Oxygenic photosynthesis-a photon driven hydrogen generator-the energetic/entropic basis of life

P. Hoffmann

Photosynthetica 1997, 35(1):1-11 | DOI: 10.1023/A:1006872110196

Photosynthesis, as a fundamental element in the life process, is integrated in the evolution of living systems on the basis of hydrogen cycles on various hierarchic levels. Conversion of radiant energy enables the oxidation of water, whereby free oxygen accumulates in the atmosphere. Hydrogen is (reversibly) stored in organic materials formed under reductive CO2-fixation and by the incorporation of the other elements, which are necessary for living systems. All endergonic processes in living cells are finally driven by the energy released through the clean recombination of protons and electrons with oxygen to water. Duration of the stored energy and...

Larcher, W.: Ökophysiologie der Pflanzen

J. Čatský, Z. Šesták

Photosynthetica 1997, 35(1):12 | DOI: 10.1023/A:1006858906987

Changes in net photosynthetic rate and chlorophyll fluorescence in potato leaves induced by water stress

P.S. Basu, Ashoo Sharma, N.P. Sukumaran

Photosynthetica 1997, 35(1):13-19 | DOI: 10.1023/A:1006801311105

Net rates of photosynthesis (PN) saturated by irradiance of >500 μmol m-2 s-1 (PAR) significantly decreased in water-stressed potato (Solanum tuberosum L. cv. Kufri Sindhuri) plants. The quantum yield of photochemical energy conversion (Fv/Fm), relative electron transport rate (ETR), and photochemical quenching (Qp) exhibited a parallel decline at high irradiance. A slight decrease in relative water content (RWC) was accompanied by a drastic decline in leaf water potential (Ψw) from -0.2 to -1.0 MPa. Dehydrated leaves showed an increase in the amount of total soluble sugars per unit leaf area which inhibited the photosynthesis in a feedback...

Harris, D.A.: Light Spectroscopy

Z. Šesták

Photosynthetica 1997, 35(1):20 | DOI: 10.1023/A:1006850605170

Effects of CO2 on growth and photosynthesis of Pyrrosia piloselloides (L.) Price gametophytes

Bee-Lian Ong, C.K-K. Koh, Yeow-Chin Wee

Photosynthetica 1997, 35(1):21-27 | DOI: 10.1023/A:1006805427943

The effects of CO2 concentration on spore germination, growth, and net photosynthetic rate (PN) of gametophytes of a tropical epiphytic fern, Pyrrosia piloselloides, were investigated over a 100-d period. Increasing CO2 concentration stimulated spore germination and enhanced gametophytic growth. The appearance of sexual organs and formation of sporophytes were accelerated with higher CO2 during growth. Radiant energy saturated PN and dark respiration rate also increased with increasing CO2 concentrations during growth.

Alley, M.: The Craft of Scientific Writing

Z. Šesták

Photosynthetica 1997, 35(1):28 | DOI: 10.1023/A:1006854822917

Chlorophyll fluorescence parameters characterizing the development of two cacao genotypes infected by witches' broom

I.C.F. Santos, A. A.F. De Almeida, R.R. Valle

Photosynthetica 1997, 35(1):29-39 | DOI: 10.1023/A:1006857412013

Greenhouse-grown susceptible 20-d-old seedlings of Theobroma cacao genotypes Catongo and tolerant genotype SCA6xCatongo were inoculated with a mixture of isolates of Crinipellis perniciosa, the causal agent of witches' broom. The characteristics of chlorophyll a fluorescence emission were monitored during leaf ontogeny using a portable system PAM-2000. In both inoculated and non-inoculated genotypes, significant differences were found for the effective quantum yield values of photosystem (PS) 2 (ΔF/Fm') at the B (7 to 14-d-old), D (21 to 30-d-old), and E (>30-d-old) stages of leaf development, and in quantum yield of the non-cyclic photosynthetic...

Plant Production in Closed Ecosystems

J. Čatský

Photosynthetica 1997, 35(1):40 | DOI: 10.1023/A:1006802822008

Longevity and factors influencing photosynthesis in tea leaves

R. Raj Kumar, L. Manivel, S. Marimuthu

Photosynthetica 1997, 35(1):41-46 | DOI: 10.1023/A:1006809528852

Quadratic relationship between the age of a tea leaf and the net photosynthetic rate (PN) has been found. A progressive increase in PN was recorded for four months. Then the PN slowly declined, yet even seven-month-old tea leaves sustained a low PN. In a tea shoot, the PN increased from the first leaf onwards. Besides the physiological maturity and proximity, photon flux density (PFD) played an important role in reducing the PN. The tea leaf PN was influenced by cultivation procedures which in turn disrupted the quantum of PFD transmitted through the canopy.

