Photosynthesis Research最新文献

{"title":"Physical properties of chlorophyll-quinone conjugates prepared via Friedel-Crafts reaction.","authors":"Saki Kichishima, Kana Sakaguchi, Hitoshi Tamiaki","doi":"10.1007/s11120-024-01132-3","DOIUrl":"10.1007/s11120-024-01132-3","url":null,"abstract":"<p><p>Pheophytin-a derivatives possessing plastoquinone and phylloquinone analogs in the peripheral 3-substituent were prepared by Friedel-Crafts reactions of a 3-hydroxymethyl-chlorin as one of the chlorophyll-a derivatives with benzo- and naphthohydroquinones, respectively, and successive oxidation of the 1,4-dihydroxy-aryl groups in the resulting dehydration products. The 3-quinonylmethyl-chlorins exhibited ultraviolet-visible absorption and circular dichroism spectra in acetonitrile, which were composed of those of the starting 3-hydroxymethyl-chlorin and the corresponding methylated benzo- and naphthoquinones. No intramolecular interaction between the chlorin and quinone π-systems was observed in the solution owing to the methylene spacer. The first reduction potentials of the quinone moieties in the synthetic conjugates were determined by cyclic voltammetry and shifted positively from those of the reference quinones. The former quinonyl groups were reduced more readily by approximately 0.1 V than the latter quinones, which was ascribable to the stabilization of the quinonyl anion radical by the nearby macrocyclic chlorin π-chromophore. This observation implied that the reduction potentials of quinones were regulated by the close pheophytin-a derivative by through-space interaction. Considering the charge shift from pheophytin-a anion radical to plastoquinone and phylloquinone in reaction centers of photosystems II and I, respectively, the reduction potentials of these quinones as a determinant factor of the rapid electron transfer process would be dependent on the pheophytin-a in the photosynthetic reaction centers of oxygenic phototrophs as well as on the neighboring peptides.</p>","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":"163 1","pages":"8"},"PeriodicalIF":2.9,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11742327/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143056098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effectiveness of salt priming and plant growth-promoting bacteria in mitigating salt-induced photosynthetic damage in melon.","authors":"Hüsna Dolu, Dilek Killi, Serpil Bas, Deniz Sezlev Bilecen, Musa Seymen","doi":"10.1007/s11120-024-01128-z","DOIUrl":"10.1007/s11120-024-01128-z","url":null,"abstract":"<p><p>Seed priming and plant growth-promoting bacteria (PGPB) may alleviate salt stress effects. We exposed a salt-sensitive variety of melon to salinity following seed priming with NaCl and inoculation with Bacillus. Given the sensitivity of photosystem II (PSII) to salt stress, we utilized dark- and light-adapted chlorophyll fluorescence alongside analysis of leaf stomatal conductance of water vapour (G_sw). Priming increased total seed germination by 15.5% under salt-stress. NaCl priming with Bacillus inoculation (PB) increased total leaf area (LA) by 45% under control and 15% under stress. Under the control condition, priming (P) reduced membrane permeability (RMP) by 36% and PB by 55%, while under stress Bacillus (BS) reduced RMP by 10%. Although Bacillus inoculation (B) and priming (P) treatments did not show significant effects on some PSII efficiency parameters (F_V/F_M, ABS/RC, PI_ABS, F_M), the BS treatment induced a significantly higher quantum efficiency of PSII (ΦPSII) and increased G_sw by 159% in the final week of the experiment. The BS treatment reduced electron transport rate per reaction center (ET_O/RC) by 10% in comparison to the salt treatment, which showed less reaction centre damage. Bacillus inoculation and seed priming treatment under the stressed condition (PBS) induced an increase in electron transport rate of 40%. Salt stress started to show significant effects on PSII after 12 days, and adversely impacted all morphological and photosynthetic parameters after 22 days. Salt priming and PGPB mitigated the negative impacts of salt stress and may serve as effective tools in future-proofing saline agriculture.</p>","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":"163 1","pages":"7"},"PeriodicalIF":2.9,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143009760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetics of reformation of the S₀ state capable of progressing to the S₁ state after the O₂ release by photosystem II.","authors":"Alain Boussac, Julien Sellés, Miwa Sugiura","doi":"10.1007/s11120-024-01131-4","DOIUrl":"10.1007/s11120-024-01131-4","url":null,"abstract":"<p><p>The active site for water oxidation in photosystem II (PSII) comprises a Mn₄CaO₅ cluster adjacent to a redox-active tyrosine residue (Tyr_Z). During the water-splitting process, the enzyme transitions through five sequential oxidation states (S₀ to S₄), with O₂ evolution occurring during the S₃Tyr_Z· to S₀Tyr_Z transition. Chloride also plays a role in this mechanism. Using PSII from Thermosynechococcus vestitus, where Ca and Cl were replaced with Sr and Br to slow the S₃Tyr_Z· to S₀Tyr_Z + O₂ transition (t_1/2 ~ 5 ms at room temperature), it was observed that the recovery of a S₀ state, defined as the state able to progress to S₁, exhibits similar kinetics (t_1/2 ~ 5 ms). This suggests that in CaCl-PSII, the reformation of the functional S₀ state directly follows the S₃Tyr_Z· to S₀Tyr_Z + O₂ transition, with no additional delay required for the insertion of a new substrate water molecule (O5) and associated protons.