9 results on '"Kostas, S."'
Search Results
2. Investigation of Rosa species by an optimized LC-QTOF-MS/MS method using targeted and non-targeted screening strategies combined with multivariate chemometrics.
- Author
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Mitsikaris PD, Kostas S, Mourtzinos I, Menkissoglu-Spiroudi U, Papadopoulos A, and Kalogiouri NP
- Subjects
- Chromatography, Liquid methods, Multivariate Analysis, Chemometrics methods, Flowers chemistry, Rosa chemistry, Tandem Mass Spectrometry methods
- Abstract
Introduction: Plants of the Rosa genus are renowned for their pronounced and pleasant aroma and colors., Objective: The aim of this work was to develop a novel liquid chromatographic triple quadrupole time-of-flight tandem mass spectrometric (LC-QTOF-MS/MS) method for the investigation of the bioactive fingerprint of petals of different genotypes belonging to Rosa damascena and Rosa centifolia species., Methodology: Central composite design (CCD) of response surface methodology (RSM) was used for the optimization of the LC-QTOF-MS/MS method. The method was validated and target, suspect, and non-target screening workflows were applied. Statistical analysis and chemometric tools were utilized to explore the metabolic fingerprint of the Rosa species., Results: RSM revealed that the optimal extraction parameters involved mixing 11 mg of sample with 1 mL of MeOH:H
2 O (70:30, v/v). Target analysis confirmed the presence of 11 analytes, all of which demonstrated low limits of quantification (LOQs; as low as 0.048 ng mg-1 ) and sufficient recoveries (RE: 85%-107%). In total, 28 compounds were tentatively identified through suspect analysis. Non-target analysis enabled the generation of robust OPLS-DA and HCA models that classified the samples according to their species with 100% accuracy., Conclusions: A novel LC-QTOF-MS/MS method was developed and applied in the analysis of 47 R. centifolia and R. damascena flowers belonging to different genotypes., (© 2024 The Authors. Phytochemical Analysis published by John Wiley & Sons Ltd.)- Published
- 2024
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3. A metabolome and transcriptome survey to tap the dynamics of fruit prolonged shelf-life and improved quality within Greek tomato germplasm.
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Mellidou I, Koukounaras A, Frusciante S, Rambla JL, Patelou E, Ntoanidou S, Pons C, Kostas S, Nikoloudis K, Granell A, Diretto G, and Kanellis AK
- Abstract
Introduction: Tomato is a high economic value crop worldwide with recognized nutritional properties and diverse postharvest potential. Nowadays, there is an emerging awareness about the exploitation and utilization of underutilized traditional germplasm in modern breeding programs. In this context, the existing diversity among Greek accessions in terms of their postharvest life and nutritional value remains largely unexplored., Methods: Herein, a detailed evaluation of 130 tomato Greek accessions for postharvest and nutritional characteristics was performed, using metabolomics and transcriptomics, leading to the selection of accessions with these interesting traits., Results: The results showed remarkable differences among tomato Greek accessions for overall ripening parameters (color, firmness) and weight loss. On the basis of their postharvest performance, a balance between short shelf life (SSL) and long shelf life (LSL) accessions was revealed. Metabolome analysis performed on 14 selected accessions with contrasting shelf-life potential identified a total of 206 phytonutrients and volatile compounds. In turn, transcriptome analysis in fruits from the best SSL and the best LSL accessions revealed remarkable differences in the expression profiles of transcripts involved in key metabolic pathways related to fruit quality and postharvest potential., Discussion: The pathways towards cell wall synthesis, polyamine synthesis, ABA catabolism, and steroidal alkaloids synthesis were mostly induced in the LSL accession, whereas those related to ethylene biosynthesis, cell wall degradation, isoprenoids, phenylpropanoids, ascorbic acid and aroma ( TomloxC ) were stimulated in the SSL accession. Overall, these data would provide valuable insights into the molecular mechanism towards enhancing shelf-life and improving flavor and aroma of modern tomato cultivars., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The authors declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2023 Mellidou, Koukounaras, Frusciante, Rambla, Patelou, Ntoanidou, Pons, Kostas, Nikoloudis, Granell, Diretto and Kanellis.)
