@article{MTMT:33921769,
	title = {Salinity stress provokes diverse physiological responses of eukaryotic unicellular microalgae},
	url = {https://m2.mtmt.hu/api/publication/33921769},
	author = {Farkas, Attila and Pap, Bernadett and Zsíros, Ottó and Patai, Roland and Shetty, Prateek and Garab, Győző and Bíró, Tibor and Ördög, Vince and Maróti, Gergely},
	doi = {10.1016/j.algal.2023.103155},
	journal-iso = {ALGAL RES},
	journal = {ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS},
	volume = {73},
	unique-id = {33921769},
	issn = {2211-9264},
	abstract = {Highly saline conditions represent a strong challenge for most microorganisms in freshwater ecosystems. Eukaryotic freshwater green algae from the Chlorophyta clade were investigated for their ability to survive in and adapt to increased salt concentration in the growth medium. Striking differences were detected between the responses of the various algae species to the elevated salt concentrations. The investigated Chlamydomonas reinhardtii cc124 and Coelastrella sp. MACC-549 algae showed a moderate resistance to increased salt concentration, while Chlorella sp. MACC-360 exhibited high salt tolerance, showed unaltered growth characteristics and photosynthetic efficiency compared to the saline-free control conditions even at 600 mM NaCl concentration. Diverse physiological responses to elevated salt concentrations were described for the tested algae including variations in their growth capacity, characteristic morphological changes, alterations in the structure and function of the photosynthetic machinery and differences in the production of reactive oxygen species. Special alterations were identified in the lipid and exopolysaccharide production patterns of the tested algal strains in response to high salinity. As a conclusion Chlorella sp. MACC-360 algae showed outstanding salt tolerance features. Together with the concomitant lipid-producing phenotype under highly saline conditions this unicellular green alga is a promising candidate for biotechnological applications.},
	keywords = {PHOTOSYNTHESIS; lipid; SALINITY; green algae; CHLORELLA; Chlamydomonas; Salt stress tolerance},
	year = {2023},
	eissn = {2211-9264},
	orcid-numbers = {Bíró, Tibor/0000-0002-5553-9850; Maróti, Gergely/0000-0002-3705-0461}
}

@article{MTMT:33117892,
	title = {Structural Entities Associated with Different Lipid Phases of Plant Thylakoid Membranes-Selective Susceptibilities to Different Lipases and Proteases},
	url = {https://m2.mtmt.hu/api/publication/33117892},
	author = {Dlouhy, Ondrej and Karlicky, Vaclav and Javornik, Uros and Kurasova, Irena and Zsíros, Ottó and Sket, Primoz and Kanna, Sai Divya and Böde, Kinga and Vecerova, Kristyna and Urban, Otmar and Gasanoff, Edward S. and Plavec, Janez and Spunda, Vladimir and Ughy, Bettina and Garab, Győző},
	doi = {10.3390/cells11172681},
	journal-iso = {CELLS-BASEL},
	journal = {CELLS},
	volume = {11},
	unique-id = {33117892},
	abstract = {It is well established that plant thylakoid membranes (TMs), in addition to a bilayer, contain two isotropic lipid phases and an inverted hexagonal (H-II) phase. To elucidate the origin of non-bilayer lipid phases, we recorded the P-31-NMR spectra of isolated spinach plastoglobuli and TMs and tested their susceptibilities to lipases and proteases; the structural and functional characteristics of TMs were monitored using biophysical techniques and CN-PAGE. Phospholipase-A1 gradually destroyed all P-31-NMR-detectable lipid phases of isolated TMs, but the weak signal of isolated plastoglobuli was not affected. Parallel with the destabilization of their lamellar phase, TMs lost their impermeability; other effects, mainly on Photosystem-II, lagged behind the destruction of the original phases. Wheat-germ lipase selectively eliminated the isotropic phases but exerted little or no effect on the structural and functional parameters of TMs-indicating that the isotropic phases are located outside the protein-rich regions and might be involved in membrane fusion. Trypsin and Proteinase K selectively suppressed the H-II phase-suggesting that a large fraction of TM lipids encapsulate stroma-side proteins or polypeptides. We conclude that-in line with the Dynamic Exchange Model-the non-bilayer lipid phases of TMs are found in subdomains separated from but interconnected with the bilayer accommodating the main components of the photosynthetic machinery.},
	keywords = {BEHAVIOR; PROTEIN; CYTOCHROME-C; DYNAMICS; PHOTOSYSTEM-II; TEMPERATURE-DEPENDENCE; THERMAL-STABILITY; Membrane Fusion; Plastoglobuli; NONBILAYER LIPIDS; Membrane models; FLUID-MOSAIC MODEL; Lipocalins; lipid polymorphism; non-bilayer lipids; P-31-NMR spectroscopy; structural and functional plasticity},
	year = {2022},
	eissn = {2073-4409},
	orcid-numbers = {Plavec, Janez/0000-0003-1570-8602}
}

