The peroxidase activity of cytochrome b₆f complex from spinach chloroplasts

X. B. Chen, C. Hou, L. B. Li, T. Y. Kuang

Photosynthetica 2010, 48(1):3-8 | DOI: 10.1007/s11099-010-0002-y

The cytochrome b ₆ f (Cyt b ₆ f) complex, which functions as a plastoquinol-plastocyanin oxidoreductase and mediates the linear electron flow between photosystem II (PSII) and photosystem I (PSI) and the cyclic electron flow around PSI, was isolated from spinach (Spinacia oleracea L.) chloroplasts using n-octyl-β-D-glucopyranoside (β-OG). The preparation was also able to catalyze the peroxidase-like reaction in the presence of hydrogen peroxide (H₂O₂) and guaiacol. The optimal conditions for peroxidase activity of the preparation included: pH 3.6, ionic...

Modeling individual leaf area of rose (Rosa hybrida L.) based on leaf length and width measurement

Y. Rouphael, A. H. Mouneimne, A. Ismail, E. Mendoza-De Gyves, C. M. Rivera, G. Colla

Photosynthetica 2010, 48(1):9-15 | DOI: 10.1007/s11099-010-0003-x

Accurate and nondestructive methods to determine individual leaf areas of plants are a useful tool in physiological and agronomic research. Determining the individual leaf area (LA) of rose (Rosa hybrida L.) involves measurements of leaf parameters such as length (L) and width (W), or some combinations of these parameters. Two-year investigation was carried out during 2007 (on thirteen cultivars) and 2008 (on one cultivar) under greenhouse conditions, respectively, to test whether a model could be developed to estimate LA of rose across cultivars. Regression analysis of LA vs. L and W revealed several models that could be used for estimating...

Light-independent accumulation of essential chlorophyll biosynthesis- and photosynthesis-related proteins in Pinus mugo and Pinus sylvestris seedlings

K. Breznenová, V. Demko, A. Pavlovič, E. Gálová, R. Balážová, J. Hudák

Photosynthetica 2010, 48(1):16-22 | DOI: 10.1007/s11099-010-0004-9

Dark-grown seedlings of Pinus mugo Turra and Pinus sylvestris L. accumulate chlorophyll (Chl) and its precursor protochlorophyllide (Pchlide). Pchlide reduction is a key regulatory step in Chl biosynthesis. In the dark, Pchlide is reduced by light-independent Pchlide oxidoreductase (DPOR) encoded by three plastid genes chlL, chlN, and chlB (chlLNB). To investigate the differences in chlLNB gene expressions, we compared the dark-grown and 24-h illuminated seedlings of P. mugo and P. sylvestris. Expression of these genes was found constitutive in all analyzed samples. We report light-independent...

Physiological and biochemical responses of two tree species in urban areas to different air pollution levels

S. G. Baek, S. Y. Woo

Photosynthetica 2010, 48(1):23-29 | DOI: 10.1007/s11099-010-0005-8

We investigated the physiological and biochemical differences in Pterocarpus indicus and Erythrina orientalis grown in four sites at different pollution levels in the Philippines: Makati, Pasig and Quezon (high pollution levels; HP) located in Metro Manila, and La Mesa Watershed (a non-polluted area; NP). Among these four areas, HP sites had higher net photosynthetic rates (P _N) than NP sites, except for Makati. Among HP sites, Makati and Quezon had the lowest P _N for P. indicus and E. orientalis, respectively. Chlorophyll (Chl) contents were significantly lower in HP than in NP sites....

Overaccumulation of glycine betaine enhances tolerance of the photosynthetic apparatus to drought and heat stress in wheat

G. P. Wang, F. Li, J. Zhang, M. R. Zhao, Z. Hui, W. Wang

Photosynthetica 2010, 48(1):30-41 | DOI: 10.1007/s11099-010-0006-7

To investigate the role of glycine betaine in photosynthesis under stress, a transgenic wheat (Triticum aestivum L.) line T6 overaccumulating glycine betaine and its wild type Shi4185 were used. Seedlings were exposed to conditions of drought (30%, PEG-6000), heat (40°C) and their combination. The results revealed ultrastructural damage to the chloroplast and thylakoid lamellae with the withered phenotype by both drought and heat stress, and the damage was exacerbated by the combination of drought and heat. The appearance of a K step in the typical O-J-I-P curve and the decrease of Hill activity indicated a reduction of oxygen evolving complex...

