Seeing Is Believing

L. Nedbal Govindjee

Photosynthetica 2000, 38(4):481-482 | DOI: 10.1023/A:1012485018944

Imaging of the Blue, Green, and Red Fluorescence Emission of Plants: An Overview

C. Buschmann, G. Langsdorf, H.K. Lichtenthaler

Photosynthetica 2000, 38(4):483-491 | DOI: 10.1023/A:1012440903014

An overview is given on the fluorescence imaging of plants. Emphasis is laid upon multispectral fluorescence imaging in the maxima of the fluorescence emission bands of leaves, i.e., in the blue (440 nm), green (520 nm), red (690 nm), and far-red (740 nm) spectral regions. Details on the origin of these four fluorescence bands are presented including emitting substances and emitting sites within a leaf tissue. Blue-green fluorescence derives from ferulic acids covalently bound to cell walls, and the red and far-red fluorescence comes from chlorophyll (Chl) a in the chloroplasts of green mesophyll cells. The fluorescence intensities are...

Scheper, T. (Ed.): Advances in Biochemical Engineering Biotechnology: Bioprocess and Algae Reactor Technology, Apoptosis

V. Zachleder

Photosynthetica 2000, 38(4):492 | DOI: 10.1023/A:1012438229847

Inner Structure of Intact Chloroplasts Observed by a Low Temperature Laser Scanning Microscope

F. Vácha, M. Vácha, L. Bumba, K. Hashizume, T. Tani

Photosynthetica 2000, 38(4):493-496 | DOI: 10.1023/A:1012492919852

Inner structure of isolated intact chloroplasts was observed for the first time by a method of laser scanning microscopy at the temperature of liquid nitrogen at 77 K. The microscope, based on gradient index optics, has a maximum resolution of 440 nm at the wavelength of 650 nm. Chloroplasts were excited into the Q-band of chlorophyll b by a krypton laser line at 647.6 nm and fluorescence was detected using two different interference filters. The 680 nm interference filter detects the regions where photosystem (PS) 2 mainly occurs, the 730 nm interference filter detects domains with predominant location of PS1. Since PS1 occurs mainly in stroma...

Identification of Photosynthetic Mutants of Arabidopsis by Automatic Screening for Altered Effective Quantum Yield of Photosystem 2

C. Varotto, P. Pesaresi, D. Maiwald, J. Kurth, F. Salamini, D. Leister

Photosynthetica 2000, 38(4):497-504 | DOI: 10.1023/A:1012445020761

Quantification of chlorophyll (Chl) fluorescence is a versatile tool for analysing the photosynthetic performance of plants in a non-intrusive manner. A pulse-amplitude modulated fluorometer was combined with a CNC router for the automated measurement of the effective quantum yield of photosystem 2 (Φ₂) of Arabidopsis thaliana plants. About 90 000 individual plants representing 7 500 lines derived from En-transposon and T-DNA mutagenised Arabidopsis populations were screened for mutants with altered Φ₂. Forty-eight recessive Φ₂ mutations were identified of which most exhibit also altered...

Analysis of Photosynthetic Activity at the Leaf and Canopy Levels from Reflectance Measurements: A Case Study

M. Méthy

Photosynthetica 2000, 38(4):505-512 | DOI: 10.1023/A:1012449104831

The photochemical reflectance index (PRI), based on reflectance signatures at 531 and 570 nm, and associated with xanthophyll pigment inter-conversion and related thylakoid energisation, was evaluated as an indicator of photosynthetic function in a Mediterranean holm oak (Quercus ilex L.) coppice. The chlorophyll fluorescence pulse-amplitude-modulation and the eddy correlation techniques were used to estimate the photosystem 2 photochemical efficiency of leaves and the CO₂ flux over the canopy, respectively. The reflectance and fluorescence techniques yielded identical estimates of the photosynthetic activity in leaves exposed to...

Analysis of Qualitative Contribution of Assimilatory and Non-Assimilatory De-Excitation Processes to Adaptation of Photosynthetic Apparatus of Barley Plants to High Irradiance

I. Kurasová, M. Čajánek, J. Kalina, V. Špunda

Photosynthetica 2000, 38(4):513-519 | DOI: 10.1023/A:1012401221669

The adaptation of barley (Hordeum vulgare L. cv. Akcent) plants to low (LI, 50 µmol m^-2 s^-1) and high (HI, 1000 µmol m^-2 s^-1) growth irradiances was studied using the simultaneous measurements of the photosynthetic oxygen evolution and chlorophyll a (Chl a) fluorescence at room temperature. If measured under ambient CO₂ concentration, neither increase of the oxygen evolution rate (P) nor enhancement of non-radiative dissipation of the absorbed excitation energy within photosystem 2 (PS2) (determined as non-photochemical quenching of Chl a fluorescence,...

