Thylakoid Membrane Protein Kinase Activity as a Signal Transduction Pathway in Chloroplasts

A.N. Misra, A.K. Biswal

Photosynthetica 2000, 38(3):323-332 | DOI: 10.1023/A:1010956516328

In plants external stimuli are perceived through a cascade of signals and signal transduction pathways. Protein phosphorylation and de-phosphorylation is one of the most important transduction paths for the perception of signals in plants. The highest concentrations of plant phospho-proteins are located in chloroplasts. This facilitates the protection of thylakoid membranes from stress-induced damage and augments adaptive strategies in plants. In this review, the protein kinases associated with phosphorylation of thylakoid membrane protein, and the adaptive changes in thylakoid membrane architecture and developmental cues are given. The presence of...

Influence of Water on the Primary Photosynthetic Activity of Rhodospirillum Rubrum in Reverse Micelles

A. Srivastava, A. Darszon, R.J. Strasser

Photosynthetica 2000, 38(3):333-341 | DOI: 10.1023/A:1010905100398

The effect of water on the primary photosynthetic activity of purple bacterium Rhodospirillum rubrum was studied in Hexadecane-Tween-Spane (HTS)- and phospholipid (PLC)-reverse micelles. Reverse micelles offer the possibility of modulating the amount of water to which enzymes and multienzymatic complexes are exposed. Fast bacteriochlorophyll (BChl) fluorescence induction kinetics and reaction centre absorption changes at 820 nm were used as an assay for the functional transfer of bacterial cells into HTS-reverse micelles and bacterial photosynthetic complexes (BPC) into PLC-reverse micelles. Both the bacterial cells and BPC showed an increase...

Moore, P., Cobby, J.: Introductory Statistics for Environmentalists

R. Krejčí

Photosynthetica 2000, 38(3):342 | DOI: 10.1023/A:1010966814028

The Salinity Tolerance of Freshwater Cyanobacterium Synechococcus sp. PCC 7942 is Determined by Its Ability for Osmotic Adjustment and Presence of Osmolyte Sucrose

N.P. Ladas, G.C. Papageorgiou

Photosynthetica 2000, 38(3):343-348 | DOI: 10.1023/A:1010957117237

We investigated the factors that impose an upper limit of salinity tolerance to the unicellular freshwater cyanobacterium Synechococcus sp. PCC 7942. Above approx. 0.4 M NaCl, Synechococcus cells cease to proliferate, after having accumulated 0.3 M sucrose. Cells that pre-accumulated sucrose could tolerate up to 0.5 M NaCl, but not 0.6 M NaCl. After exposure to 0.5 M NaCl or higher, the cells were irreversibly modified becoming unable for osmotic volume adjustments.

How Wind Affects the Photosynthetic Performance of Trees: Quantified with Chlorophyll a Fluorescence and Open-Top Chambers

A.J. Clark, W. Landolt, J.B. Bucher, R.J. Strasser

Photosynthetica 2000, 38(3):349-360 | DOI: 10.1023/A:1010909201307

Meteorological parameters inside and outside an open-top chamber (OTC) fumigation facility were recorded and the primary photosynthetic response of four tree species measured with chlorophyll (Chl) a fluorescence emission. Parameters extracted from the Chl a fluorescence transient were used to calculate photosynthetic activity of the leaves using a performance index. Measurements were made during the night throughout a single growing season. The seasonal primary photosynthetic performance in all species was significantly altered by growth in the OTCs, and the degree of response was dependent upon the species. Wind was an important effectual...

Effects of Water Stress and High-Temperature Stress on the Structure and Activity of Photosynthetic Apparatus of Zea Mays and Helianthus Annuus

I. Dekov, T. Tsonev, I. Yordanov

Photosynthetica 2000, 38(3):361-366 | DOI: 10.1023/A:1010961218145

Effects of high-temperature stress (HTS) and PEG-induced water stress (WS), applied separately or in combination, on the functional activity and ultrastructure of the photosynthetic apparatus (PSA) of maize (Zea mays L.) and sunflower (Helianthus annuus L.) plants were investigated. In maize plant tissues WS provoked the decrease in RWC by 10.9 %, HTS by 7.0 %, and after simultaneous application of the both treatments the decrease was 32.7 % in comparison with control plants. Similar but more expressed changes were observed in sunflower plants. Sunflower was more sensitive to these stresses. Net photosynthetic rate decreased significantly...

