Duration of irradiation rather than quantity and frequency of high irradiance inhibits photosynthetic processes in the lichen Lasallia pustulata

M. Barták, H. Vráblíková-Cempírková, J. Štepigová, J. Hájek, P. Váczi, K. Večeřová

Photosynthetica 2008, 46(2):161 | DOI: 10.1007/s11099-008-0027-7

Lichen thalli were exposed to 4 regimes differing in irradiance and duration of irradiation. Photosynthetic efficiency of thalli was monitored by chlorophyll fluorescence parameters and xanthophyll cycle analysis. Maximal quantum yield of photosystem 2 (F_V/F_M) decreased gradually with time in long-term treatment. The effect of additional short-term high irradiance (HI) treatment applied each 24 h was not significant. Nevertheless, short-term HI applied repeatedly on thalli kept in the dark led to a significant decrease of F_V/F_M. Non-photochemical quenching recorded during the long-term treatment corresponded...

Corrections to current approaches used to calculate energy partitioning in photosystem 2

D. Kornyeyev, A. S. Holaday

Photosynthetica 2008, 46(2):170-178 | DOI: 10.1007/s11099-008-0028-6

We analyzed several approaches dealing with the components of non-photochemical energy dissipation and introduced improved versions of the equations used to calculate this parameter. The usage of these formulae depends on the conditions of the sample (acclimation to dark or irradiation, presence or absence of the "actinic light"). The parameter known as "excess" cannot be used as a component of energy partitioning. In reality, this parameter reflects the differences between potential and actual quantum yields of photochemistry.

Growth pattern of Bidens cernua L.: relationships between relative growth rate and its physiological and morphological components

L. Gratani, M. F. Crescente, G. Fabrini, L. Varone

Photosynthetica 2008, 46(2):179 | DOI: 10.1007/s11099-008-0029-5

Seedlings of Bidens cernua L. emerged when mean air temperature was 17.0±1.3 °C. The highest net photosynthetic rate (P _N), 13.8±0.8 µmol(CO₂) m^-2 s^-1, was monitored during the vegetative period (May-August), decreasing on an average by 50 % during flowering (August-September) and during fruiting (September-November) phases. The senescence phase (October-November) was characterised by 79, 58, and 18 % decrease of P _N, chlorophyll content, and leaf area (LA), respectively, from the maximum values. The time span from seedling emergence to the end of fruiting...

Overexpression of tomato chloroplast omega-3 fatty acid desaturase gene alleviates the photoinhibition of photosystems 2 and 1 under chilling stress

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

Photosynthetica 2008, 46(2):185 | DOI: 10.1007/s11099-008-0030-z

In transgenic (TG) tomato (Lycopersicon esculentum Mill.) overexpressed ω-3 fatty acid desaturase gene (LeFAD7) was identified, which was controlled by the cauliflower mosaic virus 35S promoter and induced increased contents of unsaturated fatty acids in thylakoid membrane. Under chilling stress at low irradiance (4 °C, 100 µmol m^-2 s^-1) TG plants with higher linolenic acids (18: 3) content maintained a higher O₂ evolution rate, oxidizable P700 content, and maximal photochemical efficiency (F_v/F_m) than wild type (WT) plants. Low temperature treatment for 6 h resulted in...

Changes in photosynthetic capacity and antioxidant enzymatic systems in micropropagated Zingiber officinale plantlets during their acclimation

Q. Z. Guan, Y. H. Guo, X. L. Sui, W. Li, Z. X. Zhang

Photosynthetica 2008, 46(2):193 | DOI: 10.1007/s11099-008-0031-y

Ginger (Zingiber officinale Rosc.) plantlets were propagated in vitro and acclimated under different photosynthetic photon flux densities (60 and 250 µmol m^-2 s^-1 = LI and HI, respectively). Increases in chlorophyll (Chl) content and Chl a/b ratio were found under both irradiances. In vitro plantlets (day 0) exhibited a low photosynthesis, but chloroplasts from in vitro leaves contained well developed grana and osmiophillic globules. Photoinhibition in leaves formed in vitro was characterized by decrease of photochemical efficiency and quantum efficiency of photosystem 2 photochemistry...