</p>","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":"163 1","pages":"5"},"PeriodicalIF":2.9,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142984568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Testing the kinetic tradeoff between bicarbonate versus phosphoenolpyruvate affinity and glucose-6 phosphate response of phosphoenolpyruvate carboxylase from two C₄ grasses.","authors":"Ryan L Wessendorf, Matt Stata, Asaph B Cousins","doi":"10.1007/s11120-024-01123-4","DOIUrl":"10.1007/s11120-024-01123-4","url":null,"abstract":"<p><p>Phosphoenolpyruvate (PEP) carboxylase (PEPC) has an anaplerotic role in central plant metabolism but also initiates the carbon concentrating mechanism during C₄ photosynthesis. The C₄ PEPC has different binding affinities (K_m) for PEP (K_0.5PEP) and HCO₃^- (K_0.5HCO3), and allosteric regulation by glucose-6-phosphate (G6-P) compared to non-photosynthetic isoforms. These differences are linked to specific changes in amino acids within PEPC. For example, region II (residues 302-433, Zea mays numbering) has been identified as important for G6-P regulation and within this region residue 353 may be conserved in C₄ PEPC enzymes. Additionally, residue 780 influences the C₄ PEPC kinetic properties and may interact with region II as well as residue 353 to influence G6-P regulation. We test the hypothesis that variation within region II, including residue 353, and their interactions with residue 780 influence the kinetic and allosteric regulation by G6-P of two C₄ PEPC isozymes from two C₄ grasses. The data does not support a kinetic tradeoff between K_0.5HCO3 and K_0.5PEP in these PEPC isozymes. Additionally, these enzymes had different response to G6-P that was only partially attributed to region II, residue 353 and residue 780. This data provides new insights into factors influencing the kinetic variation of C₄ PEPC isozymes.</p>","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":"163 1","pages":"6"},"PeriodicalIF":2.9,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142984571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Eustress responses of Musa acuminata cv. red banana using LED spectra.","authors":"Jonathan Bege, Wei Quan Pang, Bee Lynn Chew, Elayabalan Sivalingam, Sankar Manickam, Mohamad Fadhli Mad' Atari, Sreeramanan Subramaniam","doi":"10.1007/s11120-024-01130-5","DOIUrl":"10.1007/s11120-024-01130-5","url":null,"abstract":"<p><p>This study examined the impacts of different LED spectra on the growth of in vitro cultures of Musa acuminata cv. red banana and their biochemical profile, including the antioxidant enzymes catalase and ascorbate peroxidase, photosynthetic pigment and accumulation of total carbohydrate content. The far-red LEDs significantly increase shoot elongation (10.04 cm). The greatest number of shoots (2.97) and the greatest multiplication rate (80%) were obtained under the treatment with blue + red LEDs. The formation of microshoots were also enhanced by blue and white LED exposure in a range of 2-2.57 shoots per explant. Root formation was also stimulated by dichromatic blue + red (6.00) LED using MS medium with 2 µM indole-3-butyric acid (IBA). The enzymes catalase and ascorbate peroxidase were significantly up-regulated by irradiation with far-red (0.11 ± 0.02 CAT, 0.18 ± 0.04 APX U/mg) and blue (0.08 ± 0.01CAT, 0.10 ± 0.01APX U/mg) LED light. Total chlorophyll (0.45 to 0.80 mg/g) was elevated significantly by blue, blue + red and mint-white LED. On the other hand, carotenoids (12.08-14.61 mg/g) were significantly boosted by blue + red, red and mint-white LED light. Meanwhile, porphyrin (294.10-350.57 mg/g) was highly synthesised after irradiation with mint-white light. Irradiation with LED light significantly increased the accumulation of carbohydrates with the highest carbohydrate content under blue + red LED light (102.22 ± 2.46 mg/g) and blue light (91.69 ± 2.10 mg/g). In conclusion, these results confirm that the vegetative properties and biochemical profile of red banana in vitro are eustress response to LED spectra.