DOCSLIB.ORG

Chlorophyll Fluorescence: a Probe of Photosynthesis in Vivo

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Chlorophyll Fluorescence: a Probe of Photosynthesis in Vivo ANRV342-PP59-05 ARI 27 March 2008 1:28 Chlorophyll Fluorescence: A Probe of Photosynthesis In Vivo Neil R. Baker Department of Biological Sciences, University of Essex, Colchester, CO4 3SQ, United Kingdom; email: [email protected] Annu. Rev. Plant Biol. 2008. 59:89–113 Key Words The Annual Review of Plant Biology is online at carbon dioxide assimilation, electron transport, imaging, plant.annualreviews.org metabolism, photosystem II photochemistry, stomata This article’s doi: 10.1146/annurev.arplant.59.032607.092759 Abstract Copyright c 2008 by Annual Reviews. The use of chlorophyll fluorescence to monitor photosynthetic per- All rights reserved formance in algae and plants is now widespread. This review exam- 1543-5008/08/0602-0089$20.00 ines how fluorescence parameters can be used to evaluate changes by Miami University of Ohio on 09/23/10. For personal use only. in photosystem II (PSII) photochemistry, linear electron flux, and CO2 assimilation in vivo, and outlines the theoretical bases for the Annu. Rev. Plant Biol. 2008.59:89-113. Downloaded from www.annualreviews.org use of specific fluorescence parameters. Although fluorescence pa- rameters can be measured easily, many potential problems may arise when they are applied to predict changes in photosynthetic perfor- mance. In particular, consideration is given to problems associated with accurate estimation of the PSII operating efficiency measured by fluorescence and its relationship with the rates of linear electron flux and CO2 assimilation. The roles of photochemical and non- photochemical quenching in the determination of changes in PSII operating efficiency are examined. Finally, applications of fluores- cence imaging to studies of photosynthetic heterogeneity and the rapid screening of large numbers of plants for perturbations in pho- tosynthesis and associated metabolism are considered. 89 ANRV342-PP59-05 ARI 27 March 2008 1:28 cence changes in vivo are complex and cor- Contents rect interpretation of changes in fluorescence parameters can often be difficult. Considera- INTRODUCTION................. 90 tion is given to some problems associated with BACKGROUND ................... 90 the measurement of these parameters and the PHOTOSYSTEM II assumptions made when using these param- PHOTOCHEMISTRY .......... 91 eters to evaluate changes in photosynthetic Dark-Adapted State .............. 91 performance. Light-Adapted State .............. 95 RELATIONSHIP BETWEEN PHOTOSYSTEM II BACKGROUND OPERATING EFFICIENCY, Following the observation by Kautsky & LINEAR ELECTRON FLUX, Hirsch (55) that changes in fluorescence in- AND CO2 ASSIMILATION ..... 96 duced by illumination of dark-adapted leaves FACTORS THAT DETERMINE are qualitatively correlated with changes in PHOTOSYSTEM II CO assimilation, it became evident that un- OPERATING EFFICIENCY .... 98 2 der some circumstances fluorescence emis- Photochemical Quenching ........ 99 sions in photosynthetic organisms could be Nonphotochemical Quenching.... 101 correlated to their photosynthetic rates (54, IMAGING OF 56, 77). Butler (21) developed a simple model FLUORESCENCE .............. 104 for photosystem II (PSII) photochemistry in which photochemistry competes with the pro- cesses of fluorescence and heat loss for excita- tion energy in the pigment antenna of PSII INTRODUCTION (Figure 1). This model followed from the Heat loss: occurs The use of chlorophyll a fluorescence mea- proposal that electron transfer from the re- when excitation energy within surements to examine photosynthetic perfor- action center chlorophyll of PSII (P680) to pigments is lost as mance and stress in algae and plants is now the primary quinone acceptor of PSII (QA) heat; often termed widespread in physiological and ecophysio- quenches fluorescence (28), a process termed nonradiative decay logical studies. This has come about owing photochemical quenching. Increases in the or thermal to the development of a sound understanding rate of heat loss result in nonphotochemical deactivation of the relationships between fluorescence pa- quenching of fluorescence. The model pre- Excitation energy: rameters and photosynthetic electron trans- dicts that PSII fluorescence emission could by Miami University of Ohio on 09/23/10. For personal use only. energy within a pigment molecule port in vivo and the commercial availability of be used to monitor changes in photochem- after a photon is a range of affordable, easy to use portable flu- istry, provided that the rate constants for flu- Annu. Rev. Plant Biol. 2008.59:89-113. Downloaded from www.annualreviews.org absorbed and orimeters. Fluorescence can be a very power- orescence and heat loss do not change (21). generates an excited ful