Leaf characteristics and diurnal variation of chlorophyll fluorescence in leaves of the 'bana' vegetation of the amazon region

M. A. Sobrado

Photosynthetica 2008, 46(2):202 | DOI: 10.1007/s11099-008-0033-9

In six dominant species of the Amazonian 'Bana' vegetation, leaf blade characteristics, pigment composition, and chlorophyll (Chl) fluorescence parameters were measured in young and mature leaves under field conditions. Leaf δ¹³C was comparable in the six species, which suggested that both expanding and expanded leaves contained organic matter fixed under similar intercellular and ambient CO₂ concentration (C _i/C _a). High leaf C/N and negative δ¹⁵N values found in this habitat were consistent with the extreme soil N-deficiency. Analysis of Chl and carotenoids showed that...

Responses of the resurrection plant Haberlea rhodopensis to high irradiance

K. Georgieva, S. Lenk, C. Buschmann

Photosynthetica 2008, 46(2):208-215 | DOI: 10.1007/s11099-008-0034-8

The effect of high irradiance (HI) during desiccation and subsequent rehydration of the homoiochlorophyllous desiccation-tolerant shade plant Haberlea rhodopensis was investigated. Plants were irradiated with a high quantum fluence rate (HI; 350 µmol m^-2 s^-1 compared to ca. 30 µmol m^-2 s^-1 at the natural rock habitat below trees) and subjected either to fast desiccation (tufts dehydrated with naturally occurring thin soil layers) or slow desiccation (tufts planted in pots in peat-soil dehydrated by withholding irrigation). Leaf water content was 5 % of the control after 4 d of fast...

Photosynthetic photon flux density, carbon dioxide concentration, and vapor pressure deficit effects on photosynthesis in cacao seedlings

V. C. Baligar, J. A. Bunce, R. C. R. Machado, M. K. Elson

Photosynthetica 2008, 46(2):216 | DOI: 10.1007/s11099-008-0035-7

Independent short-term effects of photosynthetic photon flux density (PPFD) of 50-400 µmol m^-2 s^-1, external CO₂ concentration (C _a) of 85-850 cm³ m^-3, and vapor pressure deficit (VPD) of 0.9-2.2 kPa on net photosynthetic rate (P _N), stomatal conductance (g _s), leaf internal CO₂ concentration (C _i), and transpiration rates (E) were investigated in three cacao genotypes. In all these genotypes, increasing PPFD from 50 to 400 µmol m^-2 s^-1 increased P _N by about...

Seasonal water-use efficiency and chlorophyll fluorescence response in alpha grass (Stipa tenacissima L.) is affected by tussock size

D. A. Ramírez, F. Valladares, F. Domingo, J. Bellot

Photosynthetica 2008, 46(2):222-231 | DOI: 10.1007/s11099-008-0036-6

Twelve randomly chosen Stipa tenacissima L. individuals were grouped into three tussock size classes, small (ST), medium (MT), and large (LT) with 5.6±0.8, 34.1±4.2, and 631.9±85.8 g of dry green foliar matter, respectively, in three plots with different S. tenacissima cover. Instantaneous (WUE_i) and long-term (WUE_l) water-use efficiencies were measured in two seasons of contrasting volumetric soil water content (early winter 21.0±0.8 % and summer 5.8±0.3 %). Maximum photochemical efficiency of photosystem 2 and stomatal conductance in summer assessed the extent of water and irradiance...

Photoprotective function of photorespiration in Reaumuria soongorica during different levels of drought stress in natural high irradiance

J. Bai, D. H. Xu, H. M. Kang, K. Chen, G. Wang

Photosynthetica 2008, 46(2):232 | DOI: 10.1007/s11099-008-0037-5

Diurnal patterns of gas exchange and chlorophyll (Chl) fluorescence parameters of photosystem 2 (PS2) as well as H₂O₂ content were analyzed in Reaumuria soongorica (Pall.) Maxim., a perennial semi-shrub. The rate of photorespiration was estimated by combined measurement of gas exchange and Chl fluorescence. The rate of photorespiration increased with the increasing drought stress (DS). The ratio of carboxylation electron flow to oxygenation electron flow (J_c/J_o) and the maximal photochemical efficiency of PS2 (variable to maximum fluorescence ratio, F_v/F_m) decreased with the increasing...