</p>","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":"163 1","pages":"4"},"PeriodicalIF":2.9,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142979464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights from Ca²⁺→Sr²⁺ substitution on the mechanism of O-O bond formation in photosystem II.","authors":"Gabriel Bury, Yulia Pushkar","doi":"10.1007/s11120-024-01117-2","DOIUrl":"10.1007/s11120-024-01117-2","url":null,"abstract":"<p><p>In recent years, there has been a steady interest in unraveling the intricate mechanistic details of water oxidation mechanism in photosynthesis. Despite the substantial progress made over several decades, a comprehensive understanding of the precise kinetics underlying O-O bond formation and subsequent evolution remains elusive. However, it is well-established that the oxygen evolving complex (OEC), specifically the CaMn₄O₅ cluster, plays a crucial role in O-O bond formation, undergoing a series of four oxidative events as it progresses through the S-states of the Kok cycle. To gain further insights into the OEC, researchers have explored the substitution of the Ca²⁺ cofactor with strontium (Sr), the sole atomic replacement capable of retaining oxygen-evolving activity. Empirical investigations utilizing spectroscopic techniques such as XAS, XRD, EPR, FTIR, and XANES have been conducted to probe the structural consequences of Ca²⁺→Sr²⁺ substitution. In parallel, the development of DFT and QM/MM computational models has explored different oxidation and protonation states, as well as variations in ligand coordination at the catalytic center involving amino acid residues. In this review, we critically evaluate and integrate these computational and spectroscopic approaches, focusing on the structural and mechanistic implications of Ca²⁺→Sr²⁺ substitution in PS II. We contribute DFT modelling and simulate EXAFS Fourier transforms of Sr-substituted OEC, analyzing promising structures of the S₃ state. Through the combination of computational modeling and spectroscopic investigations, valuable insights have been gained, developing a deeper understanding of the photosynthetic process.</p>","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":" ","pages":"331-351"},"PeriodicalIF":2.9,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142056371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phylogenetic and spectroscopic insights on the evolution of core antenna proteins in cyanobacteria.","authors":"Sandeep Biswas, Dariusz M Niedzwiedzki, Michelle Liberton, Himadri B Pakrasi","doi":"10.1007/s11120-023-01046-6","DOIUrl":"10.1007/s11120-023-01046-6","url":null,"abstract":"<p><p>Light harvesting by antenna systems is the initial step in a series of electron-transfer reactions in all photosynthetic organisms, leading to energy trapping by reaction center proteins. Cyanobacteria are an ecologically diverse group and are the simplest organisms capable of oxygenic photosynthesis. The primary light-harvesting antenna in cyanobacteria is the large membrane extrinsic pigment-protein complex called the phycobilisome. In addition, cyanobacteria have also evolved specialized membrane-intrinsic chlorophyll-binding antenna proteins that transfer excitation energy to the reaction centers of photosystems I and II (PSI and PSII) and dissipate excess energy through nonphotochemical quenching. Primary among these are the CP43 and CP47 proteins of PSII, but in addition, some cyanobacteria also use IsiA and the prochlorophyte chlorophyll a/b binding (Pcb) family of proteins. Together, these proteins comprise the CP43 family of proteins owing to their sequence similarity with CP43. In this article, we have revisited the evolution of these chlorophyll-binding antenna proteins by examining their protein sequences in parallel with their spectral properties. Our phylogenetic and spectroscopic analyses support the idea of a common ancestor for CP43, IsiA, and Pcb proteins, and suggest that PcbC might be a distant ancestor of IsiA. The similar spectral properties of CP47 and IsiA suggest a closer evolutionary relationship between these proteins compared to CP43.</p>","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":" ","pages":"197-210"},"PeriodicalIF":2.9,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41130298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Perspectives of cyanobacterial cell factories.","authors":"Anastasios Melis, Diego Alberto Hidalgo Martinez, Nico Betterle","doi":"10.1007/s11120-023-01056-4","DOIUrl":"10.1007/s11120-023-01056-4","url":null,"abstract":"<p><p>Cyanobacteria are prokaryotic photosynthetic microorganisms that can generate, in addition to biomass, useful chemicals and proteins/enzymes, essentially from sunlight, carbon dioxide, and water. Selected aspects of cyanobacterial production (isoprenoids and high-value proteins) and scale-up methods suitable for product generation and downstream processing are addressed in this review. The work focuses on the challenge and promise of specialty chemicals and proteins production, with isoprenoid products and biopharma proteins as study cases, and the challenges encountered in the expression of recombinant proteins/enzymes, which underline the essence of synthetic biology with these microorganisms. Progress and the current state-of-the-art in these targeted topics are emphasized.