tool to study photosynthetic performance, However, it is now well established that large state of the molecule especially when coupled with other noninva- changes can occur in the rate constant for heat QA: primary sive measurements such as absorption spec- loss from the PSII antenna (61, 65). Con- quinone electron troscopy, gas analyses, and infrared thermom- sequently, to estimate PSII photochemistry acceptor of PSII etry. This review examines how some key from fluorescence, it is essential to determine Photochemical fluorescence parameters can be used to as- the fluorescence quenching that results from quenching: results from using excitation sess photosynthetic performance in vivo and both photochemical and nonphotochemical energy within to identify possible causes of changes in pho- processes. photosystem II tosynthesis and plant performance; it is aimed Separation of fluorescence quenching into (PSII) to drive at plant biologists who seek to use fluores- photochemical and nonphotochemical com- electron transport cence as a tool in their research. However, ponents was first achieved by the addition from P680 to Q A the underlying theoretical bases of fluores- of 3-(3,4-dichlorophenyl)-1,1-dimethylurea 90 Baker ANRV342-PP59-05 ARI 27 March 2008 1:28 (DCMU) to intact chloroplasts and Chlorella Light cells at points throughout the fluorescence induction curve (64, 66). DCMU inhibits electron transfer from QA to the secondary quinone acceptor of PSII (QB), which results in a rapid reduction of QA and an increase Photosystem II in fluorescence as photochemical quenching is prevented. A slower increase in fluores- cence follows, which is associated with the decay of nonphotochemical quenching. Un- Photochemistry fortunately, this DCMU technique is not suit- e– Q able for analyzing fluorescence quenching in P680 A leaves owing to the slow and uneven pen- etration of DCMU into leaf tissues. Also, Chlorophyll Heat the irreversibility of the DCMU inhibition fluorescence of electron transport makes the technique Figure 1 unsuitable for continuous measurements on Simple model of the possible fate of light energy absorbed by photosystem individual leaves. However, maximal QA re- II (PSII). Light energy absorbed by chlorophylls associated with PSII can duction in leaves in the light can be achieved be used to drive photochemistry in which an electron (e−) is transferred by rapidly exposing leaves to a very large in- from the reaction center chlorophyll, P680, to the primary quinone crease in light (17). This light-addition tech- acceptor of PSII, QA. Alternatively, absorbed light energy can be lost from nique is used to quantitatively determine the PSII as chlorophyll fluorescence or heat. The processes of photochemistry, chlorophyll fluorescence, and heat loss are in direct competition for fraction of fluorescence quenching that is excitation energy. If the rate of one process increases the rates of the other attributable to photochemical and nonphoto- two will decrease. chemical quenching processes (18). The de- lated to the quantum yield of CO assimilation velopment of fluorimeters that use weak mod- 2 by the leaf, φ (37), thus allowing, under ulated measuring beams in which phase and CO2 certain conditions, the application of fluores- Nonphotochemical frequency decoding are used to detect fluo- cence measurements to provide a rapid, non- quenching: occurs rescence yield changes enabled the routine, when there is an destructive probe of CO assimilation. A list nondestructive, quantitative determination of 2 increase in the rate at of the fluorescence parameters used in this re- photochemical and nonphotochemical pro- which excitation view, their definitions, and comments on their cesses in leaves by the application of a brief energy within physiological relevance are given in Table 1. photosystem II is lost (less than 1 s) saturating flash of light suffi- by Miami University of Ohio on 09/23/10. For personal use only. as heat ciently intense as to maximally reduce the QA PHOTOSYSTEM II Quantum yield pool in the sample (26, 102). The value of the (quantum Annu. Rev. Plant Biol. 2008.59:89-113. Downloaded from www.annualreviews.org modulated technique is that it provides a con- PHOTOCHEMISTRY efficiency) of a tinuous measure of the relative quantum yield process: number of Dark-Adapted State of fluorescence (101). This technique was used molecules undergoing the to demonstrate that the quantum yield of PSII When a leaf is kept in the dark, QA becomes process divided by photochemistry of a leaf at a given actinic maximally oxidized and the PSII reaction cen- the number of light intensity can be estimated from the mod- ters are referred to as being ‘open’, i.e., capa- photons absorbed by ulated fluorescence yield prior to the appli- ble of performing photochemical reduction of the system cation of the saturating flash and the maxi- QA.