Altitudinal Changes in Photosynthetic Pathways of Floristic Elements in Southern Sinai, Egypt

O.H. Sayed, M.K. Mohamed

Photosynthetica 2000, 38(3):367-372 | DOI: 10.1023/A:1010913302216

High altitude profoundly influenced plant diversity and distribution on mountains of southern Sinai (Egypt). Plants exhibiting the C₃-mode of photosynthesis were widely distributed along the altitudinal transect. Plants exhibiting the C₄-mode were restricted below an altitude of about 1400 m above sea level. The transition from C₃-dominated areas to C₄-dominated areas occurred between 1200 and 1400 m a.s.l.

Similar Susceptibility to Excess Irradiance in Sun and Shade Acclimated Saplings of Norway Spruce [Picea Abies (L.) Karst.] and Stone Pine (Pinus Cembra L.)

R. Gamper, S. Mayr, H. Bauer

Photosynthetica 2000, 38(3):373-378 | DOI: 10.1023/A:1010965319054

We compared the responses of sun and shade acclimated saplings of Picea abies and Pinus cembra to excess photosynthetic photon flux density (PPFD) equivalently exceeding the level for saturating net photosynthetic rate (P_N). Exposure for 2 h up to 2000 µmol(photon) m^-2 s^-1 did not affect radiant energy saturated P_N. Photoinhibition of photosynthesis was indicated by a small (10 %) reduction of the potential efficiency of photosystem 2 as derived from measurements of chlorophyll fluorescence (F_V/F_M). However, the extent of F_V/F_M...

Evaluating the Superoxide Dismutase Activity and Chlorophyll Fluorescence in Picea Abies Leaves Growing at Different Altitudes

Z. Miszalski, E. Niewiadomska, E. Kępa, P. Skawiński

Photosynthetica 2000, 38(3):379-384 | DOI: 10.1023/A:1010917403124

Superoxide dismutase (SOD) activity and parameters of chlorophyll fluorescence, the ratio of maximal to variable fluorescence (F_v/F_m), maximal fluorescence (F_m), and minimal fluorescence (F₀) were determined on Picea abies growing at different altitudes. The decreases of F_v/F_m and F_m, in comparison to samples from the lower stands (control), were found on trees from the highest stands. The decrease of fluorescence parameters was reversible, at least partly, after keeping branches for some days in the laboratory. F_v/F_m measured in spring when trees...

Changes in Properties of Phosphoenolpyruvate Carboxylase with Induction of Crassulacean Acid Metabolism (CAM) in the C₄ Plant Portulaca Oleracea

A.M.A. Mazen

Photosynthetica 2000, 38(3):385-391 | DOI: 10.1023/A:1010969419962

Aiming at understanding the odd case of CAM expression by a C₄ plant, some properties of phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31, orthophosphate: oxaloacetate carboxylyase, phosphorylating) were comparatively studied in leaves of CAM-expressing and non-expressing Portulaca oleracea L. plants. CAM expression was induced by growing plants under an 8-h photoperiod and under water-stress. CAM induction in leaves of these plants (designated as CAM) is indicated by the nocturnal acidification and by the clear diurnal oscillation pattern and amplitude of acidity, malic acid, and PEPC activity characteristic of CAM plants....

Clark, C.W., Mangel, M.: Dynamic State Variable Models in Ecology: Methods and Applications

L. Nátr

Photosynthetica 2000, 38(3):392 | DOI: 10.1023/A:1010910629049

Changes in Photosynthetic Performance of Ceratonia Siliqua in Summer

J.C. Ramalho, J.A. Lauriano, M.A. Nunes

Photosynthetica 2000, 38(3):393-396 | DOI: 10.1023/A:1010921504033

In carob tree (Ceratonia siliqua) radiant energy saturated net photosynthetic rate (P_N) during summer was about 10 % of the spring values. This was accompanied by a reduction in stomatal conductance (g_s), which only partially explains the strong reduction in P_N. Photosynthetic capacity (P_max) and quantum yield (Φ), both measured under saturating CO₂, had the maximum in spring (about 34 μmol m^-2 s^-1 and 0.08 mol mol^-1, respectively) and both decreased in late summer to about 55 % of their spring values. Despite strong decreases...