@article{MTMT:32823174,
	title = {Salt Stress Induces Paramylon Accumulation and Fine-Tuning of the Macro-Organization of Thylakoid Membranes in Euglena gracilis Cells},
	url = {https://m2.mtmt.hu/api/publication/32823174},
	author = {Kanna, Sai Divya and Racskóné Domonkos, Ildikó and Kóbori, T.O. and Dergez, Ágnes Karolina and Böde, Kinga and Nagyapáti, Sarolta and Zsíros, Ottó and Ünnep, Renáta and Nagy, Gergely and Garab, Győző and Szilák, László and Solymosi, Katalin and Kovács, László and Ughy, Bettina},
	doi = {10.3389/fpls.2021.725699},
	journal-iso = {FRONT PLANT SCI},
	journal = {FRONTIERS IN PLANT SCIENCE},
	volume = {12},
	unique-id = {32823174},
	issn = {1664-462X},
	year = {2021},
	eissn = {1664-462X},
	orcid-numbers = {Solymosi, Katalin/0000-0001-5246-2547}
}

@article{MTMT:32293664,
	title = {Lipid Polymorphism of the Subchloroplast-Granum and Stroma Thylakoid Membrane-Particles. I. P-31-NMR Spectroscopy},
	url = {https://m2.mtmt.hu/api/publication/32293664},
	author = {Dlouhy, Ondrej and Javornik, Uros and Zsíros, Ottó and Sket, Primoz and Karlicky, Vaclav and Spunda, Vladimir and Plavec, Janez and Garab, Győző},
	doi = {10.3390/cells10092354},
	journal-iso = {CELLS-BASEL},
	journal = {CELLS},
	volume = {10},
	unique-id = {32293664},
	abstract = {Build-up of the energized state of thylakoid membranes and the synthesis of ATP are warranted by organizing their bulk lipids into a bilayer. However, the major lipid species of these membranes, monogalactosyldiacylglycerol, is a non-bilayer lipid. It has also been documented that fully functional thylakoid membranes, in addition to the bilayer, contain an inverted hexagonal (H-II) phase and two isotropic phases. To shed light on the origin of these non-lamellar phases, we performed P-31-NMR spectroscopy experiments on sub-chloroplast particles of spinach: stacked, granum and unstacked, stroma thylakoid membranes. These membranes exhibited similar lipid polymorphism as the whole thylakoids. Saturation transfer experiments, applying saturating pulses at characteristic frequencies at 5 degrees C, provided evidence for distinct lipid phases-with component spectra very similar to those derived from mathematical deconvolution of the P-31-NMR spectra. Wheat-germ lipase treatment of samples selectively eliminated the phases exhibiting sharp isotropic peaks, suggesting easier accessibility of these lipids compared to the bilayer and the H-II phases. Gradually increasing lipid exchanges were observed between the bilayer and the two isotropic phases upon gradually elevating the temperature from 5 to 35 degrees C, suggesting close connections between these lipid phases. Data concerning the identity and structural and functional roles of different lipid phases will be presented in the accompanying paper.},
	keywords = {THYLAKOID MEMBRANES; Isotropic phase; bilayer membrane; Grana; H-II phase; P-31-NMR; Non-lamellar lipid phases; DEM-dynamic exchange model; non-bilayer lipids},
	year = {2021},
	eissn = {2073-4409},
	orcid-numbers = {Plavec, Janez/0000-0003-1570-8602}
}

