The Light-Dependent and Light-Independent Reduction of Protochlorophyllide a to Chlorophyllide a

B. Schoefs

Photosynthetica 1998, 36(4):481-496 | DOI: 10.1023/A:1007002101856

Two different pathways for protochlorophyllide a (Pchlide) reduction in photosynthetic organisms have been proved: one is strictly light-dependent whereas the second is light-independent. Both pathways occur in all photosynthetic cells except in angiosperms which form chlorophyll only through the light-dependent pathway. Most cells belonging to Eubacteria (i.e., the anoxygenic photosynthetic bacteria) synthesize bacteriochlorophyll through the light-independent pathway. This review deals with the physiological, biochemical, and molecular biological features of molecules involved in both pathways of Pchlide reduction.

The Development of Chloroplast Ultrastructure and Hill Reaction Activity During Leaf Ontogeny in Different Maize (Zea Mays L.) Genotypes

J. Kutík, M. Kočova, D. Holá, M. Körnerová

Photosynthetica 1998, 36(4):497-507 | DOI: 10.1023/A:1007031818695

Changes in Hill reaction activity (HRA) and ultrastructure of mesophyll cell (MC) chloroplasts were studied during the ontogeny of third leaf of maize plants using polarographic oxygen evolution measurement, transmission electron microscopy, and stereology. The chloroplast ultrastructure was compared in young (actively growing), mature, and senescing leaves of two different inbreds and their reciprocal F1 hybrids. Statistically significant differences in both HRA and MC chloroplast ultrastructure were observed between different stages of leaf ontogeny. Growth of plastoglobuli was the most striking characteristic of chloroplast maturation and senescence....

Plant Analysis: An Interpretation Manual

L. Nátr

Photosynthetica 1998, 36(4):508 | DOI: 10.1023/A:1007029112760

Influence of Etherel and Gibberellic Acid on Carbon Metabolism, Growth, and Essential Oil Accumulation in Spearmint (Mentha Spicata)

Preety Singh, N.K. Srivastava, A. Mishra, S. Sharma

Photosynthetica 1998, 36(4):509-517 | DOI: 10.1023/A:1007083802765

Changes in growth parameters and ¹⁴CO₂ and [U-¹⁴C]-sucrose incorporation into the primary metabolic pools and essential oil were investigated in leaves and stems of M. spicata treated with etherel and gibberellic acid (GA). Compared to the control, GA and etherel treatments induced significant phenotypic changes and a decrease in chlorophyll content, CO₂ exchange rate, and stomatal conductance. Treatment with etherel led to increased total incorporation of ¹⁴CO₂ into the leaves wheras total incorporation from ¹⁴C sucrose was decreased. When ¹⁴CO₂...

A Molecular Approach to Primary Metabolism in Higher Plants

Z. Šesták

Photosynthetica 1998, 36(4):518 | DOI: 10.1023/A:1007072927781

Sucrose Metabolism at Three Leaf Development Stages in Bean Plants

M. Castrillo

Photosynthetica 1998, 36(4):519-524 | DOI: 10.1023/A:1007035919603

Sucrose metabolism was studied at three leaf development stages in two Phaseolus vulgaris L. cultivars, Tacarigua and Montalban. The changes of enzyme activities involved in sucrose metabolism at the leaf development stages were: (1) Sink (9-11 % full leaf expansion, FLE): low total sucrose phosphate synthase (SPS) activity, and higher acid invertase (AI) activity accompanied by low sucrose synthase (SuSy) synthetic and sucrolytic activities. (2) Sink to source transition (40-47 % FLE): increase in total SPS and SuSy activities, decrease in AI activity. (3) Source (96-97 % FLE): high total SPS activity, increased SuSy activities,...

Light Absorption and Competition in Mixed Communities of Hordeum Leporinum-Euphorbia Scordifolia

F.G.M.A. Khadr

Photosynthetica 1998, 36(4):525-531 | DOI: 10.1023/A:1007087903674

The effect of Euphorbia scordifolia and Hordeum leporinum competition on leaf area development, radiant energy absorption, and dry matter production was evaluated in a field experiment. Profile measurements (0-0.3, 0.3-0.6, 0.6-0.9, and >0.9 m above ground) of absorbed photosynthetically active radiation (APAR) and leaf area index (LAI) by species were taken at four densities of E. scordifolia (0, 1, 4, and 12 plants per m²). APAR calculated for H. leporinum in mixed communities was 79, 77, and 49 % of the APAR in H. leporinum and LAI was reduced to 81, 65, and 37 %. LAI of H. leporinum was concentrated...