Singhal, G.S., Renger, G., Sopory, S.K., Irrgang, K.-D., Govindjee (Ed.): Concepts in Photobiology. Photosynthesis and Photomorphogenesis

D. Sofrová

Photosynthetica 2000, 38(4):520 | DOI: 10.1023/A:1012490213917

Measurement of Differences in Red Chlorophyll Fluorescence and Photosynthetic Activity between Sun and Shade Leaves by Fluorescence Imaging

H.K. Lichtenthaler, F. Babani, G. Langsdorf, C. Buschmann

Photosynthetica 2000, 38(4):521-529 | DOI: 10.1023/A:1012453205740

With a flash-lamp chlorophyll (Chl) fluorescence imaging system (FL-FIS) the photosynthetic activity of several thousand image points of intact shade and sun leaves of beech were screened in a non-destructive way within a few seconds. The photosynthetic activity was determined via imaging the Chl fluorescence at maximum F_p and steady state fluorescence F_s of the induction kinetics (Kautsky effect) and by a subsequent determination of the images of the fluorescence decrease ratio R_Fd and the ratio F_p/F_s. Both fluorescence ratios are linearly correlated to the photosynthetic CO₂...

Raghavendra, A.S. (Ed.): Photosynthesis. A Comprehensive Treatise

J. Šantrůček

Photosynthetica 2000, 38(4):530 | DOI: 10.1023/A:1012434128938

Heterogeneity of Chlorophyll Fluorescence over Thalli of Several Foliose Macrolichens Exposed to Adverse Environmental Factors: Interspecific Differences as Related to Thallus Hydration and High Irradiance

M. Barták, J. Hájek, J. Gloser

Photosynthetica 2000, 38(4):531-537 | DOI: 10.1023/A:1012405306648

Spatial heterogeneity of chlorophyll (Chl) fluorescence over thalli of three foliose lichen species was studied using Chl fluorescence imaging (CFI) and slow Chl fluorescence kinetics supplemented with quenching analysis. CFI values indicated species-specific differences in location of the most physiologically active zones within fully hydrated thalli: marginal thallus parts (Hypogymnia physodes), central part and close-to-umbilicus spots (Lasallia pustulata), and irregulary-distributed zones within thallus (Umbilicaria hirsuta). During gradual desiccation of lichen thalli, decrease in Chl fluorescence parameters (F_O...

James, C.: Errors in Language Learning and Use. Exploring Error Analysis

Z. Šesták

Photosynthetica 2000, 38(4):538 | DOI: 10.1023/A:1012430028030

Reuter, B.: Taschenwörterbuch der Biochemie. Deutsch - Englisch, Englisch - Deutsch. Pocket Dictionary of Biochemistry. English - German, German - English

Z. Šesták

Photosynthetica 2000, 38(4):538 | DOI: 10.1023/A:1012482012100

Multicolour Fluorescence Imaging of Sugar Beet Leaves with Different Nitrogen Status by Flash Lamp UV-Excitation

G. Langsdorf, C. Buschmann, M. Sowinska, F. Babani, M. Mokry, F. Timmermann, H.K. Lichtenthaler

Photosynthetica 2000, 38(4):539-551 | DOI: 10.1023/A:1012409423487

Fluorescence images of leaves of sugar beet plants (Beta vulgaris L. cv. Patricia) grown on an experimental field with different fertilisation doses of nitrogen [0, 3, 6, 9, 12, 15 g(N) m^-2] were taken, applying a new multicolour flash-lamp fluorescence imaging system (FL-FIS). Fluorescence was excited by the UV-range (280-400 nm, λ_max = 340 nm) of a pulsed Xenon lamp. The images were acquired successively in the four fluorescence bands of leaves near 440, 520, 690, and 740 nm (F₄₄₀, F₅₂₀, F₆₉₀, F₇₄₀) by means of a CCD-camera. Parallel measurements were performed to characterise...