Load more

Recommended publications
  • Estimation of Chlorophyll Fluorescence at Different Scales
    sensors Review Estimation of Chlorophyll Fluorescence at Different Scales: A Review Zhuoya Ni 1, Qifeng Lu 1, Hongyuan Huo 2,* and Huili Zhang 3 1 Key Laboratory of Radiometric Calibration and Validation for Environment Satellites, National Satellite Meteorological Center, China Meteorological Administration, Beijing 100081, China 2 College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, China 3 Jiangxi Technical College Of Manufacturing, Nanchang 330095, China * Correspondence: [email protected]; Tel.: +86-010-6840-7273 Received: 24 April 2019; Accepted: 24 June 2019; Published: 8 July 2019 Abstract: Measuring chlorophyll fluorescence is a direct and non-destructive way to monitor vegetation. In this paper, the fluorescence retrieval methods from multiple scales, ranging from near the ground to the use of space-borne sensors, are analyzed and summarized in detail. At the leaf-scale, the chlorophyll fluorescence is measured using active and passive technology. Active remote sensing technology uses a fluorimeter to measure the chlorophyll fluorescence, and passive remote sensing technology mainly depends on the sun-induced chlorophyll fluorescence filling in the Fraunhofer lines or oxygen absorptions bands. Based on these retrieval principles, many retrieval methods have been developed, including the radiance-based methods and the reflectance-based methods near the ground, as well as physically and statistically-based methods that make use of satellite data. The advantages and disadvantages of different approaches for sun-induced chlorophyll fluorescence retrieval are compared and the key issues of the current sun-induced chlorophyll fluorescence retrieval algorithms are discussed. Finally, conclusions and key problems are proposed for the future research. Keywords: chlorophyll fluorescence; Fraunhofer lines; physically-based method; statistically-based method 1.
    [Show full text]
  • Using Chlorophyll Fluorescence to Study Photosynthesis*
    Using Chlorophyll Fluorescence to Study Photosynthesis* Yvan Fracheboud, Institute of Plant Sciences ETH, Universitätstrasse 2, CH-8092 Zürich. E-mail: [email protected]. * This article is not a review, but is a presentation explaining the basics and the applications of Chlorophyll fluorescence in Biology, and, is designed for beginning researchers and students. 1. Principles Each quantum of light absorbed by a chlorophyll molecule rises an electron from the ground state to an excited state. Upon de-excitation from a chlorophyll a molecule from excited state 1 to ground state, a small proportion (3-5% in vivo) of the excitation energy is dissipated as red fluorescence. The indicator function of chlorophyll fluorescence arises from the fact that fluorescence emission is complementary to alternative pathways of de-excitation which are primarily photochemistry and heat dissipation. Generally, fluorescence yield is highest when photochemistry and heat dissipation are lowest. Therefore, changes in the fluorescence yield reflect changes in photochemical efficiency and heat dissipation. Figure 1: Measurement of chlorophyll fluorescence from a maize leaf by the saturation pulse method using a PAM-2000 instrument (Walz). 1 A typical measurement on an intact leaf by the saturation pulse method is shown in Fig. 1. The plant was dark adapted for 20 min prior to the measurement. Upon the application of a saturating flash (8000 µmol m-2 s-1 for 1 s), fluorescence raises from the ground state value (Fo) to its maximum value, Fm. In this condition, QA, the first electron acceptor of PSII, is fully reduced. This allows the determination of the maximum quantum efficiency of photosystem II (PSII) primary photochemistry, given by Fv/Fm = (Fm-Fo)/Fm.
