TY - JOUR AU - Zavřel, Tomáš AU - Segečová, Anna AU - Kovács, László AU - Lukeš, Martin AU - Novák, Zoltán AU - Pohland, Anne-Christin AU - Szabó, Milán AU - Somogyi, Boglárka AU - Prášil, Ondřej AU - Červený, Jan AU - Bernát, Gábor TI - A Comprehensive Study of Light Quality Acclimation in Synechocystis Sp. PCC 6803 JF - PLANT AND CELL PHYSIOLOGY J2 - PLANT CELL PHYSIOL VL - 65 PY - 2024 IS - 8 SP - 1285 EP - 1297 PG - 13 SN - 0032-0781 DO - 10.1093/pcp/pcae062 UR - https://m2.mtmt.hu/api/publication/35082092 ID - 35082092 N1 - Funding Agency and Grant Number: Ministry of Education, Youth and Sports of CR [LM2018123, CZ.02.1.01/0.0/0.0/16_026/0008413, LUAUS24131]; National Research, Development and Innovation Office of Hungary [K 140351, RRF-2.3.1-21-2022-00014] Funding text: The Ministry of Education, Youth and Sports of CR (LM2018123; CZ.02.1.01/0.0/0.0/16_026/0008413; LUAUS24131) and the National Research, Development and Innovation Office of Hungary, NKFIH (K 140351 and RRF-2.3.1-21-2022-00014). AB - Cyanobacteria play a key role in primary production in both oceans and fresh waters and hold great potential for sustainable production of a large number of commodities. During their life, cyanobacteria cells need to acclimate to a multitude of challenges, including shifts in intensity and quality of incident light. Despite our increasing understanding of metabolic regulation under various light regimes, detailed insight into fitness advantages and limitations under shifting light quality remains underexplored. Here, we study photo-physiological acclimation in the cyanobacterium Synechocystis sp. PCC 6803 throughout the photosynthetically active radiation (PAR) range. Using light emitting diodes (LEDs) with qualitatively different narrow spectra, we describe wavelength dependence of light capture, electron transport and energy transduction to main cellular pools. In addition, we describe processes that fine-tune light capture, such as state transitions, or the efficiency of energy transfer from phycobilisomes to photosystems (PS). We show that growth was the most limited under blue light due to inefficient light harvesting, and that many cellular processes are tightly linked to the redox state of the plastoquinone (PQ) pool, which was the most reduced under red light. The PSI-to-PSII ratio was low under blue photons, however, it was not the main growth-limiting factor, since it was even more reduced under violet and near far-red lights, where Synechocystis grew faster compared to blue light. Our results provide insight into the spectral dependence of phototrophic growth and can provide the foundation for future studies of molecular mechanisms underlying light acclimation in cyanobacteria, leading to light optimization in controlled cultivations. LA - English DB - MTMT ER - TY - JOUR AU - Patil, Priyanka Pradeep AU - Nagy, Krisztina AU - Ábrahám, Ágnes AU - Vass, Imre AU - Szabó, Milán TI - Monitoring the photosynthetic activity at single-cell level in Haematococcus lacustris JF - PHOTOSYNTHETICA J2 - PHOTOSYNTHETICA VL - 61 PY - 2023 IS - SI SP - 473 EP - 482 PG - 10 SN - 0300-3604 DO - 10.32615/ps.2023.042 UR - https://m2.mtmt.hu/api/publication/34473960 ID - 34473960 N1 - Funding Agency and Grant Number: National Research, Development, and Innovation Office [NKFIH FK 128977]; [GINOP-2.3.2-15-2016-00026] Funding text: This work was supported by the National Research, Development, and Innovation Office (grant NKFIH FK 128977) and the grant GINOP-2.3.2-15-2016-00026. We thank Dr. Peter Galajda (BRC, Szeged) for fruitful discussions and for providing the microfluidic infrastructure. AB - Haematococcus lacustris is an important species of green algae because it produces the high-value carotenoid astaxanthin. Astaxanthin production is enhanced by various stress conditions causing the transformation of green vegetative cells to red cells with high amounts of astaxanthin, which plays various photoprotective and antioxidant roles. Although intensive research has been conducted to reveal the regulation of astaxanthin production, the photosynthetic capacity of the various cell forms is unresolved at the single-cell level. In this work, we characterized the photosynthetic and morphological changes of Haematococcus cells, using a combination of microfluidic tools and microscopic chlorophyll fluorescence imaging. We found marked but reversible changes in the variable chlorophyll fluorescence signatures upon the transformation of green cells to red cells, and we propose that the photosynthetic activity as revealed by single-cell chlorophyll fluorescence