Turnover of D1 Protein Encoded by psbA Gene in Higher Plants and Cyanobacteria Sustains Photosynthetic Efficiency to Maintain Plant Productivity Under Photoinhibitory Irradiance

M. Singh

Photosynthetica 2000, 38(2):161-169 | DOI: 10.1023/A:1007297227403

The photosynthesis and related plant productivity aspects of plants and cyanobacteria depend upon the functioning of photosystem 2 (PS2), associated with D1 and D2 heterodimer reaction centre core proteins. The D1 protein is encoded by psbA gene, genetically localized on the plastid genome (cpDNA), contains functional cofactors of PS2 in association with D2 protein, and also functions for radiant energy transformation through oxidation of water and reduction of plastoquinone. Surprisingly, D1 protein accounts for even less than 1% of the total thylakoid membrane protein content. In spite of that, its rate of turnover is very much comparable...

Mackenzie, F.T.: Our Changing Planet.An Introduction to Earth System Science and Global Environmental Change. 2^nd Ed.

J. Krekule

Photosynthetica 2000, 38(2):170 | DOI: 10.1023/A:1007275101673

Plant Responses to Drought, Acclimation, and Stress Tolerance

I. Yordanov, V. Velikova, T. Tsonev

Photosynthetica 2000, 38(2):171-186 | DOI: 10.1023/A:1007201411474

At the whole plant level, the effect of stress is usually perceived as a decrease in photosynthesis and growth. That is why this review is focused mainly on the effect of drought on photosynthesis, its injury, and mechanisms of adaptation. The analysed literature shows that plants have evolved a number of adaptive mechanisms that allow the photochemical and biochemical systems to cope with negative changes in environment, including increased water deficit. In addition, the acquisition of tolerance to drought includes both phenotypic and genotypic changes. The approaches were made to identify those metabolic steps that are most sensitive to drought....

Diurnal Oscillation in the Intercellular CO₂ Concentration of Spring Wheat Under the Semiarid Conditions

Xi-ping Deng, Lun Shan, Yong-qing Ma, Shinobu Inanaga

Photosynthetica 2000, 38(2):187-192 | DOI: 10.1023/A:1007253428312

Yields of wheat in semiarid and arid zones are limited by drought, and water condition is very important at each stage of development. Studies carried out at Loess Plateau in the northwestern part of China indicated that yield of spring wheat (Triticum aestivum L.) cv. Dingxi 81-392 was reduced by 41% when subjected to water stress. The effects of two water regimens on net photosynthetic rate (P _N), stomatal conductance (g _s), and intercellular CO₂ concentration (C _i) were investigated at the jointing, booting, anthesis, and grain filling stages. Low soil moisture in comparison...

Partitioning of Photosynthetically Fixed ¹⁴CO₂ Into Oil and Curcumin Accumulation in Curcuma Longa Grown Under Iron Deficiency

Deeksha Dixit, N.K. Srivastava

Photosynthetica 2000, 38(2):193-197 | DOI: 10.1023/A:1007205512382

Changes in leaf growth, photosynthetic efficiency, and incorporation pattern of photosynthetically fixed ¹⁴CO₂ in leaves 1 and 2 from plant apex, in roots, and rhizome induced in Curcuma by growing in a solution culture at Fe concentration of 0 and 5.6 g m^-3 were studied. ¹⁴C was incorporated into primary metabolites (sugars, amino acids, and organic acids) and secondary metabolites (essential oil and curcumin). Fe deficiency resulted in a decrease in leaf area, its fresh and dry mass, chlorophyll (Chl) content, and CO₂ exchange rate at all leaf positions. The rate of ¹⁴CO₂...

Stenesh, J.: Biochemistry

H. Synková

Photosynthetica 2000, 38(2):198 | DOI: 10.1023/A:1007227218511

Physiological Basis of the Difference in Net Photosynthetic Rate of Leaves between Two Maize Strains

Hua Jiang, Da-Quan Xu

Photosynthetica 2000, 38(2):199-204 | DOI: 10.1023/A:1007257529221

Significant differences in net photosynthetic rate (P _N) of leaves between two maize (Zea mays L.) strains (Shuang 105 and 40×44) grown in the field were observed. At several growth stages, P _N of 40×44 was higher than that of Shuang 105 (from 10.3 to 32.5 %). Moreover, the strain 40×44 had a higher plant height, larger leaf area, lower chlorophyll content, and higher photochemical efficiency of photosystem 2 (PS2) (F_v/F_m and ΔF/F_m') than strain Shuang 105. Shuang 105, which showed lower P _N, had lower stomatal conductances (g _s) but...