Photosynthesis and associated metabolism during development of a Theobroma cacao hybrid with the lethal factor Luteus-Pa

A. A.F. De Almeida, R.R. Valle, P. Serrano Minar

Photosynthetica 1997, 35(1):47-60 | DOI: 10.1023/A:1006861513830

The recessive lethal character Luteus-Pa, expressed as a yellowing of leaves of young seedlings and followed by death approximately 60 d after emergence, presents a 3:1 segregation in crosses and/or selfpollinated plants. We evaluated quantitatively the fluorescence emission of chlorophyll (Chl), gas exchange, and chemical composition of normal and recessive homozygous cacao seedlings of the cross Pa 121×Pa 169. The characteristics of Chl fluorescence kinetics were studied in stages B2, B3, C, D, and E of leaf development, corresponding to plant ages of 9 to 12, 13 to 15, 16 to 20, 21 to 30, and >30 d, respectively. Gas exchanges were measured in...

Differential expression of photosynthesis-related genes of reed ecotypes in response to drought and saline habitats

H.L. Wang, L.M. Hao, J.Q. Wen, C.L. Zhang, H.G. Liang

Photosynthetica 1997, 35(1):61-69 | DOI: 10.1023/A:1006817714739

Three ecotypes of reed (Phragmites communis Trinius), swamp reed (SR), dune reed (DR), and heavy salt meadow reed (HSMR), growing in desert regions of northwest China were simultaneously investigated in their natural state for gas exchange patterns and the expression of three photosynthesis-related genes, cab (the gene for the light-harvesting chlorophyll a/b binding protein, LHC), psbA (the gene for the reaction centre D1 protein of photosystem 2, PS2), and 16S rDNA (the gene for plastid 16S rRNA). Stomatal conductance (gs) and intercellular CO2 concentration (ci) were markedly lower in the two terrestrial ecotypes (DR and HSMR) as compared to SR,...

Impact of simulated acidic rain on growth, photosynthetic pigments, cell metabolites, and leaf characteristics of green gram

G. Kumaravelu, M.P. Ramanujam

Photosynthetica 1997, 35(1):71-78 | DOI: 10.1023/A:1006821931577

Seedlings of green gram (Vigna radiata cv. ADT-1 and CO-5) were exposed to daily showers of simulated acidic rain (H2SO4 : HNO3 : HCl, 4 : 2 : 1, v/v) for 10 d. The effects were analysed after 5 and 10 showers, respectively. Rain of pH 2.5 inhibited seedling growth and biomass accumulation, though in other acidic levels the effects were mostly inconsistent. Both cultivars had high degree of surface wettability indicated by high leaf surface contact angles and water-holding capacity. Treated leaves were thinner with smaller mesophyll cells. Stomatal index and trichome density were lower in contrast to epidermal cell density and stomatal frequency which...

The influence of phosphate deficiency on photosynthesis, respiration and adenine nucleotide pool in bean leaves

M. Mikulska, J. L. Bomsel, A.M. Rychter

Photosynthetica 1997, 35(1):79-88 | DOI: 10.1023/A:1006873932486

The decrease in inorganic phosphate (Pi) content of 10-d-old Phaseolus vulgaris L. plants did not affect rates of photosynthesis (PN) and respiration (RD), leaf growth, and adenylate concentration. Two weeks of phosphate starvation influenced the ATP content and leaf growth more than PN and RD. The ATP concentration in the leaves of 15- and 18-d-old phosphate deficient (-P) plants after a light or dark period was at least half of that in phosphate sufficient (+P, control) plants. Similar differences were found in fresh and dry matter of leaves. However, PN declined to 50 % of control in 18-d-old plants only. Though the RD of -P plants (determined as...

Response of photosynthesis of Pisum sativum to salt stress as affected by methyl jasmonate

M. Velitchkova, I. Fedina

Photosynthetica 1997, 35(1):89-97 | DOI: 10.1023/A:1006878016556

10-5 M methyl jasmonate (JA-Me) treatment itself did not considerably change the 14CO2 fixation, parameters of room temperature chlorophyll fluorescence induction, proline content, and Na+ as well as Cl- accumulation. Salt stress (30 mM NaCl) lead to a decrease of both 14CO2 fixation and relative water content, and to an increase of proline content. Immediate nonvariable fluorescence (F0) also increased and the variable to maximal fluorescence ratio (Fv/Fm) decreased. Pretreatment with JA-Me for 3 d before salt treatment diminished the inhibitory effect of NaCl on the rate of 14CO2 fixation, protein content, and activity and content of ribulose-1,5-bisophosphate...

Differential sensitivity of stomatal and non-stomatal components to NaCl or Na2SO4 salinity in horsegram, Macrotyloma uniflorum (Lam.)

P. Sreenivasulu Reddy, S. Ramanjulu, C. Sudhakar, K. Veeranjaneyulu

Photosynthetica 1997, 35(1):99-105 | DOI: 10.1023/A:1006830100627

14CO2 assimilation rate (P), leaf diffusive conductance (gs), photosynthetic electron flow, and activities of enzymes of Calvin cycle were studied in a horsegram [Macrotyloma uniflorum (Lam.)] in response to salinity induced by NaCl or Na2SO4. A significant reduction in P and gs by both salt treatments was registered. Na2SO4 caused a greater reduction in gs than the NaCl salinity. Studies with isolated chloroplasts confirmed a greater sensitivity to NaCl than to Na2SO4. Salinity inhibited the photosynthetic electron transport. The activity of ribulose-1,5-bisphosphate carboxylase (E.C.4.1.1.39) was under salinity inhibited more than the activities...