@article{MTMT:32258462,
	title = {Lipid Polymorphism of the Subchloroplast—Granum and Stroma Thylakoid Membrane–Particles. II. Structure and Functions},
	url = {https://m2.mtmt.hu/api/publication/32258462},
	author = {Dlouhý, Ondřej and Karlický, Václav and Arshad, Rameez and Zsíros, Ottó and Racskóné Domonkos, Ildikó and Kurasová, Irena and Wacha, András Ferenc and Morosinotto, Tomas and Bóta, Attila and Kouřil, Roman and Špunda, Vladimír and Garab, Győző},
	doi = {10.3390/cells10092363},
	journal-iso = {CELLS-BASEL},
	journal = {CELLS},
	volume = {10},
	unique-id = {32258462},
	abstract = {In Part I, by using P-31-NMR spectroscopy, we have shown that isolated granum and stroma thylakoid membranes (TMs), in addition to the bilayer, display two isotropic phases and an inverted hexagonal (H-II) phase; saturation transfer experiments and selective effects of lipase and thermal treatments have shown that these phases arise from distinct, yet interconnectable structural entities. To obtain information on the functional roles and origin of the different lipid phases, here we performed spectroscopic measurements and inspected the ultrastructure of these TM fragments. Circular dichroism, 77 K fluorescence emission spectroscopy, and variable chlorophyll-a fluorescence measurements revealed only minor lipase- or thermally induced changes in the photosynthetic machinery. Electrochromic absorbance transients showed that the TM fragments were re-sealed, and the vesicles largely retained their impermeabilities after lipase treatments-in line with the low susceptibility of the bilayer against the same treatment, as reflected by our P-31-NMR spectroscopy. Signatures of H-II-phase could not be discerned with small-angle X-ray scattering-but traces of H-II structures, without long-range order, were found by freeze-fracture electron microscopy (FF-EM) and cryo-electron tomography (CET). EM and CET images also revealed the presence of small vesicles and fusion of membrane particles, which might account for one of the isotropic phases. Interaction of VDE (violaxanthin de-epoxidase, detected by Western blot technique in both membrane fragments) with TM lipids might account for the other isotropic phase. In general, non-bilayer lipids are proposed to play role in the self-assembly of the highly organized yet dynamic TM network in chloroplasts.},
	year = {2021},
	eissn = {2073-4409},
	orcid-numbers = {Dlouhý, Ondřej/0000-0002-0694-928X; Karlický, Václav/0000-0002-7079-3160; Arshad, Rameez/0000-0001-9589-3312; Wacha, András Ferenc/0000-0002-9609-0893; Morosinotto, Tomas/0000-0002-0803-7591; Kouřil, Roman/0000-0001-8211-3348; Špunda, Vladimír/0000-0002-4467-1442}
}

@article{MTMT:31614001,
	title = {Thylakoid membrane reorganizations revealed by small-angle neutron scattering of Monstera deliciosa leaves associated with non-photochemical quenching},
	url = {https://m2.mtmt.hu/api/publication/31614001},
	author = {Ünnep, Renáta and Paul, S. and Zsíros, Ottó and Kovács, László and Székely, Noémi Kinga and Steinbach, Gábor and Appavou, M.-S. and Porcar, L. and Holzwarth, A.R. and Garab, Győző and Nagy, Gergely},
	doi = {10.1098/rsob.200144},
	journal-iso = {OPEN BIOL},
	journal = {OPEN BIOLOGY},
	volume = {10},
	unique-id = {31614001},
	abstract = {Non-photochemical quenching (NPQ) is an important photoprotective mechanism in plants and algae. Although the process is extensively studied, little is known about its relationship with ultrastructural changes of the thylakoid membranes. In order to better understand this relationship, we studied the effects of illumination on the organization of thylakoid membranes in Monstera deliciosa leaves. This evergreen species is known to exhibit very large NPQ and to possess giant grana with dozens of stacked thylakoids. It is thus ideally suited for small-angle neutron scattering measurements (SANS) - a non-invasive technique, which is capable of providing spatially and statistically averaged information on the periodicity of the thylakoid membranes and their rapid reorganizations in vivo. We show that NPQ-inducing illumination causes a strong decrease in the periodic order of granum thylakoid membranes. Development of NPQ and light-induced ultrastructural changes, as well as the relaxation processes, follow similar kinetic patterns. Surprisingly, whereas NPQ is suppressed by diuron, it impedes only the relaxation of the structural changes and not its formation, suggesting that structural changes do not cause but enable NPQ. We also demonstrate that the diminishment of SANS peak does not originate from light-induced redistribution and reorientation of chloroplasts inside the cells. © 2020 The Authors.},
	year = {2020},
	eissn = {2046-2441},
	orcid-numbers = {Steinbach, Gábor/0000-0001-7137-7030}
}

@article{MTMT:31605569,
	title = {Role of Protein-Water Interface in the Stacking Interactions of Granum Thylakoid Membranes-As Revealed by the Effects of Hofmeister Salts},
	url = {https://m2.mtmt.hu/api/publication/31605569},
	author = {Zsíros, Ottó and Ünnep, Renáta and Nagy, Gergely and Almásy, László and Patai, Roland and Szekely, NK and Kohlbrecher, J and Garab, Győző and Dér, András and Kovács, László},
	doi = {10.3389/fpls.2020.01257},
	journal-iso = {FRONT PLANT SCI},
	journal = {FRONTIERS IN PLANT SCIENCE},
	volume = {11},
	unique-id = {31605569},
	issn = {1664-462X},
	year = {2020},
	eissn = {1664-462X}
}

