Changes in the chlorophyll fluorescence characteristics of chloroplasts from intact pumpkin cotyledons, caused by organ excision and kinetin treatment

L.M. Behera, N.K. Choudhury

Photosynthetica 1996, 34(2):161-168 | DOI: 10.1023/A:1006828221038

The chlorophyll (Chl) fluorescence emission as well as excitation and polarization characteristics of chloroplasts from intact cotyledons were determined in pumpkin seedlings after removal of one cotyledon (co-cotyledon) or apical bud or primary root, or after kinetin treatment of derooted seedlings. Qualitatively, the fluorescence emission and excitation spectra of chloroplasts were similar. The fluorescence emission spectra showed a maximum at 685 (F685) and a hump at 735 nm (F735), whereas the excitation spectra showed peaks at 439, 471, 485, and 676 nm. The fluorescence intensities at F685 and F735 differed in various groups of seedlings, as indicated...

Short-term effects of aluminium at alkaline pH on the structure and function of the photosynthetic apparatus

M. Moustakas, E.P. Eleftheriou, G. Ouzounidou

Photosynthetica 1996, 34(2):169-177 | DOI: 10.1023/A:1006880205108

A 24 h exposure of the salt-tolerant grass Thinopyrum bessarabicum (Savul. and Rayss) A. Love seedlings to 1 mM aluminium (Al) in nutrient solution at pH of 9.0 resulted in a significant reduction of the biomass. In control samples the mesophyll chloroplasts exhibited the usual lens shape with most grana arranged in straight or slightly curving lines, and only 6.5 % of the grana were out of order. In Al-treated plants the mesophyll chloroplasts displayed a slightly distorted shape and distended size with most grana arranged in bow-like lines, while in the central region of the organelle as many as 26.7 % of the grana were independent and out of order...

Baker, N.R. (ed.): Photosynthesis and the Environment

Z. Šesták

Photosynthetica 1996, 34(2):178 | DOI: 10.1023/A:1006865229215

Effects of copper on the growth, photosynthesis and nutrient concentrations of Phaseolus plants

C.M. Cook, A. Kostidou, E. Vardaka, T. Lanaras

Photosynthetica 1996, 34(2):179-193 | DOI: 10.1023/A:1006832321946

Bean plants (Phaseolus vulgaris L. var. Zargana Kavala) were grown under conditions of increasing Cu concentrations in the growth medium (0.5-160.5 µM). Generally, the Cu concentrations between 0.5-1.5 µM were deficient, 1.5-10.5 µM were optimal, and 10.5-160.5 µM were toxic to plant growth. The Cu toxicity was associated with marked increases in plant tissue Cu concentrations. Under the Cu-deficient and optimal growth conditions, Cu was located primarily in the leaves. Under Cu toxicity, it was primarily sequestered in the roots. With increasing Cu in the growth medium, there was a positive correlation between Cu concentrations...

Jennings, R.C., Zucchelli, G., Ghetti, F., Colombetti, G. (ed.): Light as an Energy Source and Information Carrier in Plant Physiology

Z. Šesták

Photosynthetica 1996, 34(2):194 | DOI: 10.1023/A:1006817313285

Stomatal frequency of Quercus myrsinaefolia grown under different irradiances

A. Furukawa

Photosynthetica 1996, 34(2):195-199 | DOI: 10.1023/A:1006884306017

Stomatal and epidermal cell frequencies and leaf area were measured in leaves of Quercus myrsinaefolia grown in the field under different relative photon flux density (PFD), which was the ratio of integrated PFD at the leaf surface to that at an open site. Leaf area showed a linear relationship with the relative PFD. Stomatal and epidermal cell frequencies increased with increasing relative PFD. Numbers of stomata and epidermal cells per leaf, and stomatal index (ratio of stomatal number to epidermal cell number) increased with increasing relative PFD.