    [Show full text]
  • Chlorophyll a Fluorescence Advances in Photosynthesis and Respiration
    Chlorophyll a Fluorescence Advances in Photosynthesis and Respiration VOLUME 19 Series Editor : GOVINDJEE University of Illinois, Urbana, Illinois, U.S.A. Consulting Editors: Christine FOYER, Harpenden, U.K. Elisabeth GANTT, College Park, Maryland, U.S.A. John H.GOLBECK, University Park, Pennsylvania, U.S.A. Susan S. GOLDEN, College Station, Texas, U.S.A. Wolfgang JUNGE, Osnabrück, Germany Hartmut MICHEL, Frankfur t am Main, Germany Kirmiyuki SATOH, Okayama, Japan James Siedow, Durham, Nor th Carolina, U.S.A. The scope of our series, beginning with volume 11, reflects the concept that photosynthesis and respiration are intertwined with respect to both the protein complexes involved and to the entire bioenergetic machinery of all life. Advances in Photosynthesis and Respirationis a book series that provides a comprehensive and state-of-the-art account of research in photo- synthesis and respiration. Photosynthesis is the process by which higher plants, algae, and certain species of bacteria transform and store solar energy in the form of energy-rich organic molecules. These compounds are in turn used as the energy source for all growth and reproduction in these and almost all other organisms. As such, virtually all life on the planet ultimately depends on photosynthetic energy conversion. Respiration, which occurs in mitochondrial and bacterial membranes, utilizes energy present in organic molecules to fuel a wide range of metabolic reactions critical for cell growth and development. In addition, many photosynthetic organisms engage in energetically wasteful photorespiration that begins in the chloroplast with an oxygenation reaction catalyzed by the same enzyme responsible for capturing carbon dioxide in photosynthesis.
    [Show full text]
  • Use of in Vivo Chlorophyll Fluorescence to Estimate Photosynthetic Activity and Biomass Productivity in Microalgae Grown in Different Culture Systems
    Lat. Am. J. Aquat. Res., 41(5): 801-819,Chlorophyll 2013 fluorescence and biomass productivity in microalgae 801 DOI: 103856/vol41-issue5-fulltext-1 Review Use of in vivo chlorophyll fluorescence to estimate photosynthetic activity and biomass productivity in microalgae grown in different culture systems Félix L. Figueroa1, Celia G. Jerez1 & Nathalie Korbee1 1Departamento de Ecología, Facultad de Ciencias, Universidad de Málaga Campus Universitario de Teatinos s/n, E-29071 Málaga, España ABSTRACT. In vivo chlorophyll fluorescence associated to Photosystem II is being used to evaluate photosynthetic activity of microalgae grown in different types of photobioreactors; however, controversy on methodology is usual. Several recommendations on the use of chlorophyll fluorescence to estimate electron transport rate and productivity of microalgae grown in thin-layer cascade cultivators and methacrylate cylindrical vessels are included. Different methodologies related to the measure of photosynthetic activity in microalgae are discussed: (1) measurement of light absorption, (2) determination of electron transport rates versus irradiance and (3) use of simplified devices based on pulse amplitude modulated (PAM) fluorescence as Junior PAM or Pocket PAM with optical fiber and optical head as measuring units, respectively. Data comparisons of in vivo chlorophyll fluorescence by using these devices and other PAM fluorometers as Water- PAM in the microalga Chlorella sp. (Chlorophyta) are presented. Estimations of carbon production and productivity by transforming electron transport rate to gross photosynthetic rate (as oxygen evolution) using reported oxygen produced per photons absorbed values and carbon photosynthetic yield based on reported oxygen/carbon ratio are also shown. The limitation of ETR as estimator of photosynthetic and biomass productivity is discussed.