Responses of the Antioxidant Systems and Xanthophyll Cycle in Phaseolus vulgaris to the Combined Stress of High Irradiance and High Temperature

Liang Ye, Hui-yuan Gao, Qi Zou

Photosynthetica 2000, 38(2):205-210 | DOI: 10.1023/A:1007209613291

Changes in the activities of enzymes involved in scavenging active oxygen species were followed after exposing bean seedling leaves (Phaseolus vulgaris L.) to various cross stresses of irradiance and temperature. The activities of superoxide dismutase (SOD, EC 1.15.1.1) and ascorbate peroxidase (AsAPOD, EC 1.11.1.11) increased to different extent with prolonged irradiation of the leaves, and were stimulated by high temperature (HT). The activity of catalase (CAT, 1.11.1.6) decreased when exposed to strong irradiance (HI), and the decrease was further exacerbated when HI was combined with HT. CAT activity was more sensitive to HT than...

Synergistic Effect of AlCl₃ and Kinetin on Chlorophyll and Protein Contents and Photochemical Activities in Detached Wheat Primary Leaves during Dark Incubation

D. Subhan, S.D.S. Murthy

Photosynthetica 2000, 38(2):211-214 | DOI: 10.1023/A:1007261614200

Al³⁺ in combination with kinetin showed more protection against degradation of chlorophyll (Chl) and protein than Al³⁺ or kinetin alone during dark-induced senescence in wheat primary leaf segments. MV-dependent whole chain electron transport, photosystem (PS) 2 mediated oxygen evolution, and PS1 activities were also delayed to a greater extent. Absorbed excitation energy distribution was more in favour of PS1 in Al³⁺ plus kinetin-treated leaf thylakoids at 72 h.

Activities of Phosphoenolpyruvate Carboxylase and Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase in Leaves and Fruit Pericarp Tissue of Different Coffee (Coffea sp.) Genotypes

Y. Lopez, N. Riaño, P. Mosquera, A. Cadavid, J. Arcila

Photosynthetica 2000, 38(2):215-220 | DOI: 10.1023/A:1007265715108

In order to study photosynthetic characteristics, phosphoenolpyruvate carboxylase (PEPC) and ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) activities as well as soluble protein and chlorophyll contents were determined in leaf and fruit pericarp samples from diverse coffee genotypes (Coffea arabica cv. Colombia, Caturra, Caturra Erecta, San Pacho, Tipica, C. stenophylla, C. eugenioides, C. congensis, C. canephora, C. canephora cv. Arabusta, C. arabica cv. Caturra×C. canephora and Hibrido de Timor. We found a slightly higher PEPC activity in fruit pericarp than in leaves, while RuBPCO activity was much lower in...

Increase in Resistance to Low Temperature Photoinhibition Following Ascorbate Feeding is Attributable to an Enhanced Xanthophyll Cycle Activity in Rice (Oryza sativa L.) Leaves

C. C. Xu, R. C. Lin, L. B. Li, T. Y. Kuang

Photosynthetica 2000, 38(2):221-226 | DOI: 10.1023/A:1007269931946

The mechanistic basis for protection of exogenous ascorbate against photoinhibition at low temperature was examined in leaves of rice (Oryza sativa L.). Exposure of intact leaves to chilling temperature resulted in a drastic decrease in the speed of development of non-photochemical fluorescence quenching (NPQ). This was related to the low temperature-imposed restriction on the formation of the fast relaxing component of NPQ (q_f). Feeding with 20 mM ascorbate markedly increased the rate of q_f development at chilling temperature due primarily to the enhanced rate of zeaxanthin (Z) formation. On the other hand, ascorbate feeding...