Genotypic variations in activities of phosphoenolpyruvate carboxylase and correlations with leaf photosynthetic characteristics and crop productivity of cassava grown in low-land seasonally-dry tropics

M. A. El-Sharkawy, Y. Lopez, L. M. Bernal

Photosynthetica 2008, 46(2):238 | DOI: 10.1007/s11099-008-0038-4

Field trials with a large group of cassava germplasm were conducted at the seasonally-dry and hot environments in southwest Colombia to investigate photosynthetic characteristics and production under drought conditions. Measurement of net photosynthetic rate (P _N), photosynthetic nitrogen use efficiency (PNUE), mesophyll conductance to CO₂ diffusion (g _m), and phosphoenolpyruvate carboxylase (PEPC) activity of upper canopy leaves were made in the field. All photosynthetic characteristics were significantly correlated with final dry root yield (Yield). Correlations among the photosynthetic traits...

Diurnal and seasonal trends in photosynthetic performance of Dalbergia sissoo Roxb. and Hardwickia binata Roxb. from a semi-arid ecosystem

S. G. Saraswathi, K. Paliwal

Photosynthetica 2008, 46(2):248-254 | DOI: 10.1007/s11099-008-0041-9

Diurnal and seasonal trends in net photosynthetic rate (P _N), stomatal conductance (g), transpiration rate (E), vapour pressure deficit, temperature, photosynthetic photon flux density, and water use efficiency (WUE) were compared in a two-year-old Dalbergia sissoo and Hardwickia binata plantation. Mean daily maximum P _N in D. sissoo ranged from 21.40±2.60 µmol m^-2 s^-1 in rainy season I to 13.21±2.64 µmol m^-2 s^-1 in summer whereas in H. binata it was 20.04±1.20 µmol m^-2 s^-1...

Role of fructose-1,6-bisphosphatase, fructose phosphotransferase, and phosphofructokinase in saccharide metabolism of four C₃ grassland species under elevated CO₂

E. Nádas, Á. Balogh, F. Kiss, K. Szente, Z. Nagy, R. Martínez-Carrasco, Z. Tuba

Photosynthetica 2008, 46(2):255 | DOI: 10.1007/s11099-008-0042-8

We studied the effects of 15-months of elevated (700 µmol mol^-1) CO₂ concentration (EC) on the CO₂ assimilation rate, saccharide content, and the activity of key enzymes in the regulation of saccharide metabolism (glycolysis and gluconeogenesis) of four C₃ perennial temperate grassland species, the dicots Filipendula vulgaris and Salvia nemorosa and the monocots Festuca rupicola and Dactylis glomerata. The acclimation of photosynthesis to EC was downward in F. rupicola and D. glomerata whereas it was upward in F. vulgaris and S. nemorosa. At EC,...

Seasonal photosynthetic changes in the green-stemmed Mediterranean shrub Calicotome villosa: a comparison with leaves

C. Yiotis, G. K. Psaras, Y. Manetas

Photosynthetica 2008, 46(2):262 | DOI: 10.1007/s11099-008-0045-5

Some photosynthetic attributes of leaves and stems were seasonally followed in the small-leaved, summer-deciduous, green-stemmed Mediterranean shrub Calicotome villosa. Both leaves and stems displayed similar photon energy-saturated photosystem 2 (PS2) efficiencies with a minimum during winter. A second minimum in stems during the leafless summer period could be ascribed to sustained photoinhibition. Yet, stems were slightly inferior in photon capture, resulting partly from lower chlorophyll (Chl) contents and partly from higher reflectance due to pubescence. As a result, photon energy-saturated linear electron transport rates were slightly...

Aartsma, T.J., Matysik, J. (ed.): Biophysical Techniques in Photosynthesis. Volume II

Z. Šesták

Photosynthetica 2008, 46(2):201 | DOI: 10.1007/s11099-008-0032-x

O'Leary, A.: The Essential Guide to Doing Research

Z. Šesták

Photosynthetica 2008, 46(2):261 | DOI: 10.1007/s11099-008-0043-7

Holliday, A.: Doing and Writing Qualitative Research. 2^nd Ed.