Seasonal Changes of Selected Parameters of CO2 Fixation Biochemistry of Norway Spruce Under the Long-Term Impact of Elevated CO2

O. Urban, M.V. Marek

Photosynthetica 1998, 36(4):533-545 | DOI: 10.1023/A:1007040020512

Twelve-year-old Norway spruce (Picea abies [L.] Karst.) trees were exposed to ambient (AC) or elevated (EC) [ambient + 350 µmol(CO₂) mol^-1] CO₂ concentrations in open-top-chamber (OTC) experiment under the field conditions of a mountain stand. Short-term (4 weeks, beginning of the vegetation season) and long-term (4 growing seasons, end of the vegetation season) effects of this treatment on biochemical parameters of CO₂ assimilation were evaluated. A combination of gas exchange, fluorescence of chlorophyll a, and application of a mathematical model of ribulose-1,5-bisphosphate carboxylase/oxygenase...

Leaf Photosynthesis of the Mangrove Avicennia Germinans as Affected by NaCl

M.A. Sobrado

Photosynthetica 1998, 36(4):547-555 | DOI: 10.1023/A:1007092004582

In leaves of the mangrove species Avicennia germinans (L.) L. grown in salinities from 0 to 40 ‰, fluorescence, gas exchange, and δ¹³C analyses were done. Predawn values of F_v/F_m were about 0.75 in all the treatments suggesting that leaves did not suffer chronic photoinhibition. Conversely, midday F_v/F_m values decreased to about 0.55-0.60 which indicated strong down-regulation of photosynthesis in all treatments. Maximum photosynthetic rate (P _max) was 14.58 ± 0.22 µmol m^-2 s^-1 at 0 ‰ it decreased by 21 and 37 % in...

Effects of Proline and Betaine on Heat Inactivation of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase in Crude Extracts of Rice Seedlings

M.L. Dionisio-Sese, M. Shono, S. Tobita

Photosynthetica 1998, 36(4):557-563 | DOI: 10.1023/A:1007044121420

Activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) in heated crude extracts from seedlings of the rice cultivars Hitomebore and IR28 was investigated in the presence of proline and betaine. Both solutes retarded the inactivation of the enzyme extracted from the leaves of both cultivars at temperature-stress from 35 to 45 °C. At 50 °C, however, betaine was effective in both cultivars. Stabilization of RuBPCO activity was independent of the added solute from 1 to 2 M concentration.

Writing Papers in the Biological Sciences

Z. Šesták

Photosynthetica 1998, 36(4):564 | DOI: 10.1023/A:1007025011851

Structural and Functional Damage Caused by Boron Deficiency in Sunflower Leaves

F. El-Shintinawy

Photosynthetica 1998, 36(4):565-573 | DOI: 10.1023/A:1007096105491

Boron deficiency induced a dramatic inhibition in sunflower plant growth, shown by a reduction in dry mass of roots and shoots of plants grown for 10 d in nutrient solution supplied with 0.02 µM B. This low B supply facilitated the appearance of brown purple pigmentation on the plant leaves over the entire growth period. Compared to B-sufficient (BS) leaves, leakage from B-deficient (BD) leaves was 20 fold higher for potassium, 38 fold for sucrose, and 6 fold for phenolic compounds. High level of membrane peroxidation was detected by measuring peroxidase activities as well as peroxidative products in BD sunflower plants. Soluble and bound peroxidase...

A Cost-Benefit Analysis of Leaves of Eight Australian Savanna Tree Species of Differing Leaf Life-Span

D. Eamus, B. Myers, G. Duff, R. Williams

Photosynthetica 1998, 36(4):575-586 | DOI: 10.1023/A:1007048222329

Cost-benefit analysis of foliar construction and maintenance costs and of carbon assimilation of leaves of differing life-span were conducted using two evergreen, three semi-deciduous, and three deciduous tree species of savannas of north Australia. Rates of radiant-energy-saturated CO₂ assimilation (P _max) and dark respiration were measured and leaves were analysed for total nitrogen, fat, and ash concentrations, and for heat of combustion. Specific leaf area, and leaf N and ash contents were significantly lower in longer-lived leaves (evergreen) than shorter-lived leaves (deciduous) species. Leaves of evergreen species...