kinetics serves as a useful phenotypic marker of the different cell forms of Haematococcus. LA - English DB - MTMT ER - TY - JOUR AU - Mohammad Aslam, Sabit AU - Vass, Imre AU - Szabó, Milán TI - Characterization of the Flash-Induced Fluorescence Wave Phenomenon in the Coral Endosymbiont Algae, Symbiodiniaceae JF - INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES J2 - INT J MOL SCI VL - 24 PY - 2023 IS - 10 PG - 14 SN - 1661-6596 DO - 10.3390/ijms24108712 UR - https://m2.mtmt.hu/api/publication/34043896 ID - 34043896 N1 - Funding Agency and Grant Number: National Research, Development and Innovation Office (NKFIH) [FK128977]; Biological Research Centre, Szeged, Hungary Funding text: This research was funded by The National Research, Development and Innovation Office (NKFIH), grant number FK128977, and the APC was funded by Biological Research Centre, Szeged, Hungary. AB - The dinoflagellate algae, Symbiodiniaceae, are significant symbiotic partners of corals due to their photosynthetic capacity. The photosynthetic processes of the microalgae consist of linear electron transport, which provides the energetic balance of ATP and NADPH production for CO2 fixation, and alternative electron transport pathways, including cyclic electron flow, which ensures the elevated ATP requirements under stress conditions. Flash-induced chlorophyll fluorescence relaxation is a non-invasive tool to assess the various electron transport pathways. A special case of fluorescence relaxation, the so-called wave phenomenon, was found to be associated with the activity of NAD(P)H dehydrogenase (NDH) in microalgae. We showed previously that the wave phenomenon existed in Symbiodiniaceae under acute heat stress and microaerobic conditions, however, the electron transport processes related to the wave phenomenon remained unknown. In this work, using various inhibitors, we show that (i) the linear electron transport has a crucial role in the formation of the wave, (ii) the inhibition of the donor side of Photosystem II did not induce the wave, whereas inhibition of the Calvin-Benson cycle accelerated it, (iii) the wave phenomenon was related to the operation of type II NDH (NDH-2). We therefore propose that the wave phenomenon is an important marker of the regulation of electron transport in Symbiodiniaceae. LA - English DB - MTMT ER - TY - JOUR AU - Bates, Harvey AU - Zavafer, Alonso AU - Szabó, Milán AU - Ralph, Peter J. TI - The slow-phase of chlorophyll fluorescence induction curve reflects the electron transport rates of Photosystem II in vivo in Chlorella vulgaris JF - JOURNAL OF APPLIED PHYCOLOGY J2 - J APPL PHYCOL VL - 35 PY - 2023 IS - 1 SP - 109 EP - 116 PG - 8 SN - 0921-8971 DO - 10.1007/s10811-022-02890-0 UR - https://m2.mtmt.hu/api/publication/33608945 ID - 33608945 N1 - Export Date: 12 April 2023 CODEN: JAPPE AB - Ideally methods and parameters to assess photosynthesis in the microalga Chlorella vulgaris must be rapid, non-invasive, accurate, and simple to implement. Methods such as the Quantum Yield of photosynthesis (phi(Po) or F-v/F-m) yield rapid results but do not reflect the actual electron turnover of PSII (ETRII). Alternatively, methods that calculate ETRII take several minutes to execute, require expensive instrumentation, and manual input. In this work, we describe a method to estimate ETRII in real-time via predictive statistic modelling. This method utilises the Kautsky induction curve and a low-cost chlorophyll a fluorometer. Our model optimises the fit of linear regressions between the normalized fluorescence intensity after F-m (named S-ETR) and ETRII measurements using traditional methods. This allows for an estimation of ETRII in real-time through Kautsky induction curves alone. S-ETR can then be used as a faster alternative to quenching analysis to determine bioenergetics performance during steady state and can be assessed with any chlorophyll fluorometer capable of measuring the Kautsky induction curve. The S-ETR parameter allows for a high-throughput and high-resolution assessment of photosynthesis while being non-invasive, having lower production costs, and with lower technical requirements. Furthermore, the biophysical bases of the method are discussed. LA - English DB - MTMT ER - TY - JOUR AU - Mohammad Aslam, Sabit AU - Patil, Priyanka Pradeep AU - Vass, Imre AU - Szabó, Milán TI - Heat-Induced Photosynthetic Responses of Symbiodiniaceae Revealed by Flash-Induced Fluorescence Relaxation Kinetics JF - FRONTIERS IN MARINE SCIENCE J2 - FRONT MAR SCI VL - 9 PY - 2022 SN - 2296-7745 DO - 10.3389/fmars.2022.932355 UR - https://m2.mtmt.hu/api/publication/33025641 ID - 33025641 N1 - Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary Doctoral School of Biology, University of Szeged, Szeged, Hungary Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia Export Date: 15 August 2022 Correspondence Address: Vass, I.; Institute of Plant Biology, Hungary; email: vass.imre@brc.hu Correspondence Address: Szabó, M.; Institute of Plant Biology, Hungary; email: szabo.milan@brc.hu LA - English DB - MTMT ER - TY - JOUR AU - Bashir, Faiza AU - Kovács, Sándor AU - Ábrahám, Ágnes AU - Nagy, Krisztina AU - Ayaydin, Ferhan AU - Kelemen-Valkony, Ildikó AU - Ferenc, Györgyi AU - Galajda, Péter AU - Tóth, Szilvia Zita AU - Sass, László AU - Kós, Péter AU - Vass, Imre AU - Szabó, Milán TI - Viable protoplast formation of the coral endosymbiont alga Symbiodinium spp. in a microfluidics platform JF - LAB ON A CHIP J2 - LAB CHIP VL - 22 PY - 2022 IS - 16 SP - 2986 EP - 2999 PG - 14 SN - 1473-0197 DO - 10.1039/D2LC00130F UR - https://m2.mtmt.hu/api/publication/32832922 ID - 32832922 N1 - Funding Agency and Grant Number: Hungarian Academy of Sciences, MTA Premium Postdoctoral Research Program [GINOP-2.3.2-15-2016-00026, PREMIUM-2017-38]; National Research, Development and Innovation Office [NKFIH FK 128977, NKFIH K 116016, NKFIH K 116526, NKFIH PD 124889]; Janos Bolyai Research Scholarship of the Hungarian Academy of Sciences [BO/00463/18/8] Funding text: This work was supported by the grants GINOP-2.3.2-15-2016-00026, Hungarian Academy of Sciences, MTA Premium Postdoctoral Research Program PREMIUM-2017-38 (awarded to M. S.), National Research, Development and Innovation Office grant number NKFIH FK 128977 (awarded to M. S.), NKFIH K 116016, NKFIH K 116526 (awarded to P. G.), and NKFIH PD 124889 (awarded to K. N.) K. N. was supported by the Janos Bolyai Research Scholarship of the Hungarian Academy of Sciences (BO/00463/18/8). The authors thank Laszlo Der for valuable discussions and his help with the model calculations. AB - Symbiodiniaceae is an important dinoflagellate family which lives in endosymbiosis with reef invertebrates, including coral polyps, making them central to the holobiont. With coral reefs currently under extreme threat from climate change, there is a pressing need to improve our understanding on the stress tolerance and stress avoidance mechanisms of Symbiodinium spp. Reactive oxygen species (ROS) such as singlet oxygen are central players in mediating various stress responses; however, the detection of ROS using specific dyes is still far from definitive in intact Symbiodinium cells due to the hindrance of uptake of certain fluorescent dyes because of the presence of the cell wall. Protoplast technology provides a promising platform for studying oxidative stress with the main advantage of removed cell wall, however the preparation of viable protoplasts remains a significant challenge. Previous studies have successfully applied cellulose-based protoplast preparation in Symbiodiniaceae; however, the protoplast formation and regeneration process was found to be suboptimal. Here, we present a microfluidics-based platform which allowed protoplast isolation from individually trapped Symbiodinium cells, by using a precisely adjusted flow of cell wall digestion enzymes (cellulase and macerozyme). Trapped single cells exhibited characteristic changes in their morphology, cessation of cell division and a slight decrease in photosynthetic activity during protoplast formation. Following digestion and transfer to regeneration medium, protoplasts remained photosynthetically active, regrew cell walls, regained motility, and entered exponential growth. Elevated flow rates in the microfluidic chambers resulted in somewhat faster protoplast formation; however, cell wall digestion at higher flow rates partially compromised photosynthetic activity. Physiologically competent protoplasts prepared from trapped cells in microfluidic chambers allowed for the first time the visualization of the intracellular localization of singlet oxygen (using Singlet Oxygen Sensor Green dye) in Symbiodiniaceae, potentially opening new avenues for studying oxidative stress. LA - English DB - MTMT ER - TY - JOUR AU - Patil, Priyanka Pradeep AU - Vass, Imre AU - Szabó, Milán TI - Characterization of the Wave Phenomenon in Flash-Induced Fluorescence Relaxation and Its Application to Study Cyclic Electron Pathways in Microalgae JF - INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES J2 - INT J MOL SCI VL - 23 PY - 2022 IS - 9 SN - 1661-6596 DO - 10.3390/ijms23094927 UR - https://m2.mtmt.hu/api/publication/32799849 