Veit, W.: The Music of Sunlight

D. Walker

Photosynthetica 2000, 38(4):552 | DOI: 10.1023/A:1012446431664

Vonshak, A. (Ed.): Spirulina platensis (Arthrospira). Physiology, Cell Biology and Biotechnology

J. Lukavský

Photosynthetica 2000, 38(4):552 | DOI: 10.1023/A:1012498515734

A Microscope for Two-Dimensional Measurements of In Vivo Chlorophyll Fluorescence Kinetics Using Pulsed Measuring Radiation, Continuous Actinic Radiation, and Saturating Flashes

H. Küpper, I. Šetlík, M. Trtílek, L. Nedbal

Photosynthetica 2000, 38(4):553-570 | DOI: 10.1023/A:1012461407557

Transients of chlorophyll fluorescence in photosynthetic objects are often measured using short pulses of exciting radiation, which has recently been employed to capture kinetic images of fluorescence at the macroscopic level. Here we describe an instrument introducing this principle to recording of two dimensional fluorescence transients in microscopic objects. A modified fluorescence microscope is equipped with a CCD camera intensified by a micro-channel plate image amplifier. The microscopic field is irradiated simultaneously by three types of radiation: actinic radiation, saturating flashes, and pulsed measuring radiation. The measuring pulses...

Postharvest Imaging of Chlorophyll Fluorescence from Lemons Can Be Used to Predict Fruit Quality

L. Nedbal, J. Soukupová, J. Whitmarsh, M. Trtílek

Photosynthetica 2000, 38(4):571-579 | DOI: 10.1023/A:1012413524395

We demonstrate the feasibility of assaying and predicting post-harvest damage in lemons by monitoring chlorophyll (Chl) fluorescence. Fruit quality was assayed using a commercial instrument that determines photosynthetic performance by imaging Chl fluorescence parameters under different irradiances. Images of Chl fluorescence from individual lemons reveal that photosynthesis is active throughout the post-harvest ripening process. Because photosynthesis is highly sensitive to biotic and abiotic stress, variations in Chl fluorescence parameters over the surface of a lemon fruit can be used to predict areas that will eventually exhibit visible damage....

Thomas, P.A.: Trees: Their Natural History

J. Jeník

Photosynthetica 2000, 38(4):580 | DOI: 10.1023/A:1012442330755

Fluorescence Lifetime Imaging (FLI) in Real-Time - a New Technique in Photosynthesis Research

O. Holub, M.J. Seufferheld, C. Gohlke, Govindjee, R.M. Clegg

Photosynthetica 2000, 38(4):581-599 | DOI: 10.1023/A:1012465508465

We describe an instrument that allows the rapid measurement of fluorescence lifetime-resolved images of leaves as well as sub-cellular structures of intact plants or single cells of algae. Lifetime and intensity fluorescence images can be acquired and displayed in real time (up to 55 lifetime-resolved images per s). Our imaging technique therefore allows rapid measurements that are necessary to determine the fluorescence lifetimes at the maximum (P level) fluorescence following initial illumination during the chlorophyll (Chl) a fluorescence transient (induction) in photosynthetic organisms. We demonstrate the application of this new instrument...

Walker, D.A.: Like Clockwork - An Unfinished Story

Z. Šesták

Photosynthetica 2000, 38(4):600 | DOI: 10.1023/A:1012494314826

A Phycoerythrin-Allophycocyanin Complex from the Intact Phycobilisomes of the Marine Red Alga Polysiphonia Urceolata

Li Sun, Shumei Wang

Photosynthetica 2000, 38(4):601-605 | DOI: 10.1023/A:1012417725304

A phycoerythrin-allophycocyanin (PE-AP) complex was obtained from intact phycobilisomes of the marine red alga Polysiphonia urceolata. Study of spectral properties and polypeptide components showed that the complex contains PE, phycocyanin, AP, and higher proportional linker proteins of the four groups present in intact phycobilisomes.

