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001-es BibID:	BIBFORM090165
Első szerző:	Nagy Gergely
Cím:	Effects of stressors on the macroorganisation of thylakoid membranes / Nagy Gergely, Zsiros Ottó, Ünnep Renáta, Paul Suman, Solymosi Katalin, Domokos-Szabolcsy Éva, Garab Győző
Dátum:	2019
Megjegyzések:	Thylakoid membranes, the site of oxygenic photosynthetic light reactions, in most photosynthetic organisms are organised into multilamellar membrane assemblies with remarkable structural and functional plasticity, associated with different regulatory mechanisms [1]. When the organisms are subjected to stress conditions, monitoring the nature and extent of stress-induced membrane reorganisations is a key step towards the understanding the mechanism of stress responses in vivo . In a series of experiments, we exposed different photosynthetic organisms to abiotic and biotic stresses and used small-angle neutron scattering (SANS) to reveal the stress-induced changes in the thylakoid membrane ultrastructures. SANS is a non-invasive technique, which has been demonstrated to be capable of providing statistically and spatially averaged structural information about the structure and structural flexibility of multilamellar membrane systems of different photosynthetic organisms [2,3]. Unicellular algae are highly sensitive to heavy-metal ions, such as cadmium and chromium. Cadmium is one of the most toxic aquatic contaminants. The inhibitory effects of Cd on both the dark and light reactions of photosynthesis have been studied in several laboratories [4,5]; however, a general model is yet to be formulated. Chromium is also highly toxic for photosynthetic organisms [6]; due to its extensive industrial use, large quantities of Cr compounds are present as pollutant in the environment. Here we report on the effects of these two heavy metal ions on the thylakoid membrane systems of the green alga Chlorella variabilis , at different concentrations and lengths of the treatments [7]. The trace element selenium, while being an essential nutrient for animals, also poses an environmental hazard at larger concentrations ? a duality that depends on multiple factors such as the chemical form and concentration of selenium [8]. While the influence of Se on photosynthesis is highly relevant to environmental pollution and soil remediation, the production of Se-rich crops is also of interest. Our investigations on cultured tobacco plantlets revealed adverse effects of different forms and concentrations of selenium, selenate and nano-Se, on the granum thylakoid membranes of young tobacco leaves [9]. We also studied the effects of strong illumination, a key biotic stress factor, on the rainforest vine Monstera deliciosa ? a plant which can survive both the low-light environment of the rainforest floor and the high-light environment on the sunlit canopy. We used this model plant, with giant grana and an outstanding capability for the photoprotective, ?pH-dependent non-photochemical quenching (NPQ), to study the hypothesized correlation between membrane reorganizations and NPQ. Our results revealed a close correlation between the time courses of NPQ and major reversible reorganizations in the periodic multilamellar organization of the grana in these leaves [10].
Tárgyszavak:	Természettudományok Biológiai tudományok előadáskivonat könyvrészlet
Megjelenés:	Abstracts ECNS 2019 : European conference of neutron scattering / Mikhail Kovalchuk. - p. 621.
További szerzők:	Zsíros Ottó Ünnep Renáta Suman, Paul Solymosi Katalin Domokos-Szabolcsy Éva (1978-) (molekuláris biológus) Garab Győző
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat
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