Mohanty, P. (ed.): Special Issue on Cyanobacterial Photosynthesis: Concepts and Applications

Z. Šesták

Photosynthetica 1996, 34(2):200 | DOI: 10.1023/A:1006869430124

Changes of the photosystem 2 activity and thylakoid proteins in spruce seedlings during water stress

P.A.K. Eastman, A. Rashid, E.L. Camm

Photosynthetica 1996, 34(2):201-210 | DOI: 10.1023/A:1006836422855

We subjected spruce [Picea glauca (Moench) Voss × P. engelmanni Parry hybrid complex] seedlings to a severe water stress (shoot water potential ≤-3.5 MPa) to permit assessment of stress effects on photosystem 2 (PS2) in isolated photosynthetic membranes. The thylakoids and Triton-treated membranes isolated from stressed seedlings showed declines in O2-evolving capacity (H2O → 2,6-dichloro-p-benzoquinone, DCBQ) and electron transport activity (H2O → 2,6-dichlorophenol indophenol, DCIP). A partial restoration of O2-evolution by adding CaCl2 suggested an effect of water stress on the oxygen-enhancing extrinsic (OEE) polypeptides. Water stress...

Proteolytic degradation of barley ribulose-1,5-bisphosphate carboxylase/oxygenase and recognition of the fragments by monoclonal antibodies

K. Demirevska-Kepova, L. Simova-Stoilova, S. Kyurkchiev

Photosynthetica 1996, 34(2):211-218 | DOI: 10.1023/A:1006888506925

Limited proteolysis of barley ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) was effected by treatments with trypsin and Staphylococcus aureus strain V8 protease. Treatment of native RuBPCO with proteases resulted in the degradation of the large subunit (LS) of the enzyme. Trypsin cleaved three fragments from the LS but the S. aureus strain V8 protease cleaved only one. The small subunit (SS) was not affected. In the presence of 0.5 % sodium dodecyl sulfate, RuBPCO degraded into several fragments; some of them were fairly stable. Monoclonal antibodies (Mabs) against barley RuBPCO were applied in immunoblotting analysis to distinguish which...

The effect of heat on photosynthesis, dark respiration and cellular ultrastructure of the arctic-alpine psychrophyte Ranunculus glacialis

W. Larcher, J. Wagner, C. Lütz

Photosynthetica 1996, 34(2):219-232 | DOI: 10.1023/A:1006840623763

Effects of high temperatures on the leaves of Ranunculus glacialis were studied in plants taken from sites located between 2400-2550 m in the Central Alps. Changes in CO2 exchange rates, in vivo chlorophyll fluorescence, and cellular ultrastructure were investigated during and after an experimental heat exposure. The earliest heat stress effect was inactivation of the net photosynthetic rate at 38-39 °C. Between 40-42 °C, disorders appeared in the photosynthetic apparatus and in the tonoplast. Heat shock granules were observed at 42 °C in chloroplasts, and at 44 °C also in mitochondria. In this temperature range, the dark respiration rate was reversibly...

Response of cassava (Manihot esculenta Crantz) to water stress and fertilization

S.M. De Tafur, M.A. El-Sharkawy, L.F. Cadavid

Photosynthetica 1996, 34(2):233-239 | DOI: 10.1023/A:1006892607834

Experiments done in Santander de Quilichao (Cauca, Colombia) on two cassava cultivars indicated that cassava had at least three defence mechanisms against water deficit, enabling it to assimilate and store photosynthates in roots, even during prolonged droughts. These mechanisms include partial stomatal closure, ability of leaves to maintain reasonable net photosynthetic rate for long periods of water stress, reduced leaf area, and exploration of water from deep soil layers. While cassava responded positively to fertilization, no significant statistical differences were found between treatments of stress and non-stress, confirming cassava's ability...

Ord, M.G., Stocken, L.A. (ed.): Foundations of Modern Biochemistry. Vol. 1. Early Adventures in Biochemistry

Z. Šesták

Photosynthetica 1996, 34(2):240 | DOI: 10.1023/A:1006821514194

Cadmium-induced ultrastructural changes in chloroplasts of the leaves and stems parenchyma in Myriophyllum spicatum L.