</p>","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":" ","pages":"459-471"},"PeriodicalIF":2.9,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11615099/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"107592025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exceptional Quantum Efficiency Powers Biomass Production in Halotolerant Algae Picochlorum sp.<sup />","authors":"Colin Gates, Gennady Ananyev, Fatima Foflonker, Debashish Bhattacharya, G Charles Dismukes","doi":"10.1007/s11120-024-01075-9","DOIUrl":"10.1007/s11120-024-01075-9","url":null,"abstract":"<p><p>The green algal genus Picochlorum is of biotechnological interest because of its robust response to multiple environmental stresses. We compared the metabolic performance of P. SE3 and P. oklahomense to diverse microbial phototrophs and observed exceptional performance of photosystem II (PSII) in light energy conversion in both Picochlorum species. The quantum yield (QY) for O₂ evolution is the highest of any phototroph yet observed, 32% (20%) by P. SE3 (P. okl) when normalized to total PSII subunit PsbA (D1) protein, and 80% (75%) normalized per active PSII, respectively. Three factors contribute: (1) an efficient water oxidizing complex (WOC) with the fewest photochemical misses of any organism; (2) faster reoxidation of reduced (PQH₂)_B in P. SE3 than in P. okl. (period-2 Fourier amplitude); and (3) rapid reoxidation of the plastoquinol pool by downstream electron carriers (Cyt b₆f/PETC) that regenerates PQ faster in P. SE3. This performance gain is achieved without significant residue changes around the Q_B site and thus points to a pull mechanism involving faster PQH₂ reoxidation by Cyt b₆f/PETC that offsets charge recombination. This high flux in P. SE3 may be explained by genomically encoded plastoquinol terminal oxidases 1 and 2, whereas P. oklahomense has neither. Our results suggest two distinct types of PSII centers exist, one specializing in linear electron flow and the other in PSII-cyclic electron flow. Several amino acids within D1 differ from those in the low-light-descended D1 sequences conserved in Viridiplantae, and more closely match those in cyanobacterial high-light D1 isoforms, including changes near tyrosine Y_z and a water/proton channel near the WOC. These residue changes may contribute to the exceptional performance of Picochlorum at high-light intensities by increasing the water oxidation efficiency and the electron/proton flux through the PSII acceptors (Q_AQ_B).</p>","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":" ","pages":"439-457"},"PeriodicalIF":2.9,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139703166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Macroscale structural changes of thylakoid architecture during high light acclimation in Chlamydomonas reinhardtii.","authors":"Mimi Broderson, Krishna K Niyogi, Masakazu Iwai","doi":"10.1007/s11120-023-01067-1","DOIUrl":"10.1007/s11120-023-01067-1","url":null,"abstract":"<p><p>Photoprotection mechanisms are ubiquitous among photosynthetic organisms. The photoprotection capacity of the green alga Chlamydomonas reinhardtii is correlated with protein levels of stress-related light-harvesting complex (LHCSR) proteins, which are strongly induced by high light (HL). However, the dynamic response of overall thylakoid structure during acclimation to growth in HL has not been fully understood. Here, we combined live-cell super-resolution microscopy and analytical membrane subfractionation to investigate macroscale structural changes of thylakoid membranes during HL acclimation in Chlamydomonas. Subdiffraction-resolution live-cell imaging revealed that the overall thylakoid structures became thinned and shrunken during HL acclimation. The stromal space around the pyrenoid also became enlarged. Analytical density-dependent membrane fractionation indicated that the structural changes were partly a consequence of membrane unstacking. The analysis of both an LHCSR loss-of-function mutant, npq4 lhcsr1, and a regulatory mutant that over-expresses LHCSR, spa1-1, showed that structural changes occurred independently of LHCSR protein levels, demonstrating that LHCSR was neither necessary nor sufficient to induce the thylakoid structural changes associated with HL acclimation. In contrast, stt7-9, a mutant lacking a kinase of major light-harvesting antenna proteins, had a slower thylakoid structural response to HL relative to all other lines tested but still showed membrane unstacking. These results indicate that neither LHCSR- nor antenna-phosphorylation-dependent HL acclimation are required for the observed macroscale structural changes of thylakoid membranes in HL conditions.</p>","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":" ","pages":"427-437"},"PeriodicalIF":2.9,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11614958/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139098510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}