isoform of pyruvate kinase, was detected in all different root cell types, suggesting that both phosphoenolpyruvate-utilizing enzymes are involved in phosphoenolpyruvate metabolism in etiolated soybean roots; a case indicative of the necessary flexibility plant metabolism has to adopt in order to compensate various physiological conditions.
Maria Dimou; Anca Paunescu; Georgios Aivalakis; Emmanouil Flemetakis; Panagiotis Katinakis. Co-localization of Carbonic Anhydrase and Phosphoenol-pyruvate Carboxylase and Localization of Pyruvate Kinase in Roots and Hypocotyls of Etiolated Glycine max Seedlings. International Journal of Molecular Sciences 2009, 10, 2896 -2910.
AMA StyleMaria Dimou, Anca Paunescu, Georgios Aivalakis, Emmanouil Flemetakis, Panagiotis Katinakis. Co-localization of Carbonic Anhydrase and Phosphoenol-pyruvate Carboxylase and Localization of Pyruvate Kinase in Roots and Hypocotyls of Etiolated Glycine max Seedlings. International Journal of Molecular Sciences. 2009; 10 (7):2896-2910.
Chicago/Turabian StyleMaria Dimou; Anca Paunescu; Georgios Aivalakis; Emmanouil Flemetakis; Panagiotis Katinakis. 2009. "Co-localization of Carbonic Anhydrase and Phosphoenol-pyruvate Carboxylase and Localization of Pyruvate Kinase in Roots and Hypocotyls of Etiolated Glycine max Seedlings." International Journal of Molecular Sciences 10, no. 7: 2896-2910.