Responses of four succession tree species in low subtropics to enhanced UV-B radiation in the field

X. A. Cai, S. L. Peng, H. P. Xia, P. Zhao, F. Mason

Photosynthetica 2008, 46(4):490-500 | DOI: 10.1007/s11099-008-0084-y

The tested tree species included pioneer species Acacia mangium, early succession stage species Schima superba, mesophyte intermediate-succession species Machilus chinensis, and shade-tolerant plant or late-succession species Cryptocarya concinna which occur in the lower subtropical forest community. A comparison with the current ambient level of UV-B radiation (UV-B) showed the leaf net photosynthetic rate (P _N), transpiration rate (E), and stomatal conductance (g _s) of the four species ranged from significantly decreased to no significant change. Additionally, the thickness of...

Irradiance stress responses of gas exchange and antioxidant enzyme contents in pariparoba [Pothomorphe umbellata (L.) Miq.] plants

J. A. Marchese, R. S. Mattana, L. C. Ming, F. Broetto, P. F. Vendramini, R. M. Moraes

Photosynthetica 2008, 46(4):501 | DOI: 10.1007/s11099-008-0085-x

We evaluated the growth and development of the medicinal species Pothomorphe umbellata (L.) Miq. under different shade levels (full sun and 30, 50, and 70 % shade, marked as I₁₀₀, I₇₀, I₅₀, and I₃₀, respectively) and their effects on gas exchange and activities of antioxidant enzymes. Photosynthetically active radiation varied from 1 254 µmol m^-2 s^-1 at I₁₀₀ to 285 µmol m^-2 s^-1 at I₃₀. Stomatal conductance, net photosynthetic rate, and relative chlorophyll (Chl) content were maximal in I₇₀ plants. Plants grown...

Up-regulation of cyclic electron flow and down-regulation of linear electron flow in antisense-rca mutant rice

S. H. Jin, D. Wang, F. Y. Zhu, X. Q. Li, J. W. Sun, D. A. Jiang

Photosynthetica 2008, 46(4):506-510 | DOI: 10.1007/s11099-008-0086-9

To investigate how excess excitation energy is dissipated in a ribulose-1,5-bisphospate carboxylase/oxygenase activase antisense transgenic rice with net photosynthetic rate (P _N) half of that of wild type parent, we measured the response curve of P _N to intercellular CO₂ concentration (C _i), electron transport rate (ETR), quantum yield of open photosystem 2 (PS2) reaction centres under irradiation (F_v'/F_m'), efficiency of total PS2 centres (Φ_PS2), photochemical (q_P) and non-photochemical quenching (NPQ), post-irradiation transient increase...

Chlorophyll meter and leaf colour chart to estimate chlorophyll content, leaf colour, and yield of cassava

M. Haripriya Anand, G. Byju

Photosynthetica 2008, 46(4):511-516 | DOI: 10.1007/s11099-008-0087-8

A field experiment was conducted with two cassava cultivars and eight levels of nitrogen to examine the relationship between extractable chlorophyll (Chl) content of cassava leaves and both the Chl meter value (SPAD) and leaf colour chart (LCC) score. The SPAD, LCC, and Chl a+b content were influenced by leaf position, growth stage, cultivar (cv.), and N fertilization. The cvs. and N fertilization had significant effect on SPAD, LCC, and Chl a+b content of youngest fully expanded leaf (leaf 1) blade in most cases. An F-test indicated that common equations pooled across cvs., N fertilization, and growth stages could be used to describe...

Acclimation of photosynthesis to temperature in Arabidopsis thaliana and Brassica oleracea

J. A. Bunce

Photosynthetica 2008, 46(4):517-524 | DOI: 10.1007/s11099-008-0088-7

Plants differ in how much the response of net photosynthetic rate (P _N) to temperature (T) changes with the T during leaf development, and also in the biochemical basis of such changes in response. The amount of photosynthetic acclimation to T and the components of the photosynthetic system involved were compared in Arabidopsis thaliana and Brassica oleracea to determine how well A. thaliana might serve as a model organism to study the process of photosynthetic acclimation to T. Responses of single-leaf gas exchange and chlorophyll fluorescence to CO₂ concentration measured...

