A5045839900- Photosynthetic Processes and Mechanisms
- Spectroscopy and Quantum Chemical Studies
- Photoreceptor and optogenetics research
- Light effects on plants
- Algal biology and biofuel production
- Mitochondrial Function and Pathology
- Plant Stress Responses and Tolerance
- Photochemistry and Electron Transfer Studies
- Porphyrin and Phthalocyanine Chemistry
- Antioxidant Activity and Oxidative Stress
- Advanced Fluorescence Microscopy Techniques
- Plant nutrient uptake and metabolism
- Weed Control and Herbicide Applications
- Origins and Evolution of Life
- Marine and coastal ecosystems
- Advanced Electron Microscopy Techniques and Applications
- Advanced NMR Techniques and Applications
- Diatoms and Algae Research
- Protein Structure and Dynamics
- Plant and animal studies
- Plant Gene Expression Analysis
- Lipid Membrane Structure and Behavior
- Biocrusts and Microbial Ecology
- Quantum, superfluid, helium dynamics
- Plant responses to elevated CO2
HUN-REN Szegedi Biológiai Kutatóközpont
2015-2024
Institute of Plant Biology
2015-2024
Chinese Academy of Sciences
2024
University of Tartu
2024
Max Planck Institute for Chemical Energy Conversion
2024
Agricultural Institute
2023
Centre for Agricultural Research
2023
Hungarian Research Network
2023
Plant (United States)
2022
Hungarian Academy of Sciences
2010-2021
Abstract Photosystem II (PSII) uses solar energy to oxidize water and delivers electrons for life on Earth. The photochemical reaction center of PSII is known possess two stationary states. In the open state (PSIIO), absorption a single photon triggers electron-transfer steps, which convert into charge-separated closed (PSIIC). Here, by using steady-state time-resolved spectroscopic techniques Spinacia oleracea Thermosynechococcus vulcanus preparations, we show that additional illumination...
Time‐resolved fluorescence on oligomers of the main light‐harvesting complex from higher plants indicate that in vitro oligomerization leads to formation a weakly coupled inter‐trimer chlorophyll–chlorophyll (Chl) exciton state which converts tens ps into is spectrally broad and has strongly far‐red enhanced spectrum. Both its lifetime spectrum show striking similarity with 400 component appearing intact leaves Arabidopsis when non‐photochemical quenching (NPQ) induced. The components high...
The energy dissipation mechanism in oligomers of the major light-harvesting complex II (LHC II) from Arabidopsis thaliana mutants npq1 and npq2, zeaxanthin-deficient zeaxanthin-enriched, respectively, has been studied by femtosecond transient absorption. kinetics obtained at different excitation intensities are compared implications singlet-singlet annihilation discussed. Under conditions where is absent, two types LHC show distributive biexponential (bimodal) with lifetimes approximately...
Abstract Photosystem II (PSII) uses solar energy to oxidize water and delivers electrons fix CO2. Although the structure at atomic resolution basic photophysical photochemical functions of PSII are well understood, many important questions remain. The activity in vitro vivo is routinely monitored by recording induction kinetics chlorophyll a fluorescence (ChlF). According ‘mainstream’ model, rise from minimum level (Fo) maximum (Fm) ChlF dark-adapted reflects closure all functionally active...
Photosystem II (PSII) is an integral part of the photosynthesis machinery, in which several light-harvesting complexes rely on inter-complex excitonic energy transfer (EET) processes to channel reaction center. In this paper, we report a direct observation EET minimal PSII supercomplex from plants, containing trimeric complex (LHCII), monomeric CP26, and core complex. Using two-dimensional (2D) electronic spectroscopy, measure timescale 50 picoseconds for excitations LHCII-CP26 peripheral...
Abstract Nonradiative relaxation of high-energy excited states to the lowest state in chlorophylls marks first step process photosynthesis. We perform ultrafast transient absorption spectroscopy measurements, that reveal this internal conversion dynamics be slightly slower chlorophyll B than A . Modeling with non-adiabatic molecular simulations uncovers a critical role played by different side groups two molecules governing intramolecular redistribution wavefunction, leading, turn,...
The phycobilisomes function as the primary light-harvesting antennae in cyanobacteria and red algae, effectively harvesting transferring excitation energy to both photosystems. Here we investigate direct transfer route from photosystem I at room temperature a mutant of cyanobacterium
Abstract Using novel specially designed instrumentation, fluorescence emission spectra were recorded from Arabidopsis (Arabidopsis thaliana) leaves during the induction period of dark to high-light adaptation in order follow spectral changes associated with formation nonphotochemical quenching. In addition an overall decrease photosystem II (quenching) across entire spectrum, high light induced two specific relative spectra: (1) a main band at 682 nm far-red (750–760 nm) part spectrum (Δ...
We present here the first room-temperature 2D electronic spectroscopy study of energy transfer in plant light-harvesting complex II, LHCII.
Photosystem II (PSII) catalyses the photoinduced oxygen evolution and, by producing reducing equivalents drives, in concert with PSI, conversion of carbon dioxide to sugars. Our knowledge about architecture reaction centre (RC) complex and mechanisms charge separation stabilisation is well advanced. However, our understanding processes associated functioning RC incomplete: photochemical activity PSII routinely monitored chlorophyll-a fluorescence induction but presently available data are...
Abstract During photosynthesis, sunlight is efficiently captured by light-harvesting complexes, and the excitation energy then funneled towards reaction centre. These photosynthetic transfer (EET) pathways are complex proceed in a multistep fashion. Ultrafast two-dimensional electronic spectroscopy (2DES) an important tool to study EET processes complexes. However, can only be indirectly inferred correlating different cross peaks from series of 2DES spectra. Here we directly observe LHCII...
Chloroplast thylakoid membranes contain virtually all components of the energy-converting photosynthetic machinery. Their energized state, driving ATP synthesis, is enabled by bilayer organization membrane. However, their most abundant lipid species a non-bilayer-forming lipid, monogalactosyl-diacylglycerol; role polymorphism in these poorly understood. Earlier 31P-NMR experiments revealed coexistence and non-bilayer, isotropic phase spinach thylakoids. Packing molecules, tested fluorescence...
Abstract Photosynthetic antenna systems enable organisms harvesting light and transfer the energy to photosynthetic reaction centre, where conversion chemical takes place. One of most complex systems, chlorosome, found in green sulfur bacterium Chlorobaculum (Cba.) tepidum contains a baseplate, which is scaffolding super-structure, formed by protein CsmA bacteriochlorophyll . Here we present first high-resolution structure baseplate using intact fully functional, light-harvesting organelles...
Excess light causes damage to the photosynthetic apparatus of plants and algae primarily via reactive oxygen species. Singlet can be formed by interaction chlorophyll (Chl) triplet states, especially in Photosystem II reaction center, with oxygen. Whether Chls light-harvesting antenna complexes play direct role oxidative photodamage is less clear. In this work, light-induced photobleaching major trimeric complex (LHCII) investigated different molecular environments – protein aggregates,...
Photosystem I (PSI), found in all oxygenic photosynthetic organisms, uses solar energy to drive electron transport with nearly 100% quantum efficiency, thanks fast transfer among antenna chlorophylls and charge separation the reaction center. There is no complete consensus regarding kinetics of elementary steps involved overall trapping, especially rate primary separation. In this work, we employed two-dimensional coherent electronic spectroscopy follow dynamics a monomeric PSI complex from...