D.P. Stoyanova, E.S. Tchakalova

Photosynthetica 1996, 34(2):241-248 | DOI: 10.1023/A:1006844724672

After a 5 d cultivation in solutions with different concentrations of cadmium, changes in chloroplasts of the leaf and stem parenchyma from Myriophyllum spicatum L. were observed: swelling and merging of the grana thylakoids in various degrees, coagulation of the stroma as well as the formation of crystal-like structures in it, accompanied by changes in the plastoglobuli and starch. Concentrations of 3.5 and 6.0 g(Cd2+) m-3 caused a vast destruction of the whole plastid apparatus. Chloroplasts in the parenchyma of stems showed a reduction in the inner membrane system, and an increased number of plastoglobuli. A comparative analysis that we carried...

Photosynthesis and water relations of almond tree cultivars grafted on two rootstocks

M.C. Matos, A.A. Matos, A. Mantas, V. Cordeiro, J.B. Vieira Da Silva

Photosynthetica 1996, 34(2):249-256 | DOI: 10.1023/A:1006896708742

Five cultivars of Prunus amygdalus Batsch (Ferragnes, Ferrastar, Marcona, Garrigues, and Non Pareil) grafted on two different rootstocks (Garrigues and GF677), and two cultivars (Ferraduel and Casa Nova) grafted on GF677, were grown for three years under rainfed conditions in an orchard in northeast Portugal. Net photosynthetic rate (PN), leaf conductance for water vapour (gs), leaf water potential (Ψ), instantaneous water use efficiency (WUE), and internal CO2 concentration (Ci) were measured at three periods of the growing season: spring, summer (June or July) and late summer (September) over two years. Ferraduel, Ferrastar, and Marcona presented...

Photosynthetic performance of two coffee species under drought

F.M. Da Matta, M. Maestri, R.S. Barros

Photosynthetica 1996, 34(2):257-264 | DOI: 10.1023/A:1006848825581

Coffea arabica cv. Red Catuaí and C. canephora cv. Kouillou were grown in pots beneath a plastic shelter. When they were 14 months old, irrigation was withheld until the leaf pre-dawn water potential was about -1.5 and -2.7 MPa (designated mild and severe water stress, respectively). Under mild stress, net photosynthetic rate (PN) decreased mainly as a consequence of stomatal limitations in Kouillou, whereas such decreases were dominated by non-stomatal limitations in Catuaí. Under severe drought, further decreases in PN and apparent quantum yield were not associated to any changes in stomatal conductance in either cultivar. Decreases were much more...

Rapid and straightforward estimates of photosynthetic characteristics using a portable gas exchange system

R. Parsons, J.D.B. Weyers, T. Lawson, I.M. Godber

Photosynthetica 1996, 34(2):265-279 | DOI: 10.1023/A:1006800909651

Procedures are described for estimating photosynthetic characteristics using a portable infra-red gas analysis (IRGA) system. Once the effects of stomatal limitation on CO2 assimilation have been established, up to ten parameters of photosynthesis can be estimated for a single leaf within 2 h, including: photosynthetic efficiency and capacity on both photon and CO2 bases; compensation irradiances and CO2 compensation concentrations; and light and dark respiration rates. These measurements can be made in the laboratory, glasshouse or field with relative ease. Methods for obtaining near instantaneous ("snapshot") measurements of leaf photosynthesis are...

Ord, M.G., Stocken, L.A. (ed.): Foundations of Modern Biochemistry. Vol. 2. Quantum Leaps in Biochemistry

Z. Šesták

Photosynthetica 1996, 34(2):280 | DOI: 10.1023/A:1006873531032

The chlorophyll fluorescence quenching and changes of absorbance in pea chloroplasts

I.B. Ganago

Photosynthetica 1996, 34(2):281-291 | DOI: 10.1023/A:1006852926489

Chlorophyll (Chl) fluorescence quenching parameters were measured in dark-adapted pea leaves and chloroplasts with the purpose to find the conditions of high and low non-photochemical quenching, that would be stable during a prolonged irradiation. A PAM fluorometer was used for measuring induction curves in the range of actinic radiation of 3-35 W m-2, with an ordinary value of about 15 W m-2. The effects of various mediators, i.e., ascorbate, methyl viologen (MV), dithiothreitol (DTT) and nigericin, on the quenching process were tested. Simultaneously, the absorbance was measured during a 15-20 min period of irradiation and after the actinic radiation...