Isolation and characterization of photosystem 2 PsbR gene and its promoter from drought-tolerant plant Prosopis juliflora

G. Suja, A. Parida

Photosynthetica 2008, 46(4):525-530 | DOI: 10.1007/s11099-008-0089-6

Prosopis juliflora is a hardy plant tolerant to drought, salinity, extremes of soil pH, and heavy metal stress. We isolated and characterized a photosystem 2 (PS2) gene PsbR (Pj PsbR) and its promoter. Northern analysis for Pj PsbR in P. juliflora leaves under 25 % polyethylene glycol stress showed steady decrease in transcript level at 12, 24, and 48 h after stress application. Under 90 mM H₂O₂ stress, transcript level dropped drastically at 12 h, but increased again compared to the control at 24 h. A 1.7 kb fragment upstream the 5' UTR of this gene (putative promoter) was isolated and analyzed...

Carbon isotope ratios and the variation in the diurnal pattern of malate accumulation in aerial roots of CAM species of Phalaenopsis (Orchidaceae)

H. Motomura, O. Ueno, A. Kagawa, T. Yukawa

Photosynthetica 2008, 46(4):531 | DOI: 10.1007/s11099-008-0090-0

We investigated the carbon isotope ratios and the diurnal pattern of malate accumulation in leaves and aerial roots of eight species of Phalaenopsis grown in greenhouses. The leaves of all the species showed carbon isotope ratios and the diurnal patterns of malate content typical of CAM plants. However, the aerial roots exhibited a large variation in the diurnal pattern of malate content among species and even among plants within the same species, although carbon isotope ratios were always CAM-like values. Some aerial roots showed the typical diurnal pattern of CAM, but others maintained high or low malate contents during a day without fluctuation....

Irreversible changes in barley leaf chlorophyll fluorescence detected by the fluorescence temperature curve in a linear heating/cooling regime

J. Frolec, P. Ilík, P. Krchňák, P. Sušila, J. Nauš

Photosynthetica 2008, 46(4):537-546 | DOI: 10.1007/s11099-008-0091-z

The chlorophyll fluorescence (F) temperature curves in a linear time-temperature heating/cooling regime were used to study heat-induced irreversible F changes in primary green leaves of spring barley (Hordeum vulgare L. cv. Akcent). The leaf segments were heated in a stirred water bath at heating rates of 0.0083, 0.0166, 0.0333, and 0.0500 °C s^-1 from room temperature up to maximal temperature T _m and then linearly cooled to 35 °C at the same rate. The F intensity was measured by a pulse-modulated technique. The results support the existence of the two critical temperatures of irreversible F changes postulated earlier,...

Photosynthetic activity of poikilochlorophyllous desiccation tolerant plant Reaumuria soongorica during dehydration and re-hydration

D. H. Xu, J. H. Li, X. W. Fang, G. Wang, P. X. Su

Photosynthetica 2008, 46(4):547-551 | DOI: 10.1007/s11099-008-0092-y

Diurnal patterns of gas exchange and chlorophyll (Chl) fluorescence parameters of photosystem 2 (PS2) as well as Chl content were analyzed in Reaumuria soongorica (Pall.) Maxim., a perennial semi-shrub during dehydration and rehydration. The net photosynthetic rate (P _N), maximum photochemical efficiency of PS2 (variable to maximum fluorescence ratio, F_v/F_m), quantum efficiency of non-cyclic electron transport of PS2, and Chl content decreased, but non-photochemical quenching of fluorescence and carotenoid content increased in stems with the increasing of drought stress. 6 d after re-hydration, new leaves...

Photosynthetic response of wheat cultivar to long-term exposure to elevated temperature

P. Pushpalatha, P. Sharma-Natu, M. C. Ghildiyal

Photosynthetica 2008, 46(4):552-556 | DOI: 10.1007/s11099-008-0093-x

Wheat (Triticum aestivum L. cv. HD 2285) was grown in control (C) and heated (H) open top chambers (OTCs) for entire period of growth and development till maturity. The mean maximum temperature of the entire period was 3 °C higher in H-compared to C-OTCs. Net photosynthetic rate (P _N) measured at different temperature (20-40 °C) of C-and H-grown plants showed greater sensitivity to high temperature in H-plants. P _N measured at respective growth temperature was lower in H-compared to C-plants. The CO₂ and irradiance response curves of photosynthesis also showed lesser response in H-compared to C-plants....