The photosynthetic pathway of the roots of twelve epiphytic orchids with CAM leaves

C.E. Martin, E.J. Mas, C. Lu, B.L. Ong

Photosynthetica 2010, 48(1):42-50 | DOI: 10.1007/s11099-010-0007-6

The photosynthetic pathway of the roots (both the white velamentous main portions and the green, nonvelamentous tips) was investigated in twelve taxa (natural species and intergeneric hybrid cultivars) of epiphytic orchids having CAM leaves. All organs contained chlorophyll, and the a/b ratios indicate that the organs, especially the roots, are likely shade-adapted. Stable carbon isotope ratios of the tissues were near -15‰ for all organs, a value typical of obligate (constitutive) CAM plants. Values for root tissues were slightly lower (more negative) than those of the leaves. The presence of CAM in the leaves of these orchids did not...

Physiological responses to salinity in Silver buffaloberry (Shepherdia argentea) introduced to Qinghai high-cold and saline area, China

J. Qin, W. Y. Dong, K. N. He, J. Chen, J. Liu, Z. L. Wang

Photosynthetica 2010, 48(1):51-58 | DOI: 10.1007/s11099-010-0008-5

Since 2002, Silver buffaloberry (Shepherdia argentea) has been introduced from North America in order to improve the fragile ecological environment in western China. To elucidate the salt-resistance mechanism of S. argentea, we conducted a test with two-year-old seedlings subjected to 0, 200, 400, and 600 mM NaCl solutions for 30 d. The results showed that significant salt-induced suppression of plant fresh mass (FM) and stem height of S. argentea seedlings occurred only at the highest salinity level (600 mM). Leaf number, plant dry mass (DM), and chlorophyll (Chl) content declined markedly at both 400 and 600 mM. Leaf area (LA)...

Antisense expression of tomato chloroplast omega-3 fatty acid desaturase gene (LeFAD7) enhances the tomato high-temperature tolerance through reductions of trienoic fatty acids and alterations of physiological parameters

X. Liu, J. H. Yang, B. Li, X. M. Yang, Q. W. Meng

Photosynthetica 2010, 48(1):59-66 | DOI: 10.1007/s11099-010-0009-4

We studied how the reductions of trienoic fatty acids (TAs) and increases of dienoic fatty acids (DAs) enhanced high-temperature tolerance in antisense expression of tomato chloroplast omega-3 fatty acid desaturase gene (LeFAD7) transgenic tomato (Lycopersicon esculentum Mill.) plants. In transgenic plants, the content of linolenic acid (18:3) was markedly decreased, while linoleic acid (18:2) was increased correspondingly and the similar changes were observed under high-temperature stress as well. Under high-temperature stress, transgenic plants can maintain a relatively higher level of net photosynthetic rate (P _N)...

Effect of leaf age and position on light-saturated CO₂ assimilation rate, photosynthetic capacity, and stomatal conductance in rubber trees

B. Kositsup, P. Kasemsap, S. Thanisawanyangkura, N. Chairungsee, D. Satakhun, K. Teerawatanasuk, T. Ameglio, P. Thaler

Photosynthetica 2010, 48(1):67-78 | DOI: 10.1007/s11099-010-0010-y

Shoots of the tropical latex-producing tree Hevea brasiliensis (rubber tree) grow according to a periodic pattern, producing four to five whorls of leaves per year. All leaves in the same whorl were considered to be in the same leaf-age class, in order to assess the evolution of photosynthesis with leaf age in three clones of rubber trees, in a plantation in eastern Thailand. Light-saturated CO₂ assimilation rate (A _max) decreased more with leaf age than did photosynthetic capacity (maximal rate of carboxylation, V _cmax , and maximum rate of electron transport, J _max), which...