Chilling-Induced Photoinhibition in Two Oak Species: Are Evergreen Leaves Inherently Better Protected Than Deciduous Leaves?

J. Cavender-Bares, S. Apostol, I. Moya, J. M. Briantais, F.A. Bazzaz

Photosynthetica 1998, 36(4):587-596 | DOI: 10.1023/A:1007000406399

We compared the sensitivity to cold stress, in terms of photosynthetic capacity and changes in chlorophyll fluorescence of photosystem 2 (PS2), of an evergreen and a deciduous oak species, which co-occur in the southeastern United States. We predicted that the evergreen species, Quercus virginiana, which must endure winter, is likely to have an inherently greater capacity for energy dissipation and to be less susceptible to chilling stress than the deciduous species, Quercus michauxii. Short-term cold stress in both species lead to greater than 50 % reduction in maximum photosynthetic rates, 60-70 % reduction in electron transport, and...

Uniconazole (S-3307) Induced Protection of Abelmoschus Esculentus L. Against Cadmium Stress

S. Purohit, V.P. Singh

Photosynthetica 1998, 36(4):597-599 | DOI: 10.1023/A:1007052423238

In Abelmoschus esculentus L. uniconazole brought about a marked decrease in cadmium-induced loss of chlorophyll and Hill reaction activity, but it did not completely prevent cadmium toxicity.

Origins of Algae and Their Plastids

V. Zachleder

Photosynthetica 1998, 36(4):600 | DOI: 10.1023/A:1007020910942

Inhibition of Glutamine Synthetase Activity by Phosphinothricin Results in Disappearance of the Peak M2 of the Chlorophyll Fluorescence Induction Curve

D.Y. Kornyeyev

Photosynthetica 1998, 36(4):601-604 | DOI: 10.1023/A:1007004507308

The treatment of green algae Chlorococcum lobatum with the herbicide BASTA containing phosphinothricin lead to a significant decrease in the level of peak M2 of the chlorophyll fluorescence induction curve. This agrees with the suggestion that glutamine synthetase activity affects this region of the induction curve.

Clonal Variability in Photosynthetic and Growth Characteristics of Populus Deltoides Under Saline Irrigation

M. Singh, M. Jain, R.C. Pant

Photosynthetica 1998, 36(4):605-609 | DOI: 10.1023/A:1007056524146

Fifty-d-old poplar (Populus deltoides L.) plants were irrigated with 50-200 mM NaCl. 100 and 200 mM NaCl significantly reduced net photosynthetic rate, chlorophyll and carotenoid contents, leaf area, dry matter accumulation, and harvest index (HI) in all tested poplar clones (Bahar, S7C15, and WSL22). Clone S7C15 was more tolerant to salinity than the other clones.

Metal Complexes in Biomimetic Chemical Reactions. N2 Fixation in Solution, Activation and Oxidation of Alkanes, Chemical Models of Photosynthesis

O. Prášil

Photosynthetica 1998, 36(4):610 | DOI: 10.1023/A:1007033313668

Photosynthesis Parameters in Two Cultivars of Mulberry Differing in Salt Tolerance

S. Giridara Kumar, A. Lakshmi, K.V. Madhusudhan, S. Ramanjulu, C. Sudhakar

Photosynthetica 1998, 36(4):611-616 | DOI: 10.1023/A:1007008608217

Three-month-old mulberry (Morus alba L.) cultivars (salt tolerant cv. S1 and salt sensitive cv. ATP) were subjected to different concentrations of NaCl for 12 d. Leaf area, dry mass accumulation, total chlorophyll (Chl) content, net CO₂ assimilation rate (P _N), stomatal conductance (g _s), and transpiration rate (E) declined, and intercellular CO₂ concentration (C _i) increased. The changes in these parameters were dependent on stress severity and duration, and differed between the two cultivars. The tolerant cultivar showed a lesser reduction in P _N...