Chain Correlation between Variables of Gas Exchange and Yield Potential in Different Winter Wheat Cultivars

G.M. Jiang, N.B. Hao, K.Z. Bai, Q.D. Zhang, J.Z. Sun, R.J. Guo, Q.Y. Ge, T.Y. Kuang

Photosynthetica 2000, 38(2):227-232 | DOI: 10.1023/A:1007222016017

Variables of gas exchange of flag leaves and grain yield potentials of five representative winter wheat (Triticum aestivum L.) cultivars varied greatly across different development stages under the same management and irrigation. The cultivars with high yield potential had higher net photosynthetic rate (P _N), PPFD (photosynthetic photon flux density) saturated photosynthetic rate (P _sat), stomatal conductance (g _s), and maximum apparent quantum yield of CO₂ fixation (Φ_m,app) than those with low grain yield, but their dark respiration rate (R _D)...

Morphological and Physiological Differences in Synechococcus elongatus during Continuous Cultivation at High Iron, Low Iron, and Iron Deficient Medium

J. Benešová, K. Ničková, N. Ferimazova, D. Štys

Photosynthetica 2000, 38(2):233-241 | DOI: 10.1023/A:1007274000087

Thermophilic unicellular cyanobacterium Synechococcus elongatus Näg. var. thermalis Geitl. strain Kovrov 1972/8 was cultivated in continuous flow reactor to simulate conditions occurring in nature in regions with low iron concentration. Two degrees of iron deprivation were established: (a) low iron (LI) conditions (9.0 µM Fe) when cells still maintained maximal growth rate but already exhibited changes in photosynthetic apparatus, and (b) iron deficient (ID) conditions (0.9 µM Fe) when cell growth rate decreased and extensive morphological and functional changes were observed. A decrease in the cellular content...

Kohlmaier, G.H., Weber, M., Houghton, R.A. (ed.): Carbon Dioxide Mitigation in Forestry and Wood Industry

J. Čatský

Photosynthetica 2000, 38(2):242 | DOI: 10.1023/A:1007223117602

Effect of Salicylic Acid on Leaf Anatomy and Chloroplast Ultrastructure of Barley Plants

A.N. Uzunova, L.P. Popova

Photosynthetica 2000, 38(2):243-250 | DOI: 10.1023/A:1007226116925

Light and electron microscopy were used to relate histological and ultrastructural differences of barley leaves treated with different concentrations of salicylic acid (SA, 100 µM-1 mM). Light microscopy revealed that the thickness of all leaf tissue components decreased in SA-treated plants. The effect was most pronounced on the width of the adaxial epidermis and on the size of the bulliform cells. The chloroplast ultrastructure was also affected by SA treatment. Swelling of grana thylakoids in various degrees, coagulation of the stroma, and increase in chloroplast volume were observed. 1 mM SA caused a vast destruction of the whole plastid structure.

Properties of Photosynthetic Bacteria in Anisotropic Rigid Matrix and in Suspension

A. Planner, M. Hara, Z. Stachowiak, J. Miyake

Photosynthetica 2000, 38(2):251-258 | DOI: 10.1023/A:1007278100996

The photosynthetic bacteria (Rhodospirillum rubrum, Synechococcus and Anabaena variabilis) as well as their fragments embedded in isotropic and anisotropic polymer film were investigated. The orientation of photosynthetic pigments inside these organisms was compared, on the basis of the polarised absorption and fluorescence spectra, with the macroscopic orientation of investigated objects seen under microscope. The anisotropy of fluorescence was much higher than anisotropy of absorption. It showed strong influence of the photoselection by polarised radiation on the various bacterial chromophores exhibiting different orientations in the...

Polarized Photoacoustic Spectra of the Cyanobacterium Synechococcus Oriented in Polymer Film

A. Planner, M. Hara, J. Miyake, A. Waszkowiak, K. Klaczyńska, D. Frąckowiak

Photosynthetica 2000, 38(2):259-266 | DOI: 10.1023/A:1007230217834

Photoacoustic spectra (PAS) were obtained for the cyanobacterium Synechococcus (Anacystis nidulans) cells embedded in isotropic and stretched polyvinyl alcohol films. The polarized radiation with the electric vector changing in 30° intervals with respect to given direction in a sample plane was used. Two cyanobacterium strains, one with very low biliprotein content, second with normal amount of biliproteins were investigated. The polarized absorption and fluorescence spectra were also measured. Conclusions were drawn about the thermal deactivation occurring in differently oriented pools of chromophores and about mutual orientation of...