Photosynthetic response of two tropical liana species grown under different irradiances

M. C. Sanches, I. F. M. Válio

Photosynthetica 2008, 46(4):557-566 | DOI: 10.1007/s11099-008-0094-9

We investigated the characteristics of gaseous exchanges and chlorophyll a fluorescence under different irradiances in two liana species Canavalia parviflora Benth. (Fabaceae) and Gouania virgata Reissk (Rhamnaceae), both of a semi-deciduous tropical forest of Southeast Brazil. We used cultivated plants growing under irradiances of 100, 40, 10, and 1.5 % of the photosynthetic photon flux density (PPFD). Higher net photosynthetic rates (P _N) were observed during early morning under full sunlight. After this, reduced P _N values were recorded due to pronounced stomatal closure. In Canavalia,...

Relationship between net photosynthesis and leaf respiration in Mediterranean evergreen species

L. Gratani, L. Varone, R. Catoni

Photosynthetica 2008, 46(4):567-573 | DOI: 10.1007/s11099-008-0095-8

The relationship between net photosynthetic (P _N) and leaf respiration (R) rates of Quercus ilex, Phillyrea latifolia, Myrtus communis, Arbutus unedo, and Cistus incanus was monitored in the period February 2006 to February 2007. The species investigated had low R and P _N during winter, increasing from March to May, when mean air temperature reached 19.2 °C. During the favourable period, C. incanus and A. unedo had a higher mean P _N (16.4±2.4 µmol m^-2 s^-1) than P. latifolia, Q. ilex, and M. communis (10.0±1.3...

Photosynthesis, water use efficiency, and δ¹³C in two rice genotypes with contrasting response to water deficit

A. J. Pieters, M. Núñez

Photosynthetica 2008, 46(4):574-580 | DOI: 10.1007/s11099-008-0096-7

The effects of water deficit and re-irrigation were studied in glasshouse-grown rice plants (cvs. Cimarrón and Fonaiap 2000) which differ in their susceptibility to water deficit. Relative water content decreased from >90 to 67-69 % and recovered to pre-stress values within 24 h after re-irrigation. The irradiance-saturated rate of photosynthesis (P _sat), transpiration rate (E), and stomatal conductance (g _s) decreased with water deficit. E and g _s decreased similarly in both cultivars, but P _sat was more strongly inhibited in Cimarrón than in Fonaiap 2000. Water...

Changes in electron transport, superoxide dismutase and ascorbate peroxidase isoenzymes in chloroplasts and mitochondria of cucumber leaves as influenced by chilling

W. H. Hu, X. S. Song, K. Shi, X. J. Xia, Y. H. Zhou, J. Q. Yu

Photosynthetica 2008, 46(4):581 | DOI: 10.1007/s11099-008-0098-5

In order to clarify the relationship between chill-induced disturbance in photosynthetic, respiratory electron transport and the metabolism of reactive oxygen species (ROS), leaf gas exchange, chlorophyll fluorescence quenching, respiration, and activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX) were investigated in chloroplasts and mitochondria of cucumber (Cucumis sativus) leaves subjected to a chill (8 °C) for 4 d. Chilling decreased net photosynthetic rate (P _N) and quantum efficiency of photosystem 2 (Φ_PS2), but increased the ratio of Φ_PS2 to the quantum efficiency of...

Photosynthetic characteristics of C₄ trait in chlorina mutant of rice (Oryza sativa L.)

L. J. Ou, W. J. Li, L. F. Tian, Z. Chen, X. J. Dai, L. X. Deng, Y. L. Qiu, H. Li, P. Liu, M. Z. Liang, S. Luan, L. B. Chen

Photosynthetica 2008, 46(4):589 | DOI: 10.1007/s11099-008-0099-4

Biao 810S is a chlorina mutant of the thermosensitive genic male sterile (TGMS) rice. We compared photosynthetic characteristics of these two lines. The contents of chlorophylls and carotenoids in Biao 810S were approximately half of those in 810S. However, the net photosynthetic rate (P _N) of Biao 810S was higher than that of 810S under high irradiance or low concentration of carbon dioxide, and the photon quantum efficiency was higher than that of 810S. The activity of ribulose-1,5-bisphosphate carboxylase/oxygenase in Biao 810S was only 69.80 % of that in 810S, but the activities of phosphoenolpyruvate carboxylase...