Effect of Fruiting on Leaf Gas Exchange in Olive (Olea Europaea L.)

P. Proietti

Photosynthetica 2000, 38(3):397-402 | DOI: 10.1023/A:1010973520871

The effect on traits of photosynthesis and water relations of assimilate demand was studied in olive tree that has strong alternate bearing. The diurnal and seasonal leaf gas exchanges, area dry mass, and saccharide and chlorophyll (Chl) contents were measured by comparing shoots with fruit of "on-trees" (heavy fruit load) with shoots without fruit on both "on-trees" and "off-trees" (light fruit load). In spite of large seasonal and diurnal differences, leaf net photosynthetic rate (P_N), stomatal conductance (g_s), sub-stomatal CO₂ concentration (C₁), transpiration rate (E), and...

Hormonal Regulation of Photosynthetic Enzymes in Cotton under Water Stress

D.M. Pandey, C.L. Goswami, B. Kumar, Sudha Jain

Photosynthetica 2000, 38(3):403-407 | DOI: 10.1023/A:1010925604941

Activities of ribulose bisphosphate carboxylase/oxygenase (RuBPCO), phosphoenolpyruvate carboxylase (PEPC), and carbonic anhydrase (CA) were determined in leaves of cotton (Gossypium hirsutum L. cv. H-777) subjected to 8-d waterlogging (WL) at the vegetative stage, or to drought (D) at the reproductive stage, or to interaction of both stresses. The soil moisture of control plants was kept at field capacity. One day prior to stress various growth hormones (5 μM) were sprayed up to runoff. WL reduced RuBPCO and CA activities, while PEPC activity increased. Upon D, RuBPCO and PEPC activities were reduced while CA activity was increased. Imposition...

Deaton, M.L., Winebrake, J.J.: Dynamic Modeling of Environmental Systems

L. Nátr

Photosynthetica 2000, 38(3):408 | DOI: 10.1023/A:1010962713119

Effects of Ozone Fumigation on Photosynthesis and Membrane Permeability in Leaves of Spring Barley, Meadow Fescue, and Winter Rape

A. Plażek, M. Rapacz, A. Skoczowski

Photosynthetica 2000, 38(3):409-413 | DOI: 10.1023/A:1010977605850

Seedlings of spring barley, meadow fescue, and winter rape were fumigated with 180 μg kg^-1 of ozone for 12 d, and effect of O₃ on photosynthesis and cell membrane permeability of fumigated plants was determined. Electrolyte leakage and chlorophyll fluorescence were measured after 6, 9, and 12 d of fumigation, while net photosynthetic rate (P_N) and stomatal conductance (g_s) were measured 9 d after the start of ozone exposure. O₃ treatment did not change membrane permeability in fescue and barley leaves, while in rape a significant decrease in ion leakage was noted within the whole...

Maillard, P., Bonhomme, R. (ed.): Fonctionnement des Peuplements Végétaux Sous Contraintes Environmentales

J. Čatský

Photosynthetica 2000, 38(3):414 | DOI: 10.1023/A:1010914829957

Phosphoenolpyruvate Carboxylase Purified from Leaves of C₃, C₄, and C₃-C₄ intermediate species of Alternanthera: Properties at Limiting and Saturating Bicarbonate

Bhaskarrao Chinthapalli, Chitra Raghavan, O. Bläsing, P. Westhoff, A.S. Raghavendra

Photosynthetica 2000, 38(3):415-419 | DOI: 10.1023/A:1010981807667

Phosphoenolpyruvate carboxylase (PEPC) was purified from leaves of four species of Alternanthera differing in their photosynthetic carbon metabolism: Alternanthera sessilis (C₃), A. pungens (C₄), A. ficoides and A. tenella (C₃-C₄ intermediates or C₃-C₄). The activity and properties of PEPC were examined at limiting (0.05 mM) or saturating (10 mM) bicarbonate concentrations. The V_max as well as K_m values (for Mg²⁺ or PEP) of PEPC from A. ficoides and A. tenella (C₃-C₄ intermediates)...

