{"title":"Effects of different light conditions on morphological, anatomical, photosynthetic and biochemical parameters of Cypripedium macranthos Sw.","authors":"Yuqing Zhang, Wei Liu, Xi Lu, Shuang Li, Ying Li, Yuze Shan, Shizhuo Wang, Yunwei Zhou, Lifei Chen","doi":"10.1007/s11120-024-01100-x","DOIUrl":"10.1007/s11120-024-01100-x","url":null,"abstract":"<p><p>In this study, the morphological (plant height, leaf length and width, stem diameter and leaf number), anatomical (epidermal cell density and thickness, Stomatal length and width), photosynthetic (net photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO<sub>2</sub> concentration, relative humidity, leaf temperature and chlorophyll fluorescence parameters) and biochemical parameters (the content of soluble sugar, soluble protein, proline, malondialdehyde and electrical conductivity) of Cypripedium macranthos Sw. in Changbai Mountain were determined under different light conditions (L10, L30, L50, L100). The results showed that morphological values including plant height, leaf area, stem diameter and leaf number of C. macranthos were smaller under the condition of full light at L100. The epidermal cell density and epidermal thickness of C. macranthos were the highest under L30 and L50 treatments, respectively. It had the highest net photosynthetic rate (Pn) and chlorophyll content under L50 treatment. Meanwhile, correlation analysis indicated that photosynthetically active radiation (PAR) and water use efficiency (WUE) were the main factors influencing Pn. C. macranthos accumulated more soluble sugars and soluble proteins under L100 treatment, while the degree of membrane peroxidation was the highest and the plant was severely damaged. In summary, the adaptability of C. macranthos to light conditions is ranked as follows L50 > L30 > L10 > L100. Appropriate light conditions for C. macranthos are 30%-50% of full light, which should be taken into account in protection and cultivation.</p>","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140857502","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}
Photosynthesis ResearchPub Date : 2024-06-01Epub Date: 2024-03-15DOI: 10.1007/s11120-024-01091-9
Faiza Arshad, Julian J Eaton-Rye
{"title":"Indirect interactions involving the PsbM or PsbT subunits and the PsbO, PsbU and PsbV proteins stabilize assembly and activity of Photosystem II in Synechocystis sp. PCC 6803.","authors":"Faiza Arshad, Julian J Eaton-Rye","doi":"10.1007/s11120-024-01091-9","DOIUrl":"10.1007/s11120-024-01091-9","url":null,"abstract":"<p><p>The low-molecular-weight PsbM and PsbT proteins of Photosystem II (PS II) are both located at the monomer-monomer interface of the mature PS II dimer. Since the extrinsic proteins are associated with the final step of assembly of an active PS II monomer and, in the case of PsbO, are known to impact the stability of the PS II dimer, we have investigated the potential cooperativity between the PsbM and PsbT subunits and the PsbO, PsbU and PsbV extrinsic proteins. Blue-native polyacrylamide electrophoresis and western blotting detected stable PS II monomers in the ∆PsbM:∆PsbO and ∆PsbT:∆PsbO mutants that retained sufficient oxygen-evolving activity to support reduced photoautotrophic growth. In contrast, the ∆PsbM:∆PsbU and ∆PsbT:∆PsbU mutants assembled dimeric PS II at levels comparable to wild type and supported photoautotrophic growth at rates similar to those obtained with the corresponding ∆PsbM and ∆PsbT cells. Removal of PsbV was more detrimental than removal of PsbO. Only limited levels of dimeric PS II were observed in the ∆PsbM:∆PsbV mutant and the overall reduced level of assembled PS II in this mutant resulted in diminished rates of photoautotrophic growth and PS II activity below those obtained in the ∆PsbM:∆PsbO and ∆PsbT:∆PsbO strains. In addition, the ∆PsbT:∆PsbV mutant did not assemble active PS II centers although inactive monomers could be detected. The inability of the ∆PsbT:∆PsbV mutant to grow photoautotrophically, or to evolve oxygen, suggested a stable oxygen-evolving complex could not assemble in this mutant.</p>","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11108944/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140137114","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}
Photosynthesis ResearchPub Date : 2024-06-01Epub Date: 2024-05-03DOI: 10.1007/s11120-024-01092-8
Syed Bilal Hussain, Joseph Stinziano, Myrtho O Pierre, Christopher Vincent
{"title":"Accurate photosynthetic parameter estimation at low stomatal conductance: effects of cuticular conductance and instrumental noise.","authors":"Syed Bilal Hussain, Joseph Stinziano, Myrtho O Pierre, Christopher Vincent","doi":"10.1007/s11120-024-01092-8","DOIUrl":"10.1007/s11120-024-01092-8","url":null,"abstract":"<p><p>Accurate estimation of photosynthetic parameters is essential for understanding plant physiological limitations and responses to environmental factors from the leaf to the global scale. Gas exchange is a useful tool to measure responses of net CO<sub>2</sub> assimilation (A) to internal CO<sub>2</sub> concentration (C<sub>i</sub>), a necessary step in estimating photosynthetic parameters including the maximum rate of carboxylation (V<sub>cmax</sub>) and the electron transport rate (J<sub>max</sub>). However, species and environmental conditions of low stomatal