    [Show full text]
  • Bacillus Spp. Inoculation Improves Photosystem II Efficiency And
    Bacillus spp. inoculation improves photosystem II efficiency and enhances photosynthesis in pepper plants Blancka Yesenia Samaniego-Gámez1, René Garruña1*, José M. Tun-Suárez1, Jorge Kantun-Can1, Arturo Reyes-Ramírez1, and Lourdes Cervantes-Díaz2 ABSTRACT INTRODUCTION Bacillus is one of the main rhizobacteria to have been Plant growth promoting rhizobacteria (PGPR) are a diverse used as a study model for understanding many processes. group of bacteria that can be found in the rhizosphere, on root However, their impact on photosynthetic metabolism has surfaces and in association with roots (Ahemad and Kibret, 2014; been poorly studied. The aim of this study was to evaluate Lucas et al., 2014). Rhizobacteria are proficient at colonizing the physiological parameters of pepper (Capsicum chinense the root surface, surviving, multiplying and competing with Jacq.) plants inoculated with Bacillus spp. strains. Pepper other microbiota, at least for the time needed to express their seeds were inoculated with Bacillus cereus (K46 strain) plant growth promotion/protection activities, which can improve and Bacillus spp. (M9 strain; a mixture of B. subtilis and plant fitness by different mechanisms (García-Cristobal et B. amyloliquefaciens), chlorophyll fluorescence and gas al., 2015). Directly, the presence of rhizobacteria can cause exchange were evaluated. The ANOVA (P ≤ 0.05) showed modifications to plant metabolism. Examples include N fixation, that the maximum photochemical quantum yield of phosphate solubilization, Fe sequestration, and cytokinin, gibberellin, indoleacetic acid and ethylene production (Lucas photosystem II (PSII) (Fv/Fm) in plants inoculated with the M9 strain (0.784) increased with respect to other treatments et al., 2014). Indirectly, the presence of rhizobacteria promotes (K46: 0.744 and Control: 0.739).
    [Show full text]
  • Rate-Limiting Steps in the Dark-To-Light Transition of Photosystem II
    www.nature.com/scientificreports OPEN Rate-limiting steps in the dark-to- light transition of Photosystem II - revealed by chlorophyll-a Received: 29 June 2017 Accepted: 31 January 2018 fuorescence induction Published: xx xx xxxx Melinda Magyar1, Gábor Sipka1, László Kovács1, Bettina Ughy1, Qingjun Zhu2, Guangye Han2, Vladimír Špunda3,4, Petar H. Lambrev1, Jian-Ren Shen2,5 & Győző Garab1,3 Photosystem II (PSII) catalyses the photoinduced oxygen evolution and, by producing reducing equivalents drives, in concert with PSI, the conversion of carbon dioxide to sugars. Our knowledge about the architecture of the reaction centre (RC) complex and the mechanisms of charge separation and stabilisation is well advanced. However, our understanding of the processes associated with the functioning of RC is incomplete: the photochemical activity of PSII is routinely monitored by chlorophyll-a fuorescence induction but the presently available data are not free of controversy. In this work, we examined the nature of gradual fuorescence rise of PSII elicited by trains of single- turnover saturating fashes (STSFs) in the presence of a PSII inhibitor, permitting only one stable charge separation. We show that a substantial part of the fuorescence rise originates from light- induced processes that occur after the stabilisation of charge separation, induced by the frst STSF; the temperature-dependent relaxation characteristics suggest the involvement of conformational changes in the additional rise. In experiments using double fashes with variable waiting times (∆τ) between them, we found that no rise could be induced with zero or short ∆τ, the value of which depended on the temperature - revealing a previously unknown rate-limiting step in PSII.