ID - 32799849 N1 - Funding Agency and Grant Number: National Research, Development and Innovation Office [FK128977]; Hungarian Academy of Sciences, MTA Premium Postdoctoral Research Program [PREMIUM-2017-38] Funding text: This research was funded by the National Research, Development and Innovation Office, grant number FK128977 and the Hungarian Academy of Sciences, MTA Premium Postdoctoral Research Program, grant number PREMIUM-2017-38. The APC was funded by National Research, Development and Innovation Office, grant number FK128977. LA - English DB - MTMT ER - TY - JOUR AU - Patil, Priyanka Pradeep AU - Mohammad Aslam, Sabit AU - Vass, Imre AU - Szabó, Milán TI - Characterization of the wave phenomenon of flash-induced chlorophyll fluorescence in Chlamydomonas reinhardtii JF - PHOTOSYNTHESIS RESEARCH J2 - PHOTOSYNTH RES VL - 152 PY - 2022 SP - 235 EP - 244 PG - 10 SN - 0166-8595 DO - 10.1007/s11120-022-00900-3 UR - https://m2.mtmt.hu/api/publication/32677799 ID - 32677799 N1 - Funding Agency and Grant Number: ELKH Biological Research Center; National Research, Development and Innovation OfficeNational Research, Development & Innovation Office (NRDIO) - Hungary [NKFIH FK128977]; Hungarian Academy of Sciences, MTA Premium Postdoctoral Research Program [PREMIUM-2017-38] Funding text: Open access funding provided by ELKH Biological Research Center. The work was supported by the National Research, Development and Innovation Office (NKFIH FK128977) and the Hungarian Academy of Sciences, MTA Premium Postdoctoral Research Program (Grant ID: PREMIUM-2017-38). LA - English DB - MTMT ER - TY - JOUR AU - Iwasaki, Kenji AU - Szabó, Milán AU - Tamburic, Bojan AU - Evenhuis, Christian AU - Zavafer, Alonso AU - Kuzhiumparambil, Unnikrishnan AU - Ralph, Peter TI - Investigating the impact of light quality on macromolecular of Chaetoceros muelleri JF - FUNCTIONAL PLANT BIOLOGY J2 - FUNCT PLANT BIOL VL - 49 PY - 2022 IS - 5-6 Special Issue SP - 554 EP - 564 PG - 11 SN - 1445-4408 DO - 10.1071/FP21131 UR - https://m2.mtmt.hu/api/publication/32473846 ID - 32473846 N1 - Funding Agency and Grant Number: Climate Change Cluster (C3) of the University of Technology Sydney (Australia) Funding text: This work was supported by funding from the Climate Change Cluster (C3) of the University of Technology Sydney (Australia). AB - Diatoms (Bacillariophyceae) are important to primary productivity of aquatic ecosystems. This algal group is also a valuable source of high value compounds that are utilised as aquaculture feed. The productivity of diatoms is strongly driven by light and CO2 availability, and macro- and micronutrient concentrations. The light dependency of biomass productivity and metabolite composition is well researched in diatoms, but information on the impact of light quality, particularly the productivity return on energy invested when using different monochromatic light sources, remains scarce. In this work, the productivity return on energy invested of improving growth rate, photosynthetic activity, and metabolite productivity of the diatom Chaetoceros muelleri under defined wavelengths (blue, red, and green) as well as while light is analysed. By adjusting the different light qualities to equal photosynthetically utilisable radiation, it was found that the growth rate and photosynthetic oxygen evolution was unchanged under white, blue, and green light, but it was lower under red light. Blue light improved the productivity return on energy invested for biomass, total protein, total lipid, total carbohydrate, and in fatty acids production, which would suggest that blue light should be used for aquaculture feed production. LA - English DB - MTMT ER - TY - JOUR AU - Szabó, Milán AU - Zavafer, Alonso TI - Photoinhibition, photo-ecophysiology, and biophysics, a special issue in honor of Wah Soon Chow PREFACE JF - PHOTOSYNTHESIS RESEARCH J2 - PHOTOSYNTH RES VL - 149 PY - 2021 IS - 1-2 SP - 1 EP - 3 PG - 3 SN - 0166-8595 DO - 10.1007/s11120-021-00865-9 UR - https://m2.mtmt.hu/api/publication/32155102 ID - 32155102 N1 - Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network (ELKH), Szeged, Hungary Climate Change Cluster, University of Technology Sydney, Ultimo, 2007, Australia Research School of Biology, Australian National University, Canberra, 2600, Australia Export Date: 14 January 2022 CODEN: PHRSD Correspondence Address: Szabó, M.; Institute of Plant Biology, Hungary; email: szabo.milan@brc.hu Correspondence Address: Zavafer, A.; Research School of Biology, Australia; email: alonso.zavaleta@anu.edu.au LA - English DB - MTMT ER -