Low Night Temperature-Induced Changes in Photosynthesis and Rubber Accumulation in Guayule (Parthenium Argentatum Gray)

D. Sundar, A. Ramachandra Reddy

Photosynthetica 2000, 38(3):421-427 | DOI: 10.1023/A:1010990024506

Three-year-old plants of Parthenium argentatum Gray cv. 11591 grown under natural photoperiod were exposed for 60 d to low night temperature (LNT) of 15 °C (daily from 18:00 to 06:00). Effects of the treatment on net photosynthetic rates (P_N), rubber accumulation, and associated biochemical traits were examined. LNT initially reduced P_N with a parallel decline in the activities of ribulose-1,5-bisphosphate carboxylase, fructose bisphosphatase, and sucrose phosphate synthase for 20-30 d. Later, LNT enhanced P_N and the activities of photosynthetic enzymes. Associated with high P_N...

Gas Exchange of Spring Barley and Wheat Grown under Mild Water Shortage

T. Łoboda

Photosynthetica 2000, 38(3):429-432 | DOI: 10.1023/A:1010942108576

During mild water stress (decrease of full water capacity from 60 to 35 %) net photosynthetic rate (P_N) of four spring barley and wheat genotypes was about twice lower than that for unstressed plants and was mainly limited by non-stomatal factors. Availability of CO₂ from intercellular spaces did not change significantly when stomatal conductance (g_s) decreased from 0.25-0.35 to 0.15-0.20 mol(H₂O) m^-2 s^-1. There may be two main processes leading to similar intercellular CO₂ concentration (c_i) in stressed and unstressed seedlings despite of twice...

The Synapse-Like Interaction between Chloroplast, dictyosome, and Other Cell Compartments during Increased Ethylene Production in Leaves of Rye (Secale cereale L.)

T. Selga, M. Selga

Photosynthetica 2000, 38(3):433-441 | DOI: 10.1023/A:1010994125414

Rye (Secale cereale L.) plants were treated with an ethylene releaser ethephon (2-chloroethylphosphonic acid) in concentration of 4×10^-2 M. We studied electron microscopically, if and how chloroplasts interact with well-documented sites of ethylene production/binding, i.e., with endoplasmic reticulum, dictyosomes, mitochondria, plasma membrane, and tonoplast. During the sharp increase of ethylene synthesis in mesophyll cells of rye leaves, the direct local continguity of chloroplast envelope or envelope protrusions with the above mentioned cell compartments was typical. Moreover, a large number and diversity of versatile chloroplast-dictyosome...

Effects of Drought Stress Induced by Polyethylene Glycol on Pigment Content and Photosynthetic Gas Exchange of Pistacia Khinjuk and P. Mutica

A. Ranjbarfordoei, R. Samson, P. Van Damme, R. Lemeur

Photosynthetica 2000, 38(3):443-447 | DOI: 10.1023/A:1010946209484

The effects of drought stress induced by polyethylene glycol, PEG (molecular mass 6000) on some ecophysiological characteristics of two wild pistachio species, Mastic and Khinjuk (P. mutica and P. khinjuk) selected as root stocks for production of edible pistachio trees (P. vera) in Iran and Turkey, were studied. Net photosynthetic rate (P_N), stomatal conductance (g_s), chlorophyll (Chl) fluorescence parameters, leaf water potential (Ψ₁), leaf osmotic potential (Ψ_π), leaf osmotic adjustment (ΔΨ_π), and Chl a and b were measured....

Influence of Manganese Toxicity on Photosynthesis in Ricebean (Vigna Umbellata) Seedlings

Desiraju Subrahmanyam, V.S. Rathore

Photosynthetica 2000, 38(3):449-453 | DOI: 10.1023/A:1010998226323

Influence of manganese (Mn) toxicity on photosynthesis in ricebean (Vigna umbellata) was studied by the measurement of gas exchange characteristics and chlorophyll fluorescence parameters. The net photosynthetic rate (P_N), transpiration rate (E), and stomatal conductance (g_s) were reduced with increasing Mn concentration in nutrient solution. The reduction in g_s and E was more pronounced at 6 d of Mn treatment. However, P_N declined at 2 d of Mn treatment implying that the reduction in photosynthesis was not due to the direct effect of Mn on stomatal regulation....