Effect of hypoxia and post-hypoxia on the fluctuations in contents of malate and citrate, the activity of malic enzyme, and on the intensity of gas exchange in moss gametophores

G. Rut, A. Rzepka, J. Krupa

Photosynthetica 2010, 48(1):79-86 | DOI: 10.1007/s11099-010-0011-x

Mosses are plants of simple anatomical structure and as they occur in habitats characterised not only by major changes in the concentrations of carbon dioxide, they suffer the stress of periodic water shortages or submergence in water. The condition of hypoxia (submergence in water or CaCl₂ solution) prompted the increase in daily fluctuations in malate content, particularly in the gametophores of Polytrichum piliferum Hedw. No significant increases in daily fluctuations of citrate were found in the hypoxia and post-hypoxia conditions. Placing gametophores for 168 h in air with a concentration of CO₂ at ∼ 350 μmol...

Photosynthetic characteristics of diploid honeysuckle (Lonicera japonica Thunb.) and its autotetraploid cultivar subjected to elevated ozone exposure

L. Zhang, H. Xu, J. C. Yang, W. D. Li, G. M. Jiang, Y. G. Li

Photosynthetica 2010, 48(1):87-95 | DOI: 10.1007/s11099-010-0012-9

In order to investigate the effect of chromosome doubling on ozone tolerance, we compared the physiological responses of a diploid honeysuckle (Lonicera japonica Thunb.) and its autotetraploid cultivar to elevated ozone (O₃) exposure (70 ng g^-1, 7 h d^-1 for 31 d). Net photosynthetic rate (P _N) of both cultivars were drastically (P<0.01) impaired by O₃. Although there were significantly positive correlation between P _N and stomatal conductance (g _s) in both cultivars under each treatment, the decreased g _s in O₃...

Limitations of photosynthesis in Phaseolus vulgaris under drought stress: gas exchange, chlorophyll fluorescence and Calvin cycle enzymes

M. C. Dias, W. Brüggemann

Photosynthetica 2010, 48(1):96-102 | DOI: 10.1007/s11099-010-0013-8

In this article, the effects of drought stress (DS) on gas exchange, chlorophyll (Chl) a fluorescence and Calvin cycle enzymes in Phaseolus vulgaris are evaluated. Three-week-old plants were exposed to DS by receiving only so much water every evening to ensure 30% field capacity water content overnight. After three days under these conditions, we observed that DS induced a decline of the CO₂ assimilation. Gas-exchange data showed that the closure of stomata during DS did not lead to a concomitant decline in calculated intercellular CO₂ concentration. Moreover, DS plants showed a reduction of the photochemical Chl...

Photosynthetic light response in three carnivorous plant species: Drosera rotundifolia, D. capensis and Sarracenia leucophylla

B. M. Bruzzese, R. Bowler, H. B. Massicotte, A. L. Fredeen

Photosynthetica 2010, 48(1):103-109 | DOI: 10.1007/s11099-010-0014-7

Photosynthetic properties of carnivorous plants have not been well characterized and the extent to which photosynthesis contributes to carbon gain in most carnivorous plants is also largely unknown. We investigated the photosynthetic light response in three carnivorous plant species, Drosera rotundifolia L. (sundew; circumpolar and native to northern British Columbia, Canada), Sarracenia leucophylla Rafin. ('pitcher-plant'; S.E. United States), and D. capensis L. (sundew; Cape Peninsula, South Africa), using portable gas-exchange systems to explore the capacity for photosynthetic carbon gain in carnivorous plant species. Maximal...

Photoprotective mechanisms in cold-acclimated and nonacclimated needles of Picea glehnii

J. J. Bae, Y. S. Choo, K. Ono, A. Sumida, T. Hara

Photosynthetica 2010, 48(1):110-116 | DOI: 10.1007/s11099-010-0015-6

The response of Picea glehnii, a cold-tolerant species in the boreal zone, to air temperature (T) was investigated for its cold-acclimated needles (i.e. the ones subjected to gradual decrease in T) and nonacclimated needles (i.e. the ones subjected to a sudden decrease in T) were compared under low temperature. Cold-acclimated needles showed a greater increase of zeaxanthin and lutein contents than nonacclimated ones, whereas the nonacclimated needles showed a greater increase of thylakoid-bound ascorbate peroxidase (tAPX) activity than cold-acclimated ones under chilling conditions (after cold acclimation). These results suggest...