conductance (g<sub>sw</sub>) reduce the signal-to-noise ratio of gas exchange, challenging estimations of C<sub>i</sub>. Previous works showed that not considering cuticular conductance to water (g<sub>cw</sub>) can lead to significant errors in estimating C<sub>i</sub>, because it has a different effect on total conductance to CO<sub>2</sub> (g<sub>tc</sub>) than does g<sub>sw</sub>. Here we present a systematic assessment of the need for incorporating g<sub>cw</sub> into C<sub>i</sub> estimates. In this study we modeled the effect of g<sub>cw</sub> and of instrumental noise and quantified these effects on photosynthetic parameters in the cases of four species with varying g<sub>sw</sub> and g<sub>cw</sub>, measured using steady-state and constant ramping techniques, like the rapid A/C<sub>i</sub> response method. We show that not accounting for g<sub>cw</sub> quantitatively influences C<sub>i</sub> and the resulting V<sub>cmax</sub> and J<sub>max</sub>, particularly when g<sub>cw</sub> exceeds 7% of the total conductance to water. The influence of g<sub>cw</sub> was not limited to low g<sub>sw</sub> species, highlighting the importance of species-specific knowledge before assessing A/C<sub>i</sub> curves. Furthermore, at low g<sub>sw</sub> instrumental noise can affect C<sub>i</sub> estimation, but the effect of instrumental noise can be minimized using constant-ramping rather than steady-state techniques. By incorporating these considerations, more precise measurements and interpretations of photosynthetic parameters can be obtained in a broader range of species and environmental conditions.</p>","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11108943/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140850962","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}
Alice Haddy, Shilpa Beravolu, Jeremiah Johnston, Hannah Kern, Monica McDaniel, Brandon Ore, Rachel Reed, Henry Tai
{"title":"Exploring the interdependence of calcium and chloride activation of O<sub>2</sub> evolution in photosystem II.","authors":"Alice Haddy, Shilpa Beravolu, Jeremiah Johnston, Hannah Kern, Monica McDaniel, Brandon Ore, Rachel Reed, Henry Tai","doi":"10.1007/s11120-024-01094-6","DOIUrl":"https://doi.org/10.1007/s11120-024-01094-6","url":null,"abstract":"<p><p>Calcium and chloride are activators of oxygen evolution in photosystem II (PSII), the light-absorbing water oxidase of higher plants, algae, and cyanobacteria. Calcium is an essential part of the catalytic Mn<sub>4</sub>CaO<sub>5</sub> cluster that carries out water oxidation and chloride has two nearby binding sites, one of which is associated with a major water channel. The co-activation of oxygen evolution by the two ions is examined in higher plant PSII lacking the extrinsic PsbP and PsbQ subunits using a bisubstrate enzyme kinetics approach. Analysis of three different preparations at pH 6.3 indicates that the Michaelis constant, K<sub>M</sub>, for each ion is less than the dissociation constant, K<sub>S</sub>, and that the affinity of PSII for Ca<sup>2+</sup> is about ten-fold greater than for Cl<sup>-</sup>, in agreement with previous studies. Results are consistent with a sequential binding model in which either ion can bind first and each promotes the activation by the second ion. At pH 5.5, similar results are found, except with a higher affinity for Cl<sup>-</sup> and lower affinity for Ca<sup>2+</sup>. Observation of the slow-decaying Tyr Z radical, Y<sub>Z</sub>•, at 77 K and the coupled S<sub>2</sub>Y<sub>Z</sub>• radical at 10 K, which are both associated with Ca<sup>2+</sup> depletion, shows that Cl<sup>-</sup> is necessary for their observation. Given the order of electron and proton transfer events, this indicates that chloride is required to reach the S<sub>3</sub> state preceding Ca<sup>2+</sup> loss and possibly for stabilization of Y<sub>Z</sub>• after it forms. Interdependence through hydrogen bonding is considered in the context of the water environment that intervenes between Cl<sup>-</sup> at the Cl-1 site and the Ca<sup>2+</sup>/Tyr Z region.</p>","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140850963","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}
Govindjee Govindjee, Bas Amesz, Győző Garab, Alexandrina Stirbet
{"title":"Remembering Jan Amesz (1934–2001): a great gentleman, a major discoverer, and an internationally renowned biophysicist of both oxygenic and anoxygenic photosynthesisa","authors":"Govindjee Govindjee, Bas Amesz, Győző Garab, Alexandrina Stirbet","doi":"10.1007/s11120-024-01102-9","DOIUrl":"https://doi.org/10.1007/s11120-024-01102-9","url":null,"abstract":"<p>We present here the research contributions of Jan Amesz (1934–2001) on deciphering the details of the early physico-chemical steps in oxygenic photosynthesis in plants, algae and cyanobacteria, as well as in anoxygenic photosynthesis in purple, green, and heliobacteria. His research included light absorption and the mechanism of excitation energy transfer, primary photochemistry, and electron transfer steps until the reduction of pyridine nucleotides. Among his many discoveries, we emphasize his 1961 proof, with L. N. M. Duysens, of the “series scheme” of oxygenic photosynthesis, through antagonistic effects of Light I and II on the redox state of cytochrome <i>f</i>. Further, we highlight the following research on oxygenic photosynthesis: the experimental direct proof that plastoquinone and plastocyanin function at their respective places in the Z-scheme. In addition, Amesz’s major contributions were in unraveling the mechanism of excitation energy transfer and electron transport steps in anoxygenic photosynthetic bacteria (purple, green and heliobacteria). Before we present his research, focusing on his key discoveries, we provide a glimpse of his personal life. We end this Tribute with reminiscences from three of his former doctoral students (Sigi Neerken; Hjalmar Pernentier, and Frank Kleinherenbrink) and from several scientists (Suleyman Allakhverdiev; Robert Blankenship; Richard Cogdell) including two of the authors (G. Garab and A. Stirbet) of this Tribute.