- Published
- 2023
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4. The role of endothelial shear stress, shear stress gradient, and plaque topography in plaque erosion.
- Author
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Hakim D, Pinilla-Echeverri N, Coskun AU, Pu Z, Kajander OA, Rupert D, Maynard C, Cefalo N, Siasos G, Papafaklis MI, Kostas S, Michalis LK, Jolly S, Mehta SR, Sheth T, Croce K, and Stone PH
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- Humans, Female, Endothelium, Vascular, Coronary Angiography, Heart, Coronary Vessels diagnostic imaging, Coronary Artery Disease diagnostic imaging, Plaque, Atherosclerotic
- Abstract
Background and Aims: Plaque erosion is a common underlying cause of acute coronary syndromes. The role of endothelial shear stress (ESS) and endothelial shear stress gradient (ESSG) in plaque erosion remains unknown. We aimed to determine the role of ESS metrics and maximum plaque slope steepness in plaques with erosion versus stable plaques., Methods: This analysis included 46 patients/plaques from TOTAL and COMPLETE trials and Brigham and Women's Hospital's database who underwent angiography and OCT. Plaques were divided into those with erosion (n = 24) and matched stable coronary plaques (n = 22). Angiographic views were used to generate a 3-D arterial reconstruction, with centerlines merged from angiography and OCT pullback. Local ESS metrics were assessed by computational fluid dynamics. Among plaque erosions, the up- and down-slope (Δ lumen area/frame) was calculated for each culprit plaque., Results: Compared with stable plaque controls, plaques with an erosion were associated with higher max ESS (8.3 ± 4.8 vs. 5.0 ± 1.9 Pa, p = 0.02) and max ESSG any direction (9.2 ± 7.5 vs. 4.3 ± 3.11 Pa/mm, p = 0.005). Proximal erosion was associated with a steeper plaque upslope while distal erosion with a steeper plaque downslope. Max ESS and Max ESSG any direction were independent factors in the development of plaque erosion (OR 1.32, 95%CI 1.06-1.65, p = 0.014; OR 1.22, 95% CI 1.03-1.45, p = 0.009, respectively)., Conclusions: In plaques with similar luminal stenosis, plaque erosion was strongly associated with higher ESS, ESS gradients, and plaque slope as compared with stable plaques. These data support that ESS and slope metrics play a key role in the development of plaque erosion and may help prognosticate individual plaques at risk for future erosion., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)
- Published
- 2023
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5. Effect of Temperature on Breaking of Morphophysiological Dormancy and Seed Germination Leading to Bulblet Production in Two Endemic Tulip Species from Greece.
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Pipinis E, Hatzilazarou S, Kostas S, Stagiopoulou R, Gitsa K, Dariotis E, Samartza I, Plastiras I, Kriemadi E, Bareka P, Lykas C, Tsoktouridis G, and Krigas N
- Abstract
Due to botanical tulips' economic interest coupled with limited information regarding their seed germination, we investigated the effect of temperature on dormancy release and germination in two endangered local endemic tulip species of Greece ( Tulipa hageri Heldr., T. orphanidea Heldr.). Their germination responses at five constant temperatures (5, 10, 15, 20, and 25 °C) were evaluated in growth chambers, while the type of seed dormancy and the temperature effect on its release were determined based on open-sourced, R-derived species-specific ecological profiles illustrating abiotic conditions of their wild habitats. The results indicated a range-specific temperature dependence in seed germination for both studied species with seed germination observed only in very low temperatures (5-10 °C). The seeds of both species after dispersal had an underdeveloped embryo. The existence of a complex morphophysiological seed dormancy was confirmed in both species by the significant embryo development only at 5 and 10 °C (almost doubled after 30 days) coupled with observed delay in germination only at low temperatures. Furthermore, to facilitate their cultivation and ex situ conservation, the germinated seeds were planted in pots to develop bulblets in greenhouse conditions resulting in bigger T. orphanidea bulblets compared to T. hageri .
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- 2023
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6. Influence of Temperature on Seed Germination of Five Wild-Growing Tulipa Species of Greece Associated with Their Ecological Profiles: Implications for Conservation and Cultivation.