Overaccumulation of glycine betaine enhances tolerance to drought and heat stress in wheat leaves in the protection of photosynthesis

G. P. Wang, X. Y. Zhang, F. Li, Y. Luo, W. Wang

Photosynthetica 2010, 48(1):117-126 | DOI: 10.1007/s11099-010-0016-5

We investigated the different responses of wheat (Triticum aestivum L.) plants to drought- (DS) and heat stress (HS), and analyzed the physiological mechanisms of glycine betaine (GB) involved in the improvement of wheat tolerance to the combination of these stresses. The transgenic wheat T6 line was generated by introducing a gene encoding betaine aldehyde dehydrogenase (BADH) into the wild-type (WT) Shi4185 line. The gene was cloned from the Garden Orache plant (Atriplex hortensis L.). Wheat seedlings were subjected to drought stress (30%, PEG-6000), heat stress (40°C), and their combination. Photosynthetic gas exchange, water status...

Photosynthesis, chlorophyll fluorescence, inorganic ion and organic acid accumulations of sunflower in responses to salt and salt-alkaline mixed stress

J. Liu, D. C. Shi

Photosynthetica 2010, 48(1):127-134 | DOI: 10.1007/s11099-010-0017-4

Sunflowers were treated with mixing proportions of NaCl, Na₂SO₄, NaHCO₃, and Na₂CO₃. Effects of salt and saltalkaline mixed stress on growth, photosynthesis, chlorophyll fluorescence, and contents of inorganic ions and organic acids of sunflower were compared. The growth of sunflower decreased with increasing salinity. The contents of photosynthetic pigments did not decrease under salt stress, but their contents decreased sharply under salt-alkaline mixed stress. Net photosynthetic rates, stomatal conductance and intercellular CO₂ concentration decreased obviously, with greater reductions...

mesophyll cell defective1, a mutation that disrupts leaf mesophyll differentiation in sunflower

M. Fambrini, E. Degl'Innocenti, G. Cionini, C. Pugliesi, L. Guidi

Photosynthetica 2010, 48(1):135-142 | DOI: 10.1007/s11099-010-0018-3

Mutants with altered leaf morphology are useful as markers for the study of genetic systems and for probing the leaf differentiation process. One such mutant with deficient greening and altered development of the leaf mesophyll appeared in an inbred line of sunflower (Helianthus annuus L.). The objectives of the present study were to determine the inheritance of the mutant leaf trait and its morphological characterisation. The mutation, named mesophyll cell defective1 (mcd1), has pleiotropic effects and it is inherited as a monogenic recessive. The structure and tissue organization of mcd1 leaves are disrupted. In mcd1...

Photosynthesis, water-use efficiency and δ¹³C of five cowpea genotypes grown in mixed culture and at different densities with sorghum

J. H. J. R. Makoi, S. B. M. Chimphango, F. D. Dakora

Photosynthetica 2010, 48(1):143-155 | DOI: 10.1007/s11099-010-0019-2

A field experiment involving two planting densities (83,333 and 166,666 plants per ha), two cropping systems (monoculture and mixed culture) and five cowpea [Vigna unguiculata L. (Walp.)] genotypes was conducted at Nietvoorbij (33°54S, 18°14E), Stellenbosch, South Africa, to select cowpea material with superior growth and water-use efficiency (WUE). The results showed significantly higher photosynthetic rates, stomatal conductance and transpiration in leaves of plants at low density and in monoculture due to greater chlorophyll (Chl) levels relative to those at high density and in mixed culture. As a result, C concentration in leaves and the...

Björn, L.O. (ed.): Photobiology. The Science of Life and Light.

J. Nauš

Photosynthetica 2010, 48(1):156 | DOI: 10.1007/s11099-010-0020-9

Modular response to salinity in the annual halophyte, Salicornia ramosissima

S. Redondo-Gómez, E. Mateos-Naranjo, R. Parra, M. E. Figueroa

Photosynthetica 2010, 48(1):157-160 | DOI: 10.1007/s11099-010-0021-8

Chlorophyll fluorescence measurements showed that plasticity to salinity in stems of Salicornia ramosissima is expressed at a modular level, so intraplant variation should be considered in further studies.

Christer Sundqvist

Lars Olof Björn, Margareta Ryberg

Photosynthetica 2010, 48(1):1-2 | DOI: 10.1007/s11099-010-0001-z