    [Show full text]
  • Leaf Orientation, Photorespiration and Xanthophyll Cycle Protect Young Soybean Leaves Against High Irradiance in field
    Environmental and Experimental Botany 55 (2006) 87–96 Leaf orientation, photorespiration and xanthophyll cycle protect young soybean leaves against high irradiance in field Chuang-Dao Jiang a, Hui-Yuan Gao b,∗,QiZoub, Gao-Ming Jiang a, Ling-Hao Li a a Laboratory of Quantitative Vegetation Ecology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China b Department of Plant Science, Shandong Agricultural University, Taian 271018, PR China Accepted 6 October 2004 Abstract In order to fully understand the adaptive strategies of young leaves in performing photosynthesis under high irradiance, leaf orientation, chloroplast pigments, gas exchange, as well as chlorophyll a fluorescence kinetics were explored in soybean plants. The chlorophyll content and photosynthesis in young leaves were much lower than that in fully expanded leaves. Both young and fully expanded leaves exhibited down-regulation of the maximum quantum yield (FV/FM) at noon in their natural position, no more serious down-regulation being observed in young leaves. However, when restraining leaf movement and vertically exposing −2 −1 the leaves to 1200 ␮mol m s irradiance, more pronounced down-regulation of FV/FM was observed in young leaves; and the actual photosystem II (PS II) efficiency (ФPSII) drastically decreased with the significant enhancement of non-photochemical −2 −1 quenching (NPQ) and ‘High energy’ quenching (qE) in young leaves. Under irradiance of 1200 ␮mol m s , photorespiration (Pr) in young leaves measured by gas exchange were obviously lower, whereas the ratio of photorespiration/gross photosynthetic rate (Pr/Pg) were higher than that in fully expanded leaves. Compared with fully expanded leaves, young leaves exhibited higher xanthophyll pool and a much higher level of de-epoxidation components when exposure to high irradiance.
    [Show full text]
  • Quantifying Chlorophyll Fluorescence Parameters from Hyperspectral Reflectance at the Leaf Scale Under Various Nitrogen Treatment Regimes in Winter Wheat
    remote sensing Article Quantifying Chlorophyll Fluorescence Parameters from Hyperspectral Reflectance at the Leaf Scale under Various Nitrogen Treatment Regimes in Winter Wheat Min Jia 1,2,3,4, Dong Li 1,2,3,4, Roberto Colombo 5, Ying Wang 1,2,3,4, Xue Wang 1,2,3,4, Tao Cheng 1,2,3,4 , Yan Zhu 1,2,3,4 , Xia Yao 1,2,3,4,*, Changjun Xu 6, Geli Ouer 6, Hongying Li 6 and Chaokun Zhang 6 1 National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; [email protected] (M.J.); [email protected] (D.L.); [email protected] (Y.W.); [email protected] (X.W.); [email protected] (T.C.); [email protected] (Y.Z.) 2 Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Nanjing 210095, China 3 Jiangsu Key Laboratory for Information Agriculture, Nanjing 210095, China 4 Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing 210095, China 5 Remote Sensing of Environmental Dynamics Laboratory, Department of Earth and Environmental Science (DISAT), Università di Milano-Bicocca, Piazza della Scienza 1, 20126 Milan, Italy; [email protected] 6 Qinghai Basic Geographic Information Center, Qinghai 810000, China; [email protected] (C.X.); [email protected] (G.O.); fl[email protected] (H.L.); [email protected] (C.Z.) * Correspondence: [email protected]; Tel.: +86-25-84396565; Fax: +86-25-84396672 Received: 8 October 2019; Accepted: 23 November 2019; Published: 29 November 2019 Abstract: Chlorophyll fluorescence (ChlF) parameters, especially the quantum efficiency of photosystem II (PSII) in dark- and light-adapted conditions (Fv/Fm and Fv’/Fm’), have been used extensively to indicate photosynthetic activity, physiological function, as well as healthy and early stress conditions.