@article{MTMT:31395462,
	title = {Similarities and Differences in the Effects of Toxic Concentrations of Cadmium and Chromium on the Structure and Functions of Thylakoid Membranes in Chlorella variabilis},
	url = {https://m2.mtmt.hu/api/publication/31395462},
	author = {Zsíros, Ottó and Nagy, Gergely and Patai, Roland and Solymosi, Katalin and Gasser, U. and Polgár, Tamás Ferenc and Garab, Győző and Kovács, László and Hörcsik, Tibor Zsolt},
	doi = {10.3389/fpls.2020.01006},
	journal-iso = {FRONT PLANT SCI},
	journal = {FRONTIERS IN PLANT SCIENCE},
	volume = {11},
	unique-id = {31395462},
	issn = {1664-462X},
	year = {2020},
	eissn = {1664-462X},
	orcid-numbers = {Solymosi, Katalin/0000-0001-5246-2547}
}

@article{MTMT:30619359,
	title = {Lipid-polymorphism of plant thylakoid membranes. Enhanced non-bilayer lipid phases associated with increased membrane permeability.},
	url = {https://m2.mtmt.hu/api/publication/30619359},
	author = {Ughy, Bettina and Karlický, Václav and Dlouhý, Ondřej and Javornik, Uroš and Materová, Zuzana and Zsíros, Ottó and Šket, Primož and Plavec, Janez and Špunda, Vladimír and Garab, Győző},
	doi = {10.1111/ppl.12929},
	journal-iso = {PHYSIOL PLANTARUM},
	journal = {PHYSIOLOGIA PLANTARUM},
	volume = {166},
	unique-id = {30619359},
	issn = {0031-9317},
	abstract = {Earlier experiments, using 31 P-NMR and time-resolved merocyanine fluorescence spectroscopy, have shown that isolated intact, fully functional plant thylakoid membranes, in addition to the bilayer phase, contain three non-bilayer (or non-lamellar) lipid phases. It has also been shown that the lipid polymorphism of thylakoid membranes can be characterized by remarkable plasticity, i.e. by significant variations in 31 P-NMR signatures. However, changes in the lipid-phase behaviour of thylakoids could not be assigned to changes in the overall membrane organization and the photosynthetic activity, as tested by circular dichroism and 77 K fluorescence emission spectroscopy and the magnitude of the variable fluorescence of photosystem II, which all showed only marginal variations. In this work, we investigated in more detail the temporal stability of the different lipid phases by recording 31 P-NMR spectra on isolated thylakoid membranes that were suspended in sorbitol- or NaCl-based media. We observed, at 5°C during 8 h in the dark, substantial gradual enhancement of the isotropic lipid phases and diminishment of the bilayer phase in the sorbitol-based medium. These changes compared well with the gradually increasing membrane permeability, as testified by the gradual acceleration of the decay of flash-induced electrochromic absorption changes and characteristic changes in the kinetics of fast chlorophyll a-fluorescence transients; all variations were much less pronounced in the NaCl-based medium. These observations suggest that non-bilayer lipids and non-lamellar lipid phases play significant roles in the structural dynamics and functional plasticity of thylakoid membranes.},
	year = {2019},
	eissn = {1399-3054},
	pages = {278-287}
}

@article{MTMT:30509141,
	title = {Anisotropic Circular Dichroism of Light-Harvesting Complex II in Oriented Lipid Bilayers: Theory Meets Experiment},
	url = {https://m2.mtmt.hu/api/publication/30509141},
	author = {Akhtar, Parveen and Lindorfer, Dominik and Lingvay, Mónika and Pawlak, Krzyszof and Zsíros, Ottó and Siligardi, Giuliano and Javorfi, Tamas and Dorogi, Márta and Ughy, Bettina and Garab, Győző and Renger, Thomas and Lambrev, Petar},
	doi = {10.1021/acs.jpcb.8b12474},
	journal-iso = {J PHYS CHEM B},
	journal = {JOURNAL OF PHYSICAL CHEMISTRY B},
	volume = {123},
	unique-id = {30509141},
	issn = {1520-6106},
	abstract = {Anisotropic circular dichroism (ACD) spectroscopy of macroscopically aligned molecules reveals additional information about their excited states that is lost in the CD of randomly oriented solutions. ACD spectra of light-harvesting complex II (LHCII)-the main peripheral antenna of photosystem II in plants-in oriented lipid bilayers were recorded from the far-UV to the visible wavelength region. ACD spectra show a drastically enhanced magnitude and level of detail compared to the isotropic CD spectra, resolving a greater number of bands and weak optical transitions. Exciton calculations show that the spectral features in the chlorophyll Q y region are well-reproduced by an existing Hamiltonian for LHCII, providing further evidence for the identity of energy sinks at chlorophylls a603 and a610 in the stromal layer and chlorophylls a604 and a613 in the lumina] layer. We propose ACD spectroscopy to be a valuable tool linking the three-dimensional structure and the photophysical properties of pigment-protein complexes.},
	year = {2019},
	eissn = {1520-5207},
	pages = {1090-1098},
	orcid-numbers = {Akhtar, Parveen/0000-0002-3264-7154; Lingvay, Mónika/0000-0001-6725-6279}
}