</p>","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140842084","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":"The S1 to S2 and S2 to S3 state transitions in plant photosystem II: relevance to the functional and structural heterogeneity of the water oxidizing complex.","authors":"Andrea Pavlou, S. Styring, Fikret Mamedov","doi":"10.1007/s11120-024-01096-4","DOIUrl":"https://doi.org/10.1007/s11120-024-01096-4","url":null,"abstract":"","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140656282","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}
Kinga Böde, Uroš Javornik, O. Dlouhý, O. Zsíros, Avratanu Biswas, I. Domonkos, P. Šket, V. Karlický, B. Ughy, P. Lambrev, V. Špunda, J. Plavec, G. Garab
{"title":"Role of isotropic lipid phase in the fusion of photosystem II membranes.","authors":"Kinga Böde, Uroš Javornik, O. Dlouhý, O. Zsíros, Avratanu Biswas, I. Domonkos, P. Šket, V. Karlický, B. Ughy, P. Lambrev, V. Špunda, J. Plavec, G. Garab","doi":"10.1007/s11120-024-01097-3","DOIUrl":"https://doi.org/10.1007/s11120-024-01097-3","url":null,"abstract":"","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140656502","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":"Intramolecular charge transfer and the function of vibronic excitons in photosynthetic light harvesting.","authors":"Warren F Beck","doi":"10.1007/s11120-024-01095-5","DOIUrl":"https://doi.org/10.1007/s11120-024-01095-5","url":null,"abstract":"","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140660453","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":"The synergy between the PscC subunits for electron transfer to the P840 special pair in Chlorobaculum tepidum","authors":"Alexandros Lyratzakis, Vangelis Daskalakis, Hao Xie, Georgios Tsiotis","doi":"10.1007/s11120-024-01093-7","DOIUrl":"https://doi.org/10.1007/s11120-024-01093-7","url":null,"abstract":"<p>The primary photochemical reaction of photosynthesis in green sulfur bacteria occurs in the homodimer PscA core proteins by a special chlorophyll pair. The light induced excited state of the special pair producing P<sub>840</sub><sup>+</sup> is rapidly reduced by electron transfer from one of the two PscC subunits. Molecular dynamics (MD) simulations are combined with bioinformatic tools herein to provide structural and dynamic insight into the complex between the two PscA core proteins and the two PscC subunits. The microscopic dynamic model involves extensive sampling at atomic resolution and at a cumulative time-scale of 22µs and reveals well defined protein–protein interactions. The membrane complex is composed of the two PscA and the two PscC subunits and macroscopic connections are revealed within a putative electron transfer pathway from the PscC subunit to the special pair P<sub>840</sub> located within the PscA subunits. Our results provide a structural basis for understanding the electron transport to the homodimer RC of the green sulfur bacteria. The MD based approach can provide the basis to further probe the PscA-PscC complex dynamics and observe electron transfer therein at the quantum level. Furthermore, the transmembrane helices of the different PscC subunits exert distinct dynamics in the complex.</p>","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140584122","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":"Stimulated X-ray emission spectroscopy","authors":"Uwe Bergmann","doi":"10.1007/s11120-024-01080-y","DOIUrl":"https://doi.org/10.1007/s11120-024-01080-y","url":null,"abstract":"<p>We describe an emerging hard X-ray spectroscopy technique, stimulated X-ray emission spectroscopy (S-XES). S-XES has the potential to characterize the electronic structure of 3d transition metal complexes with spectral information currently not reachable and might lead to the development of new ultrafast X-ray sources with properties beyond the state of the art. S-XES has become possible with the emergence of X-ray free-electron lasers (XFELs) that provide intense femtosecond X-ray pulses that can be employed to generate a population inversion of core–hole excited states resulting in stimulated X-ray emission. We describe the instrumentation, the various types of S-XES, the potential applications, the experimental challenges, and the feasibility of applying S-XES to characterize dilute systems, including the Mn<sub>4</sub>Ca cluster in the oxygen evolving complex of photosystem II.</p>","PeriodicalId":20130,"journal":{"name":"Photosynthesis Research","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140584257","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}