A long-lasting photorespiration in CO2-free air, measured as the postirradiation CO2 burst, indicates mobilization of storage photosynthates

Fusheng Xiong, Yuzhu Gao, Ping Song

Photosynthetica 1997, 35(1):107-119 | DOI: 10.1023/A:1006882101535

In CO2-free air, the CO2 postirradiation burst (PIB) in wheat leaves was measured with an IRGA in an open gas exchange system to ascertain its potential role in alleviating photoinhibition of photorespiratory carbon oxidation (PCO) under a CO2 deficiency. A pre-photosynthesized leaf having been transferred into CO2-free air exhibited a typical CO2 PIB following darkening which could last, with a rate substantially higher than that of dark respiration, over a long time period (at least more than 2 h) of continuously alternate irradiation (2 min)-dark (2 min)-light transitions. The rate and the time of PIB maintenance, although unaffected by the exogenous...

Statistical properties of chlorophyll fluorescence induction parameters

D. Lazár, J. Nauš

Photosynthetica 1997, 35(1):121-127 | DOI: 10.1023/A:1006886202444

Parameters of the fast chlorophyll (Chl) fluorescence induction (the O-J-I-P curve) of plants of winter wheat grown in the field canopy were statistically tested for Gaussian distribution. Five different statistical methods showed that the obtained values did not obey the Gaussian distribution law. The presentation of the parameters with the help of the mean and standard deviation masks the information about statistical properties of the values. Thus, we recommend to present the parameters by means of median, quartiles, and minimum and maximum values rather than by means of the mean and standard deviation.

Effects of water deficit on photosynthetic rate and osmotic adjustment in tetraploid wheats

D. Rekika, M.M. Nachit, J.L. Araus, P. Monneveux

Photosynthetica 1997, 35(1):129-138 | DOI: 10.1023/A:1006890319282

Osmotic adjustment, accumulation of soluble saccharides, and photosynthetic gas exchange were studied in five durum wheat (Triticum turgidum L. var. durum) and one wild emmer wheat (Triticum turgidum L. var. dicoccoïdes) cultivars of contrasting drought tolerance and yield stability. Soil water contents (SWC) were 100, 31, 20, and 12 % of maximum capillary capacity. Under mild water stress (SWC 31 to 20 %), osmotic adjustment capacity and high accumulation of saccharides were found in cv. Cham1, a high yielding and drought tolerant cultivar, and in var. dicoccoïdes, while lowest values were noted in the durum wheat landraces Oued-Zenati and...

Photosynthetic rates and vegetative production of Sorghastrum nutans in response to competition at two strip mines and a railroad prairie

V.A. Skeel, D.J. Gibson

Photosynthetica 1997, 35(1):139-149 | DOI: 10.1023/A:1006842420191

The effect of differing environmental conditions on competition for resources was investigated by a comparison of net photosynthetic rate (PN) and vegetative production of Indiangrass [Sorghastrum nutans (L.) Nash.] at two strip mine sites with differing reclamation histories, and a railroad prairie site where this species occurs naturally. The treatment for a competition experiment consisted of tying back all species of neighboring plants around a target plant, and measuring its PN and vegetative performance during the growing season. Environmental variables at each site were also measured during the growing season. Soil bulk density and pH were higher...

Effects of NaCl on photosynthetic pigments, saccharides, and chloroplast ultrastructure in leaves of tomato cultivars

R.A. Khavari-Nejad, Y. Mostofi

Photosynthetica 1997, 35(1):151-154 | DOI: 10.1023/A:1006846504261

In leaves of four tomato (Lycopersicon esculentum Mill.) cultivars (Red Cloud, Floradade, Peto 95, and Scorpio) the contents of chlorophyll (Chl) (a+b), Chl a, and β-carotene decreased due to 100 mM NaCl treatment as compared with those of controls. The contents of soluble sugars and total saccharides were significantly increased in leaves of NaCl-treated plants, but the starch content was not significantly affected. Transmission electron microscopy indicated that in leaves of NaCl-treated plants, the chloroplasts were aggregated, the cell membranes were distorted and wrinkled, and there was no sign of grana and thylakoid structures in chloroplasts.

European Science Foundation Workshop on Green Bacteria and Heliobacteria

J.M. Olson

Photosynthetica 1997, 35(1):155-157 | DOI: 10.1023/A:1006898521099

Mathis, P. (ed.): Photosynthesis: from Light to Biosphere

Z. Šesták

Photosynthetica 1997, 35(1):157-160 | DOI: 10.1023/A:1006811023825