    [Show full text]
  • Coral Symbiotic Algae Calcify Ex Hospite in Partnership with Bacteria
    Coral symbiotic algae calcify ex hospite in partnership with bacteria Jörg C. Frommleta,b,1, Maria L. Sousaa,b, Artur Alvesa,b, Sandra I. Vieirac,d,e, David J. Suggettf, and João Serôdioa,b aDepartment of Biology, bCenter for Environmental and Marine Studies (CESAM), cAutonomous Section of Health Sciences, dCenter for Cell Biology, and eInstitute for Biomedicine, Santiago Campus, University of Aveiro, 3810-193 Aveiro, Portugal; and fFunctional Plant Biology & Climate Change Cluster, University of Technology Sydney, Broadway, NSW 2007, Australia Edited by Tom M. Fenchel, University of Copenhagen, Helsingor, Denmark, and approved March 25, 2015 (received for review November 2, 2014) Dinoflagellates of the genus Symbiodinium are commonly recog- carbonate formation (14–19). Several metabolic pathways are nized as invertebrate endosymbionts that are of central impor- known to drive microbially induced calcification, but oxygenic tance for the functioning of coral reef ecosystems. However, the photosynthesis is considered the most significant (14–17, 19). endosymbiotic phase within Symbiodinium life history is inherently Cyanobacteria and to a much lesser extent diatoms, as well as tied to a more cryptic free-living (ex hospite) phase that remains brown, green, and red microalgae, have been identified as the largely unexplored. Here we show that free-living Symbiodinium key phototrophic partners within these calcifying microbial–algal spp. in culture commonly form calcifying bacterial–algal communities communities (14–17, 19). Dinoflagellates have been found within that produce aragonitic spherulites and encase the dinoflagellates calcifying communities (20, 21), but whether they actively drive as endolithic cells. This process is driven by Symbiodinium photo- calcification has never been addressed.
    [Show full text]
  • Estimating Chlorophyll Fluorescence Parameters Using the Joint Fraunhofer Line Depth and Laser-Induced Saturation Pulse (FLD-LISP) Method in Different Plant Species
    remote sensing Article Estimating Chlorophyll Fluorescence Parameters Using the Joint Fraunhofer Line Depth and Laser-Induced Saturation Pulse (FLD-LISP) Method in Different Plant Species Parinaz Rahimzadeh-Bajgiran 1,2, Bayaer Tubuxin 1 and Kenji Omasa 1,* 1 Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan; [email protected] (P.R.-B.); [email protected] (B.T.) 2 School of Forest Resources, University of Maine, 5755 Nutting Hall, Orono, ME 04469, USA * Correspondence: [email protected]; Tel.: +81-3-5841-8101 Academic Editors: Jose Moreno and Prasad S. Thenkabail Received: 5 January 2017; Accepted: 9 June 2017; Published: 13 June 2017 Abstract: A comprehensive evaluation of the recently developed Fraunhofer line depth (FLD) and laser-induced saturation pulse (FLD-LISP) method was conducted to measure chlorophyll fluorescence (ChlF) parameters of the quantum yield of photosystem II (FPSII), non-photochemical quenching (NPQ), and the photosystem II-based electron transport rate (ETR) in three plant species including paprika (C3 plant), maize (C4 plant), and pachira (C3 plant). First, the relationships between photosynthetic photon flux density (PPFD) and ChlF parameters retrieved using FLD-LISP and the pulse amplitude-modulated (PAM) methods were analyzed for all three species. Then the relationships between ChlF parameters measured using FLD-LISP and PAM were evaluated for the plants in different growth stages of leaves from mature to aging conditions. The relationships of ChlF parameters/PPFD were similar in both FLD-LISP and PAM methods in all plant species. FPSII showed a linear relationship with PPFD in all three species whereas NPQ was found to be linearly related to PPFD in paprika and maize, but not for pachira.