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Hatzilazarou S, Pipinis E, Kostas S, Stagiopoulou R, Gitsa K, Dariotis E, Avramakis M, Samartza I, Plastiras I, Kriemadi E, Bareka P, Lykas C, Tsoktouridis G, and Krigas N
- Abstract
Although tulips are famous worldwide as ornamental plants, the knowledge about the seed germination of wild-growing species remains limited. The aim of the present study was to investigate the effect of temperature on seed germination of the local, wild-growing Greek endemics Tulipa bakeri and T. goulimyi and the sub-Balkan endemic T. undulatifolia , which are threatened with extinction, as well as the Mediterranean T. australis and the Asiatic T. clusiana naturalized on Chios Island (Greece). The germination responses at five constant temperatures (5, 10, 15, 20, and 25 °C) were assessed for all studied species in growth chambers under a 12:12 light-dark photoperiod. The ecological profile for each species was developed in R using open-source bioclimatic data; this was built to illustrate the abiotic environmental conditions of their wild habitats, to facilitate the examination of temperature effects on seed germination, and to facilitate their cultivation in artificial environments. The results indicated that the seed germination requirements of the studied species had a range-specific temperature dependence, reflecting their natural adaptation to local ecological conditions. Seed germination of T. bakeri , T. australis , and T. clusiana was observed only in a narrow range of very low temperatures (5-10 °C), whereas germination of T. undulatifolia and T. goulimyi occurred at temperatures between 5 and 15 °C. A temperature increase to 20 or 25 °C resulted in the absence of seed germination for all five Greek tulip species. The germinated seeds were planted in pots and bulblets were developed under greenhouse conditions. Seeds and bulblets constitute valuable genetic materials for the cultivation and ex situ conservation of these five Greek tulip species, three of which are threatened with extinction.
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- 2023
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7. Over-expression of GGP1 and GPP genes enhances ascorbate content and nutritional quality of tomato.
- Author
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Koukounaras A, Mellidou I, Patelou E, Kostas S, Shukla V, Engineer C, Papaefthimiou D, Amari F, Chatzopoulos D, Mattoo AK, and Kanellis AK
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- Ascorbic Acid chemistry, Ethylenes chemistry, Fruit chemistry, Gene Expression Regulation, Plant, Phosphates chemistry, Phosphoric Monoester Hydrolases genetics, Plant Breeding, Plants, Genetically Modified chemistry, Solanum lycopersicum chemistry, Solanum lycopersicum genetics, Nutritive Value
- Abstract
L-Ascorbic acid (AsA), a strong antioxidant, serves as an enzyme cofactor and redox status marker, modulating a plethora of biological processes. As tomato commercial varieties and hybrids possess relatively low amounts of AsA, the improvement of fruit AsA represents a strategic goal for enhanced human health. Previously, we have suggested that GDP-L-Galactose phosphorylase (GGP) and L-galactose-1-phosphate phosphatase (GPP) can serve as possible targets for AsA manipulation in tomato (Solanum lycopersicon L.) fruit. To this end, we produced and evaluated T3 transgenic tomato plants carrying these two genes under the control of CaMV-35S and two fruit specific promoters, PPC2 and PG-GGPI. The transgenic lines had elevated levels of AsA, with the PG-GGP1 line containing 3-fold more AsA than WT, without affecting fruit characteristics. Following RNA-Seq analysis, 164 and 13 DEGs were up- or down-regulated, respectively, between PG-GGP1 and WT pink fruits. PG-GGP1 fruit had a distinct number of up-regulated transcripts associated with cell wall modification, ethylene biosynthesis and signaling, pollen fertility and carotenoid metabolism. The elevated AsA accumulation resulted in the up regulation of AsA associated transcripts and alternative biosynthetic pathways suggesting that the entire metabolic pathway was influenced, probably via master regulation. We show here that AsA-fortification of tomato ripe fruit via GGP1 overexpression under the action of a fruit specific promoter PG affects fruit development and ripening, reduces ethylene production, and increased the levels of sugars, and carotenoids, supporting a robust database to further explore the role of AsA induced genes for agronomically important traits, breeding programs and precision gene editing approaches., Competing Interests: Declaration of competing interest The authors declare no competing interest., (Copyright © 2022 Elsevier Masson SAS. All rights reserved.)