Protection of Energy Transfer Process in Isolated Phycobilisome by "White Light" from Ultraviolet-B Induced Damage in the Cyanobacterium Spirulina Platensis

S. Rajagopal, Prasanna Mohanty, S.D.S. Murthy

Photosynthetica 1998, 36(4):617-620 | DOI: 10.1023/A:1007060625055

Effect of UV-B (1.9 W m^-2) alone or in combination with supplemental "white light". WL (20 W m^-2) exposure was studied on the energy transfer process of intact phycobilisomes isolated from Spirulina platensis. Exposure of UV-B or supplemental irradiation induced a decrease in room temperature fluorescence intensity and caused a shift towards shorter wavelengths. The low temperature fluorescence measurements showed that UV-B impairs energy transfer from phycocyanin to allophycocyanin B and the extent of damage may be reduced by the exposure to supplemental WL.

Changes in the Non-Photochemical Quenching of Chlorophyll Fluorescence During Aging of Wheat Flag Leaves

S. S. Hong, T. Hong, H. Jiang, D. Q. Xu

Photosynthetica 1998, 36(4):621-625 | DOI: 10.1023/A:1007012709125

Non-photochemical quenching of chlorophyll fluorescence (q_N) and its three components (q_Nf, q_Nm, and q_Ns) in the flag leaves of wheat grown in the field were studied by a fluorometer PAM-2000 on clear days. The diurnal variation patterns of q_N in just fully extended (JFEL) and aging leaves (AL) were similar, but q_Nm declined markedly in JFEL while it remained at a relatively high level in AL under strong sunlight at noon. Furthermore, at midday q_Nf was higher than q_Ns in JFEL, but much lower in AL. The results show the relative contributions of different...

Photosynthesis Bibliography

Photosynthetica 1998, 36(4):626 | DOI: 10.1023/A:1017279730507

Effect of Water Stress on Photosynthesis and Growth in Two Teak Phenotypes

G. Rajendrudu, C.V. Naidu, K. Mallikarjuna

Photosynthetica 1998, 36(4):627-630 | DOI: 10.1023/A:1007064725963

Two teak (Tectona grandis L.f.) phenotypes differing in their leaf length/breadth ratios were subjected to water stress by withholding water supply for three weeks. Growth rates of whole plants, developing leaves (1^st and 2^nd from shoot apices), and 2^nd and 3^rd internodes were higher in broad leaved (BL) phenotype than in narrow leaved (NL) phenotype before and after imposing water stress treatment. However, the effect of water stress on these parameters was higher in the BL phenotype than in the NL one. Diurnal course of net photosynthetic rate (P _N) of 3^rd or 4^th...

The Effect of Abscisic Acid and Methyl Jasmonate on Carbonic Anhydrase Activity in Pea

G.N. Lazova, M.I. Kicheva, L.P. Popova

Photosynthetica 1998, 36(4):631-634 | DOI: 10.1023/A:1007016810034

Short-term (2 h) treatment with 10 µM abscisic acid decreased stomatal conductance and net photosynthetic rate, and increased carbonic anhydrase activity in pea seedlings. The treatment with 10 µM methyl jasmonate did not significantly affect these parameters.

Interactions of Elevated CO2 Concentration and Drought Stress on Photosynthesis in Eucalyptus Cladocalyx F. Muell

K. Palanisamy

Photosynthetica 1998, 36(4):635-638 | DOI: 10.1023/A:1007068826872

Response of net photosynthetic rate (P _N), stomatal conductance (g _s), intercellular CO₂ concentration (c _i), and photosynthetic efficiency (F_v/F_m) of photosystem 2 (PS2) was assessed in Eucalyptus cladocalyx grown for long duration at 800 (C₈₀₀) or 380 (C₃₈₀) µmol mol^-1 CO₂ concentration under sufficient water supply or under water stress. The well-watered plants at C₈₀₀ showed a 2.2 fold enhancement of P _N without any change in g _s. Under both C₈₀₀...

Handbook of Photosynthesis

I. Tichá

Photosynthetica 1998, 36(4):639-640 | DOI: 10.1023/A:1007077028689

UV-B and Biosphere

J. Čatský

Photosynthetica 1998, 36(4):640 | DOI: 10.1023/A:1007081229598