    [Show full text]
  • Two Functionally Distinct Forms of the Photosystem II Reaction-Center Protein Dl in the Cyanobacterium Synechococcus Sp
    Proc. Natl. Acad. Sci. USA Vol. 90, pp. 11985-11989, December 1993 Biochemistry Two functionally distinct forms of the photosystem II reaction-center protein Dl in the cyanobacterium Synechococcus sp. PCC 7942 (chlorophyll fluorescence/photosynthesis/protein turnover) ADRIAN K. CLARKE*, VAUGHAN M. HuRRY, PETTER GUSTAFSSON, AND GUNNAR OQUIST Department of Plant Physiology, University of Ume&, Ume& S-901 87, Sweden Communicated by Daniel J. Arnon, September 16, 1993 ABSTRACT The cyanobacterium Synechococcus sp. PCC form I ofthe Dl polypeptide (Dl:1), whereas the second form 7942 possesses a smallpsbA multigene family that codes for two (D1:2) is encoded by both the psbAII and psbAIII genes (4). distinct forms ofthe photosystem II reaction-center protein Dl The two forms of Dl differ in only 25 of the total 360 amino (D1:1 and D1:2). We showed previously that the normally acids, and 12 of these differences occur in the first 16 amino predominant Dl form (D1:1) was rapidly replaced with the acids and 7 within the putative transmembrane helices II and alternative D1:2 when cells adapted to a photon irradiance of III (4). As yet, no distinct functional difference between Dl:1 50 pmol mM2's'1 are shifted to 500 ,umol m-2 s-1 and that this and D1:2 has been reported. interchange was readily reversible once cells were allowed to The level of expression for the individual psbA genes in recover under the original growth conditions. By using thepsbA Synechococcus sp. PCC 7942 varies considerably with dif- inactivation mutants R2S2C3 and R2K1 (which synthesize only ferent photon irradiance.
    [Show full text]
  • Response of Photosynthesis and Chlorophyll Fluorescence Parameters of Castanopsis Kawakamii Seedlings to Forest Gaps
    Article Response of Photosynthesis and Chlorophyll Fluorescence Parameters of Castanopsis kawakamii Seedlings to Forest Gaps Zhong-sheng He 1,2,3 , Rong Tang 1, Meng-jia Li 1,2,3, Meng-ran Jin 1,2,3, Cong Xin 1,2,3, Jin-fu Liu 1,2,3,* and Wei Hong 1 1 College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350002, China; [email protected] (Z.-s.H.); [email protected] (R.T.); [email protected] (M.-j.L.); [email protected] (M.-r.J.); [email protected] (C.X.); [email protected] (W.H.) 2 Key Lab of Ecology and Resources Statistics of Fujian Colleges, Fuzhou 350002, China 3 Cross–Strait Nature Research Center, Fuzhou 350002, China * Correspondence: [email protected]; Tel.: +86-153-5911-9967 Received: 28 November 2019; Accepted: 20 December 2019; Published: 22 December 2019 Abstract: Light is a major environmental factor limiting the growth and survival of plants. The heterogeneity of the light environment after gap formation in forest influences the leaf chlorophyll contents, net photosynthetic rate (Pn), and chlorophyll fluorescence, thus influencing the growth and regeneration of Castanopsis kawakamii seedlings. The aim of this study was to explore the effects of weak light on the photosynthetic physiology of C. kawakamii seedlings in forest gaps and non-gaps. The results showed that (1) the contents of chlorophyll a (Chl-a), chlorophyll b (Chl-b), and total chlorophyll (Chl-T) in forest gaps were lower than in non-gaps. Seedlings tended to increase chlorophyll content to absorb light energy to adapt to low light intensity in non-gap environments.
    [Show full text]