- Published
- 2022
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8. DNA Barcoding, GIS-Facilitated Seed Germination and Pilot Cultivation of Teucrium luteum subsp. gabesianum (Lamiaceae), a Tunisian Local Endemic with Potential Medicinal and Ornamental Value.
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Kostas S, Hatzilazarou S, Pipinis E, Bourgou S, Ben Haj Jilani I, Ben Othman W, Megdiche-Ksouri W, Ghrabi-Gammar Z, Libiad M, Khabbach A, El Haissoufi M, Lamchouri F, Koundourakis E, Greveniotis V, Papaioannou E, Sakellariou MA, Anestis I, Tsoktouridis G, and Krigas N
- Abstract
In the context of plant conservation and sustainable use of unique neglected and underutilized phytogenetic resources, this study focused on the Tunisian local endemic Teucrium luteum subsp. gabesianum (Lamiaceae). Using Geographical Information Systems and online databases, detailed taxon-specific ecological profiling was produced for the first time, which illustrated the temperature and climate conditions in its wild habitats and facilitated the investigation of how temperature affects its seed germination, thus making its cultivation in anthropogenic environments possible. Following the seed propagation first reported herein (77.5−81.25% at temperatures between 15 and 25 °C), species-specific in situ and ex situ conservation efforts or sustainable exploitation strategies can be enabled. This study also reported for the first time how chemical and integrated nutrient management (INM) fertilizers affect the growth and pilot cultivation of its seedlings (INM more advantageous). The firstly-reported herein DNA barcoding may enable its traceability, allowing future product design. The multidisciplinary approach followed has paved the way to bridge important research gaps hindering conservation efforts and/or the sustainable exploitation of this local Tunisian endemic plant to date. Based on the aforementioned results, the feasibility and readiness timescale for its sustainable exploitation was overviewed and re-evaluated herein, upgrading (>two-fold) its potential value for the medicinal-cosmetic, agro-alimentary, and ornamental-horticultural sectors.
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- 2022
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9. GIS-Facilitated Seed Germination and Multifaceted Evaluation of the Endangered Abies marocana Trab. (Pinaceae) Enabling Conservation and Sustainable Exploitation.
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Hatzilazarou S, El Haissoufi M, Pipinis E, Kostas S, Libiad M, Khabbach A, Lamchouri F, Bourgou S, Megdiche-Ksouri W, Ghrabi-Gammar Z, Aslanidou V, Greveniotis V, Sakellariou MA, Anestis I, Tsoktouridis G, and Krigas N
- Abstract
In the frame of the sustainable use of neglected and underutilized phytogenetic resources, and along with numerous studies in Abies spp. due to the innate conservation value of fir forests, this research focused on the Moroccan endemic fir, Abies marocana. The aim was triple-fold: to assess its potential and dynamics in economic sectors for sustainable exploitation; to determine the ecological conditions in which the species naturally thrives; and to find the appropriate requirements for its successful seed germination. We sourced multifaceted evaluations for three economic sectors performed in three levels, using 48 attributes and eight criteria from previous studies of our own, and the relevant species-specific assessments are overviewed herein in detail. The species' ecological profile was constructed using Geographical Information Systems (GIS) and open access data (Worldclim). Seed germination trials were performed to examine the effect of cold stratification (non-stratified, one- and two-months stratified seeds), the influence of four temperatures (10 °C, 15 °C, 20 °C, and 25 °C), and interactions thereof in relation to germination percentage (GP) and mean germination time (MGT). The experiments showed that the interaction of cold stratification and germination temperature has a strong effect on the GP and MGT of A. marocana seeds. A detailed GIS-derived ecological profile of the focal species was created in terms of precipitation and temperature natural regimes, enabling the interpretation of the seed germination results. The multifaceted evaluations reveal an interesting potential of the Moroccan fir in different economic sectors, which is mainly compromised due to extant research gaps, unfavorable conditions, and low stakeholder attraction. The findings of this study fill in extant research gaps, contribute to in situ and ex situ conservation strategies, and can facilitate the sustainable exploitation of this emblematic local endemic plant of northern Morocco.
- Published
- 2021
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