Oxford Dictionary of Biochemistry and Molecular Biology. Revised Edition

Z. Šesták

Photosynthetica 2000, 38(4):606 | DOI: 10.1023/A:1012450632573

Photosystem 2 Efficiency and Thylakoid Protein Pattern in DCMU-Treated Wheat Seedlings during Senescence

N. Nedunchezhian, K. Muthuchelian, M. Bertamini

Photosynthetica 2000, 38(4):607-614 | DOI: 10.1023/A:1012469709374

Changes in various components of photosynthetic apparatus during the 6-d dark incubation at 25 °C of detached control and DCMU-treated Triticum aestivum L. leaves were examined. The rate of photosystem 2 (PS2) activity was decreased with increase of the time of dark incubation in control leaves. In contrast to this, DCMU-treated leaves demonstrated high stability by slowing down the inactivation processes. Diphenyl carbazide and NH₂OH restored the PS2 activity more in control leaves than in DCMU-treated leaves. Mn²⁺ failed to restore the PS2 activity in both control and DCMU-treated samples. Similar results were obtained...

Photosynthesis in Two Wheat Cultivars Differing in Salt Susceptibility

F. El-Shintinawy

Photosynthetica 2000, 38(4):615-620 | DOI: 10.1023/A:1012421826212

Salinised (150 mM NaCl for 15 d) roots excised from salt sensitive wheat cultivar Giza 163 showed about 15-fold increase in the ratio of Na/K while salt tolerant Sakha 92 exhibited only 7.5-fold increase compared to their control ratios. Root ratio of saturated/unsaturated fatty acids was stimulated twice in the sensitive cultivar versus 1.7-fold increase in the tolerant ones. Salinity enhanced greatly the accumulation of spermine (Spm) and spermidine (Spd) contents associated with a decrease in putrescine (Put) content in both wheat cultivars. Higher ratios of Spm+Spd/Put associated with lower content of proline and low ethylene evolution were...

Acclimation of Photosystem 2 Function of Norway Spruce Induced during First Season under Elevated CO2 in Lamellar Domes

J. Kalina, M. Čajánek, I. Kurasová, V. Špunda, J. Vrána, M.V. Marek

Photosynthetica 2000, 38(4):621-627 | DOI: 10.1023/A:1012473810283

Since July 28^th, 1997 the two experimental mini-stands of young Norway spruce [Picea abies (L.) Karst.] have been grown in lamellar domes at ambient (AC) and elevated concentrations of CO₂ [EC, i.e., ambient + 350 µmol(CO₂) mol^-1]. Before the start of exposure to EC (June 1997) the dependencies of photosystem 2 (PS2) quantum yield (Y) on irradiance, estimating the efficiency of PPFD utilisation in PS2 photochemistry, were the same for AC and EC shoots. After one month of EC simulation (August 1997), Y values were higher for EC needles as compared with the AC ones (by 1-42 %), whereas two...

Valiela, I.: Doing Science. Design, Analysis, and Communication of Scientific Research

Z. Šesták

Photosynthetica 2000, 38(4):628 | DOI: 10.1023/A:1012486113009

Growth, Stomatal Conductance, Photosynthetic Rate, Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase and Phosphoenolpyruvate Carboxylase Activities during Rooting and Acclimatisation of Rosa Hybrida Plantlets

C. Genoud, H. Sallanon, A. Hitmi, Y. Maziere, A. Coudret

Photosynthetica 2000, 38(4):629-634 | DOI: 10.1023/A:1012425927121

The rooting of shoots of micropropagated Rosa hybrida cv. Madame Delbard was conducted on MS medium with 30 kg m^-3 sucrose or on hydroponic medium (containing less mineral salts), under higher photosynthetic photon flux density (PPFD) (100 in comparison with 45 µmol m^-2 s^-1) and flushed by ambient air [AC, 340 µmol(CO₂) mol^-1] or by CO₂-enriched air (EC, 2 500 µmol mol^-1) and lower relative humidity (80-90 % vs. 96-99 %). This cultivation led to plantlets with longer roots and adventitious root formation. Net photosynthetic rate and ribulose-1,5-bisphosphate...

Thermoluminescence Investigation of Low Temperature Stress in Maize

T. Janda, G. Szalai, E. Páldi

Photosynthetica 2000, 38(4):635-639 | DOI: 10.1023/A:1012477911191

The thermoluminescence (TL) emission of photosynthesising materials originates from the recombination of charge pairs created by a previous excitation. Using a recently described TL set-up the effect of chilling stress on TL bands occurring at positive temperatures (AG, B, and HTL) was investigated in intact leaves. The far-red irradiation of leaves at low, but non-freezing temperatures induced a TL band peaking at around 40-45 °C (AG band), together with a B band peaking between 20 and 35 °C. Low temperature stress first caused a downshift and a temporary increase in the AG band after 4 h at 0 °C in the light, then a decrease in the AG and B TL bands...