Othmer, H.G., Adler, F.R., Lewis, M.A., Dallon, J.C. (ed.): Case Studies in Mathematical Modeling - Ecology, Physiology, and Cell Biology

L. Nátr

Photosynthetica 1996, 34(2):292 | DOI: 10.1023/A:1006825615103

Effects of Cd2+ on the physiological state and photosynthetic activity of young barley plants

A. Vassilev, I. Yordanov, T. Tsonev

Photosynthetica 1996, 34(2):293-302 | DOI: 10.1023/A:1006805010560

Barley plants (Hordeum vulgare L. cv. Obzor) were grown as a water culture in a climatic room. One part of them was subjected to a long-term Cd²⁺ stress - 12 d with 5.4×10^-5 M Cd. The Cd²⁺ stress inhibited formation of the photosynthetic apparatus and its capacity for ¹⁴C photoassimilation, decreased the content of soluble proteins, increased the dark respiration rate and the free amino acids content, disturbed plant water relations, as well as the distribution of ¹⁴C within primary photoproducts of the treated barley plants.

Photosynthesis in rice under a salt stress

B.S. Tiwari, A. Bose, B. Ghosh

Photosynthetica 1996, 34(2):303-306 | DOI: 10.1023/A:1006857027398

In four cultivars of Oryza sativa L., a gradual decrease in the activity of photosystems 1 and 2 as well as in chlorophyll (Chl) fluorescence transients and emission at 688 nm was observed with an increase in NaCl concentration. This decrease was more pronounced in salt-sensitive cultivars as compared to the tolerant ones. A drastic decrease in net photosynthetic rate was found in both cultivar types.

Effect of temperature on photosynthesis of Miscanthus clones collected from different elevations

J. H. Weng, R. G. Ueng

Photosynthetica 1996, 34(2):307-311 | DOI: 10.1023/A:1006809111468

Six to twenty-eight months after transplanting, the net photosynthetic rate (PN) of Miscanthus leaves was measured at leaf temperatures between 18 to 37 °C. PN of clones from high mountain areas was more adaptable to low temperature, while that of clones from low mountain areas was more adaptable to high temperature. The clones from the lowlands were best adapted to both high and low temperatures. These characteristics lasted at least 28 months after transplanting. Thus Miscanthus had differentiated into different ecotypes to adapt to the thermal environments of different elevations. Comparison of the PN values measured in different seasons and durations...

Regulation of chloroplast electron transport and photophosphorylation by externally applied protein factor

V.M. Ivanchenko, M.I. Marshakova, S.V. Vishnyakov, S.N. Shevkova

Photosynthetica 1996, 34(2):313-315 | DOI: 10.1023/A:1006861128307

Pea (Pisum sativum L.) chloroplasts contain water-soluble protein factors. They in vitro activated the rate of Hill reaction and inhibited the photophosphorylation rate.

Photosynthesis of herbaceous plants from nutrient-poor tropical forests

Bee-Lian Ong, Sau-Siong Chan, I.M. Turner

Photosynthetica 1996, 34(2):317-320 | DOI: 10.1023/A:1006813212377

Photosynthetic characteristics, specific leaf mass, chlorophyll and total leaf nitrogen concentrations of four herbaceous plants (Dicranopteris linearis, Hanguana malayana, Pentaphragma ellipticum, Tacca integrifolia) from nutrient-poor tropical forests showed that all these plants were well-adapted to their natural growth environments. No photoinhibition was observed even in the understorey plants.