Z. Šesták

Photosynthetica 2008, 46(2):261 | DOI: 10.1007/s11099-008-0044-6

Schlegel, R.H.J.: Concise Encyclopedia of Crop Improvement. Institutions, Persons, Theories, Methods, and Histories

D. Holá

Photosynthetica 2008, 46(2):298 | DOI: 10.1007/s11099-008-0053-5

Photosynthetic behaviour of Arabidopsis plants with a Cap Binding Protein 20 mutation under water stress

R. Bacsó, A. Molnár, I. Papp, T. Janda

Photosynthetica 2008, 46(2):268 | DOI: 10.1007/s11099-008-0046-4

Under non-stressed conditions the net photosynthetic rate (P _N) of the mutant plants cbp20 of Arabidopsis was similar to that of the wild type (WT). In response to water deprivation, however, P _N started to decrease later in the mutants and remained substantially higher. Thermoluminescence measurements showed that the lipid peroxidation induced by severe water stress was also less pronounced in the mutant than in the WT. Both soil gravimetric and plant water potential data showed that cbp20 mutants lose water more slowly than the WT plants. The drought-induced decline in F_v/F_m,...

Comparison of the effects of salt-stress and alkali-stress on photosynthesis and energy storage of an alkali-resistant halophyte Chloris virgata

C. W. Yang, A. Jianaer, C. Y. Li, D. C. Shi, D. L. Wang

Photosynthetica 2008, 46(2):273 | DOI: 10.1007/s11099-008-0047-3

Seedlings of Chloris virgata were treated with varying (0-160 mM) salt-stress (SS; 1: 1 molar ratio of NaCl to Na₂SO₄) or alkali-stress (AS; 1: 1 molar ratio of NaHCO₃ to Na₂CO₃). To compare these effects, relative growth rates (RGR), stored energy, photosynthetic pigment contents, net photosynthetic rates, stomatal conductance, and transpiration rates were determined. Both stresses did not change significantly the photosynthetic parameters of C. virgata under moderate stress (below 120 mM). Photosynthetic ability decreased significantly only at high stress (160 mM). Thus C. virgata,...

ATP-sulfurylase activity, photosynthesis, and shoot dry mass of mustard (Brassica juncea L.) cultivars differing in sulfur accumulation capacity

R. Nazar, N. A. Khan, N. A. Anjum

Photosynthetica 2008, 46(2):279 | DOI: 10.1007/s11099-008-0048-2

Sulfur (S) is an essential nutrient element required in a large quantity by mustard. S regulates photosynthesis and plant growth through improving nitrogen (N) acquisition. Mustard cultivars Alankar, Varuna, Pusa Jai Kisan, and SS2 differing in S accumulation capacity calculated as sulfate transport index (STI) were tested for ATP-sulfurylase activity, S and N accumulation, photosynthesis, and shoot dry mass (DM) at 30 and 60 d after sowing (DAS). The activity of ATP-sulfurylase, shoot N content, net photosynthetic rate (P _N), leaf area, and shoot DM of the cultivars were in the order: Pusa Jai Kisan>Alankar>Varuna>SS2. ATP-sulfurylase...

Influence of shading inclined tubular photobioreactor surfaces on biomass productivity of C. sorokiniana

C. U. Ugwu, H. Aoyagi

Photosynthetica 2008, 46(2):283 | DOI: 10.1007/s11099-008-0049-1

Shading of the tubular photobioreactor (PBR) surfaces that diminished solar irradiance to 70 % led to higher biomass productivity and greater accumulation of total chlorophyll and carotenoids compared to the values obtained when the PBR was completely exposed to full sunlight.

Irradiance prior to and during desiccation improves the tolerance to excess irradiance in the desiccated state of the old forest lichen Lobaria pulmonaria

J. Štepigová, Y. Gauslaa, H. Cempírková-Vráblíková, K. A. Solhaug

Photosynthetica 2008, 46(2):286 | DOI: 10.1007/s11099-008-0050-8

Hydrated thalli of the lichen Lobaria pulmonaria were either preconditioned to dim irradiance (DI, 5 µmol m^-2 s^-1) or medium irradiance (MI, 200 µmol m^-2 s^-1) for 6 h. After this 6 h period, the thalli were allowed to desiccate under the two respective irradiances. Thereafter, these dry lichens were exposed to high irradiance (HI, 1 000 µmol m^-2 s^-1) for 60 h. After this HI treatment, the maximal photochemical quantum yield (F_V/F_M) and the de-epoxidation state of xanthophyll cycle pigments (DEPS) were highest in thalli preconditioned to...

