@article{MTMT:34043896, title = {Characterization of the Flash-Induced Fluorescence Wave Phenomenon in the Coral Endosymbiont Algae, Symbiodiniaceae}, url = {https://m2.mtmt.hu/api/publication/34043896}, author = {Mohammad Aslam, Sabit and Vass, Imre and Szabó, Milán}, doi = {10.3390/ijms24108712}, journal-iso = {INT J MOL SCI}, journal = {INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES}, volume = {24}, unique-id = {34043896}, issn = {1661-6596}, abstract = {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.}, keywords = {INHIBITION; PHOTOSYSTEM-II; PHOTOSYNTHESIS; CHLOROPHYLL FLUORESCENCE; CHLOROPHYLL FLUORESCENCE; Biochemistry & Molecular Biology; symbiotic microalgae; linear electron flow}, year = {2023}, eissn = {1422-0067} } @article{MTMT:33025641, title = {Heat-Induced Photosynthetic Responses of Symbiodiniaceae Revealed by Flash-Induced Fluorescence Relaxation Kinetics}, url = {https://m2.mtmt.hu/api/publication/33025641}, author = {Mohammad Aslam, Sabit and Patil, Priyanka Pradeep and Vass, Imre and Szabó, Milán}, doi = {10.3389/fmars.2022.932355}, journal-iso = {FRONT MAR SCI}, journal = {FRONTIERS IN MARINE SCIENCE}, volume = {9}, unique-id = {33025641}, year = {2022}, eissn = {2296-7745} } @article{MTMT:32677799, title = {Characterization of the wave phenomenon of flash-induced chlorophyll fluorescence in Chlamydomonas reinhardtii}, url = {https://m2.mtmt.hu/api/publication/32677799}, author = {Patil, Priyanka Pradeep and Mohammad Aslam, Sabit and Vass, Imre and Szabó, Milán}, doi = {10.1007/s11120-022-00900-3}, journal-iso = {PHOTOSYNTH RES}, journal = {PHOTOSYNTHESIS RESEARCH}, volume = {152}, unique-id = {32677799}, issn = {0166-8595}, year = {2022}, eissn = {1573-5079}, pages = {235-244} } @article{MTMT:31469338, title = {Role of cyclic electron transport mutations pgrl1 and pgr5 in acclimation process to high light in Chlamydomonas reinhardtii}, url = {https://m2.mtmt.hu/api/publication/31469338}, author = {Yadav, Ranay Mohan and Mohammad Aslam, Sabit and Madireddi, Sai Kiran and Chouhan, Nisha and Subramanyam, Rajagopal}, doi = {10.1007/s11120-020-00751-w}, journal-iso = {PHOTOSYNTH RES}, journal = {PHOTOSYNTHESIS RESEARCH}, volume = {146}, unique-id = {31469338}, issn = {0166-8595}, abstract = {Light is crucial for photosynthesis, but the amount of light that exceeds an organism's assimilation efficacy can lead to photo-oxidative damage and even cell death. In Chlamydomonas (C). reinhardtii cyclic electron flow (CEF) is very important for the elicitation of non-photochemical quenching (NPQ) by controlling the acidification of thylakoid lumen. This process requires the cooperation of proton gradient regulation (PGR) proteins, PGRL1 and PGR5. Here, we compared the growth pattern and photosynthetic activity between wild type (137c, t222+) and mutants impaired in CEF (pgrl1 and pgr5) under photoautotrophic and photoheterotrophic conditions. We have observed the discriminative expression of NPQ in the mutants impaired in CEF of pgrl1 and pgr5. The results obtained from the mutants showed reduced cell growth and density, Chl a/b ratio, fluorescence, electron transport rate, and yield of photosystem (PS)II. These mutants have reduced capability to develop a strong NPQ indicating that the role of CEF is very crucial for photoprotection. Moreover, the CEF mutant exhibits increased photosensitivity compared with the wild type. Therefore, we suggest that besides NPQ, the fraction of non-regulated non-photochemical energy loss (NO) also plays a crucial role during high light acclimation despite a low growth rate. This low NPQ rate may be due to less influx of protons coming from the CEF in cases of pgrl1 and pgr5 mutants. These results are discussed in terms of the relative photoprotective benefit, related to the thermal dissipation of excess light in photoautotrophic and photoheterotrophic conditions.}, keywords = {CHLOROPHYLL FLUORESCENCE; non-photochemical quenching; Chlamydomonas reinhardtii; High light; photosystems; Cyclic electron transport}, year = {2020}, eissn = {1573-5079}, pages = {247-258}, orcid-numbers = {Subramanyam, Rajagopal/0000-0003-3872-8390} }