Differential Photosynthetic Acclimation Pattern to Limiting Growth-Irradiance in Two Types of C₄ Plants

M.V. Sailaja, V.S. Rama Das

Photosynthetica 2000, 38(2):267-273 | DOI: 10.1023/A:1007246314876

Photosynthetic acclimation to reduced growth irradiances (650 and 200 µmol m^-2 s^-1) in Eleusine coracana (L.) Garten, a nicotinamide adenine dinucleotide-malic enzyme (NAD-ME) C₄ species and Gomphrena globosa L., a nicotinamide adenine dinucleotide phosphate-malic enzyme (NADP-ME) C₄ species were investigated. E. coracana plants acclimated in 4 and 8 d to 650 and 200 µmol m^-2 s^-1, respectively, whereas G. globosa plants took 8 and 10 d, respectively, to acclimate to the same irradiances. The acclimation to reduced irradiance was achieved in both...

Alvarez-Cobelas, M., Reynolds, C.S., Sanchez-Castillo, P., Kristiansen, J. (ed.): Phytoplankton and Trophic Gradients

V. Zachleder

Photosynthetica 2000, 38(2):274 | DOI: 10.1023/A:1007271000764

Partitioning of ¹⁴C-Photosynthate of Leaves in Roots, Rhizome, and in Essential Oil and Curcumin in Turmeric (Curcuma longa L.)

Deeksha Dixit, N.K. Srivastava

Photosynthetica 2000, 38(2):275-280 | DOI: 10.1023/A:1007262831715

Incorporation of photosynthetically fixed ¹⁴C was studied at different time intervals of 12, 24, and 36 h in various plant parts-leaf 1 to 4 from apex, roots, and rhizome-into primary metabolites-sugars, amino acids, and organic acids, and secondary metabolites-essential oil and curcumin-in turmeric. The youngest leaves were most active in fixing ¹⁴C at 24 h. Fixation capacity into primary metabolites decreased with leaf position and time. The primary metabolite levels in leaves were maximal in sugars and organic acids and lowest in amino acids. Roots as well as rhizome received maximum photoassimilate from leaves at 24 h; this...

Chlorophyll a Fluorescence Emission, Xanthophyll Cycle Activity, and Net Photosynthetic Rate Responses to Ozone in Some Foliose and Fruticose Lichen Species

A. Calatayud, P.J. Temple, E. Barreno

Photosynthetica 2000, 38(2):281-286 | DOI: 10.1023/A:1007214915785

The lichens Parmelia quercina, Parmelia sulcata, Evernia prunastri, Hypogymnia physodes, and Anaptychia ciliaris were exposed to ozone (O₃) in controlled environment cuvettes designed to maintain the lichens at optimal physiological activity during exposure. Measurements of gas exchange, modulated chlorophyll (Chl) fluorescence, and pigment analysis were conducted before and after exposure to 300 mm³ (O₃) m^-3, 4 h per d for 14 d. No changes in the efficiency of photosystem 2 (PS2) photochemistry, the reduction state of Q_A, or the electron flow through PS2, measured...

Effect of Salinity on Photosynthesis and Biochemical Characteristics in Mulberry Genotypes

P. Agastian, S.J. Kingsley, M. Vivekanandan

Photosynthetica 2000, 38(2):287-290 | DOI: 10.1023/A:1007266932623

Mulberry genotypes were subjected to salinity (0-12 mS cm^-1) in pot culture experiment. Chlorophyll and total carotenoid contents were reduced considerably by salinity. At low salinity, photosynthetic CO₂ uptake increased over the control, but it decreased at higher salinity. Contents of soluble proteins, free amino acids, soluble sugars, sucrose, starch, and phenols increased at salinity of 1-2 mS cm^-1 and decreased at higher salinity (8-12 mS cm^-1). Glycine betaine accumulated more than proline, the maximum accumulation of both was at salinity of 2-4 mS cm^-1. Among the genotypes studied, BC2-59...

Bibliography of Reviews and Methods of Photosynthesis - 83

Z. Šesták, J. Čatský

Photosynthetica 2000, 38(2):291-320 | DOI: 10.1023/A:1007219016694