Organisation of Photosynthetic Apparatus of Triticale in Relation to Productivity

S.N. Kabanova, L.F. Kabashnikova, E.V. Serduchenko, L.N. Kalituho, M.T. Chaïka

Photosynthetica 2000, 38(3):455-463 | DOI: 10.1023/A:1010950310393

Chlorophyll (Chl) content, photochemical activity of chloroplasts as well as photosynthetic and crop productivity were studied in different winter hexaploid Triticale (xTriticosecale Witt.) lines and their F₁ hybrids. Heterosis enhanced Chl content, photosynthetic potential, photosynthetic productivity, and grain yield only in several F₁ hybrids of Triticale. Indication in some genotypes of close correlations among morphological structure, Chl content, photochemical activity of chloroplasts, photosynthetic potential, and plant productivity may be used in breeding practice of Triticale.

Tolerance to Water Stress in Tomato Cultivars

N.K. Srinivasa Rao, R.M. Bhatt, A.T. Sadashiva

Photosynthetica 2000, 38(3):465-467 | DOI: 10.1023/A:1010902427231

The effects of plant water stress imposed at vegetative, flowering, and fruiting stages of four cultivars of tomato (Lycopersicon esculentum Mill.) on net photosynthetic rate (P_N), stomatal conductance (g_s), transpiration rate (E), osmotic adjustment, and crop water stress index (CWSI) were investigated. Osmotic adjustment was the highest in cv. Arka Meghali, followed by cv. RFS-1. CWSI was lowest in cv. Arka Meghali and highest in cv. Pusa Ruby. Significant reduction in g_s, E, and P_N was observed in all the cultivars. The maximum reduction in E was...

Photosynthetic Rate, Growth, and Yield of Mustard Plants Sprayed with 28-Homobrassinolide

S. Hayat, A. Ahmad, M. Mobin, A. Hussain, Q. Fariduddin

Photosynthetica 2000, 38(3):469-471 | DOI: 10.1023/A:1010954411302

Thirty-day-old plants of mustard (Brassica juncea L.) were sprayed with 10^-10, 10^-8, or 10^-6 M aqueous solution of 28-homobrassinolide (HBR). The HBR-treated plants were healthier than those treated with water and yielded more. Maximum increase over control was found in 60-d-old, 10^-8 M-HBR-treated plants in fresh and dry mass per plant, carbonic anhydrase (CA, E.C. 4.2.1.1) activity, and net photosynthetic rate (P_N), at harvest in number of pods per plant and seed yield per plant (the respective values were 25, 30, 34, 69, 24, and 29 %). A further increase in the concentration of...

Translocation of ¹⁴C-(Labelled) Photosynthates in Groundnut (Arachis Hypogaea L.) Infected with Macrophomina Phaseoli (Maub) Ashby

I.C. Okwulehie

Photosynthetica 2000, 38(3):473-476 | DOI: 10.1023/A:1010906528140

At various intervals after inoculation of the roots of groundnut plants with the fungus Macrophomina phaseoli, ¹⁴CO₂ was administered to branch 2 (from the base) of the plants in the light. The effects of the disease on the translocation of ¹⁴C-photosynthates out of the source branch to the rest of the plant were studied 24 h after labelling. As the plant aged and the disease symptom development became more evident, an increasing percentage of the fixed ¹⁴C-photosynthates was exported from branch 2 of the inoculated plants (IP) compared to the non-inoculated plants (NIP). The apex, main stem, and branch...

Differential Responses of Iron, Magnesium, and Zinc Deficiency on Pigment Composition, Nutrient Content, and Photosynthetic Activity in Tropical Fruit Crops

K. Balakrishnan, C. Rajendran, G. Kulandaivelu

Photosynthetica 2000, 38(3):477-479 | DOI: 10.1023/A:1010958512210

Fe, Mn, and Zn affected the chlorophyll (Chl) content whereas Fe deficiency caused larger reduction of total chlorophyll content than Mg and Zn deficiencies. Mg deficient mango had a higher Chl a/b ratio than the respective healthy plants. The foliar contents of Fe, Zn, and Mg in the deficient leaves were lower than the critical level. Nutrient deficiency significantly affected the F_v/F_m ratios as observed from the Chl fluorescence induction curves. Fe deficiency resulted in larger reduction of variable fluorescence than Mg and Zn deficiency.

Helmut Metzner; 15 September 1925 - 20 September 1999

Photosynthetica 2000, 38(3):321 | DOI: 10.1023/A:1017317132258