Effect of high temperature on photosynthesis and transpiration of sweet corn (Zea mays L. var. rugosa)

J. Ben-Asher, A. Garcia y Garcia, G. Hoogenboom

Photosynthetica 2008, 46(4):595-603 | DOI: 10.1007/s11099-008-0100-2

Four temperature treatments were studied in the climate controlled growth chambers of the Georgia Envirotron: 25/20, 30/25, 35/30, and 40/35 °C during 14/10 h light/dark cycle. For the first growth stage (V3-5), the highest net photosynthetic rate (P _N) of sweet corn was found for the lowest temperature of 28-34 µmol m^-2 s^-1 while the P _N for the highest temperature treatment was 50-60 % lower. We detected a gradual decline of about 1 P _N unit per 1 °C increase in temperature. Maximum transpiration rate (E) fluctuated between 0.36 and 0.54 mm h^-1 (≈5.0-6.5...

Leaf and photosynthetic characteristics of pioneer and forest species in tropical montane habitats

M. A. Sobrado

Photosynthetica 2008, 46(4):604-610 | DOI: 10.1007/s11099-008-0101-1

Gas exchange and chlorophyll a fluorescence measurements of expanding and adult leaves of four plant species were compared under field conditions. The pioneer species (PS) tended to have thinner leaves with lower nitrogen content and higher stomatal density compared to forest species (FS). Expanding leaves featured lower photosynthetic pigment contents and gas exchange capacity than adult leaves consistent with an immature photosynthetic apparatus. At the time of maximum irradiance, sun-exposed leaves of both PS and FS showed alteration of initial, variable, and maximum fluorescence as well as their ratios indicating photoinhibition. However,...

Toxic metal ions in photoautotrophic organisms

T. Kučera, H. Horáková, A. Šonská

Photosynthetica 2008, 46(4):481-489 | DOI: 10.1007/s11099-008-0083-z

We summarize the contemporary understanding of the effects of metal stress on various photosynthetic processes in photoautotrophic organisms and of the defence strategies employed by these organisms to avoid such stress. Cadmium is in the centre of interest of this review, as a non-essential element and important environmental pollutant, but Al, Pb, Hg, As, Cu, and Zn are also considered. Toxic metal ions pollute the environment through anthropogenic activities and affect the quality of plant crop. They represent one of the main abiotic stress factors influencing the health of plants and, as a secondary effect, of animals including man. The review...

New Hart's Rules

Z. Šesták

Photosynthetica 2008, 46(4):580 | DOI: 10.1007/s11099-008-0097-6

Hell, R, Dahl, C., Knaff, D., Leustek, T. (ed.): Sulfur Metabolism in Phototrophic Organisms

Z. Šesták

Photosynthetica 2008, 46(4):626 | DOI: 10.1007/s11099-008-0106-9

Altitude-related changes in activities of carbon metabolism enzymes in Rumex nepalensis

N. Kumar, S. Kumar Vats, S. Kumar, P. S. Ahuja

Photosynthetica 2008, 46(4):611-614 | DOI: 10.1007/s11099-008-0102-0

Activities of some enzymes related to carbon metabolism were studied in different ecotypes of Rumex nepalensis growing at 1 300, 2 250, and 3 250 m above mean sea level. Activities of ribulose-1,5-bisphosphate carboxylase/oxygenase, phosphoenolpyruvate carboxylase, aspartate aminotransferase, and glutamine synthetase increased with altitude, whereas activities of malate dehydrogenase, NAD-malic enzyme, and citrate synthase did not show a significant difference with change in altitude.

Low concentration of bisulfite enhances photosynthesis in tea tree by promoting carboxylation efficiency in leaves

W. J. Yang, H. F. Chen, F. Y. Zhu, M. Q. Hu, D. A. Jiang

Photosynthetica 2008, 46(4):615-617 | DOI: 10.1007/s11099-008-0103-z

Tea tree (Melaleuca alternifolia) canopy was sprayed with low concentration of NaHSO₃ or mixture of NaHSO₃+ KH₂PO₄. The treatments significantly enhanced net photosynthetic rate (P _N), carboxylation efficiency (CE), and the maximum response of P _N to intercellular CO₂ concentration. The enhancement of P _N by foliar application of low concentrations of bisulfite was due to increasing CE relevant to ribulose-1,5-bisphosphate (RuBP) carboxylase/oxygenase activity and regeneration rate of RuBP depending on ATP formation.

Irradiance influences tea leaf (Camellia sinensis L.) photosynthesis and transpiration

T. S. Barman, U. Baruah, J. K. Saikia

Photosynthetica 2008, 46(4):618-621 | DOI: 10.1007/s11099-008-0104-y

Rates of net photosynthesis (P _N) and transpiration (E), and leaf temperature (T_L) of maintenance leaves of tea under plucking were affected by photosynthetic photon flux densities (PPFD) of 200-2 200 µmol m^-2 s^-1. P _N gradually increased with the increase of PPFD from 200 to 1 200 µmol m^-2 s^-1 and thereafter sharply declined. Maximum P _N was 13.95 µmol m^-2 s^-1 at 1 200 µmol m^-2 s^-1 PPFD. There was no significant variation of P _N among PPFD at 1 400-1...

Screening of certain mangroves for photosynthetic carbon metabolic pathway

V. Venkatesalu, A. Senthilkumar, M. Chandrasekaran, K. Kannathasan

Photosynthetica 2008, 46(4):622-626 | DOI: 10.1007/s11099-008-0105-x

The mangroves Rhizophora lamarkii, Ceriops roxburghiana, Bruguiera gymnorrhiza, Aegiceras corniculatum, and Lumnitzera racemosa were screened for their carbon metabolic pathways by measuring net photosynthetic rate (P _N), ¹³C discrimination rate, leaf anatomy, titratable acidity, and activities of phosphoenolpyruvate carboxylase, NADH-malate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, and pyruvate phosphate dikinase. The tested mangroves had a well developed succulence, opening of stomata during day time and closure in the night hours, and absence of diurnal fluctuation of organic...

Photosynthetic and anatomic responses of peanut leaves to cadmium stress

G. R. Shi, Q. S. Cai

Photosynthetica 2008, 46(4):627-630 | DOI: 10.1007/s11099-008-0107-8

Cadmium (Cd) treatments caused an inhibition in the net photosynthetic rate (P _N) of peanut (Arachis hypogaea) plants, due to the reduction of stomatal conductance (g _s) and photosynthetic pigment contents, as well as the alteration in leaf structure. The decrease of the transpiration rate and g _s might result from the Cd-induced xerophyte anatomic features of leaves (i.e. thick lamina, upper epidermis, palisade mesophyll, high palisade to spongy thickness ratio, as well as abundant and small stomata). The decline of P _N was independent of the impairment in photosystem 2.

Chlorophyll fluorescence as a tool for evaluation of drought stress in strawberry

F. Razavi, B. Pollet, K. Steppe, M. C. van Labeke

Photosynthetica 2008, 46(4):631-633 | DOI: 10.1007/s11099-008-0108-7

The effect of water deficit on chlorophyll fluorescence, sugar content, and growth parameters of strawberry (Fragaria×ananassa Duch. cv. Elsanta) was studied. Drought stress caused significant reductions in leaf water potential, fresh and dry masses, leaf area, and leaf number. A gradual reduction of photochemical quenching (q_P) and quantum efficiency (Φ_PS2) was observed under drought stress while non-photochemical quenching (q_N) increased. Maximum efficiency of photosystem 2 (F_v/F_m) was not affected by drought stress.

An evaluation of non-destructive methods to estimate total chlorophyll content

D. Cassol, F. S. P. De Silva, A. R. Falqueto, M. A. Bacarin

Photosynthetica 2008, 46(4):634 | DOI: 10.1007/s11099-008-0109-6

The portable chlorophyll (Chl) meter (CL-01, Hansatech) has been successfully used for a rapid and direct estimation of total Chl content in the leaves of some crops. We compared CL-01 meter readings (Chl value) and Chl contents in leaves of Zea mays, Cucumis sativus, Raphanus sativus, and Ceiba speciosa. Chl index was linearly and positively correlated to Chl content in all the species.

A coupled model of stomatal conductance and photosynthesis for winter wheat

Z. P. Ye, Q. Yu

Photosynthetica 2008, 46(4):637-640 | DOI: 10.1007/s11099-008-0110-0

The model couples stomatal conductance (g _s) and net photosynthetic rate (P _N) describing not only part of the curve up to and including saturation irradiance (I _max), but also the range above the saturation irradiance. Maximum stomatal conductance (g _smax) and I _max can be calculated by the coupled model. For winter wheat (Triticum aestivum) the fitted results showed that maximum P _N (P _max) at 600 µmol mol^-1 was more than at 350 µmol mol^-1 under the same leaf temperature, which can...