Leaf area prediction model for sugar beet (Beta vulgaris L.) cultivars

J. T. Tsialtas, N. Maslaris

Photosynthetica 2008, 46(2):291-293 | DOI: 10.1007/s11099-008-0051-7

In two successive years (2003 and 2004), a set of 16 commercial sugar beet cultivars was established in Randomized Complete Block experiments at two sites in central Greece. Cultivar combination was different between years, but not between sites. Leaf sampling took place once during the growing season and leaf area, LA [cm²], leaf midvein length, L [cm] and maximum leaf width, W [cm] were determined using an image analysis system. Leaf parameters were mainly affected by cultivars. Leaf dimensions and their squares (L², W²) did not provide an accurate model for LA predictions. Using L×W as an independent variable, a...

Evaluation of a leaf area prediction model proposed for sunflower

J. T. Tsialtas, N. Maslaris

Photosynthetica 2008, 46(2):294-297 | DOI: 10.1007/s11099-008-0052-6

Six leaf samplings were conducted in two sunflower (Helianthus annuus L.) hybrids during the 2006 growing season in order to evaluate a simple model proposed for leaf area (LA) estimation. A total of 144 leaves were processed using an image analysis system and LA, maximum leaf width (W) [cm], and midvein length (L) [cm] were measured. Also, LA was estimated using the model proposed by Rouphael et al. (2007). Measured LA was exponentially related with L and W, and the W-LA relationships showed higher r ². Estimated LA was strongly and exponentially related with L. Strong, linear relationships with high r ²...

Effects of clonal integration on photosynthesis of the invasive clonal plant Alternanthera philoxeroides

J. Liu, W. M. He, S. M. Zhang, F. H. Liu, M. Dong, R. Q. Wang

Photosynthetica 2008, 46(2):299 | DOI: 10.1007/s11099-008-0054-4

A greenhouse experiment examined whether clonal integration improves photosynthesis of ramets of alligator weed [Alternanthera philoxeroides (Mart.) Griseb.], a widespread invasive clonal plant in China, in heterogeneous (He) nutrient habitats. The connected pairs of ramets experienced different nutrient levels [high homogeneous (Ho) nutrient, low Ho nutrient, and two He nutrient treatments]. Clonal integration significantly improved the net photosynthetic rate, stomatal conductance, transpiration rate, and minimal and maximal chlorophyll fluorescence of ramets of alligator weed in low nutrient condition. These characteristics may contribute...

Photosynthetic pathway of dominant plant species in the Qaidam Basin: evidence from foliar stable carbon isotope measurement

H. Chen, X. L. Xu, M. H. Song, H. Ouyang

Photosynthetica 2008, 46(2):303 | DOI: 10.1007/s11099-008-0055-3

Foliar δ¹³C values of Calligogum kozlovi and Haloxylon ammodendron ranged from -13.13 to -15.11 ‰, while those of the rest 11 species were in the range of -22.22 to -27.73 ‰. This indicates that two of 13 dominant plant species in the Qaidam Basin possess a C₄ photosynthetic pathway. Significant differences were observed for the average foliar δ¹³C values between C₃ or C₄ plant communities, between grass and shrub communities, even between the same species derived from different sites. Precipitation accounted for the major part of the differences.

Photosynthetic responses to solar UV-A and UV-B radiation in low-and high-altitude populations of Hippophae rhamnoides

Y. Q. Yang, Y. Yao

Photosynthetica 2008, 46(2):307 | DOI: 10.1007/s11099-008-0056-2

Two contrasting sea buckthorn (Hippophae rhamnoides L.) populations from the low (LA) and high (HA) altitudinal regions were employed to evaluate the plant physiological responses to solar UV-A radiation and near-ambient UV-B radiation (UV-B+A) under the sheltered frames with different solar ultraviolet radiation transmittance. LA-population was more responsive to solar UV-A. Some modification caused by UV-A only existed in LA-population, such as significant reduction of leaf size, relative water content, and chlorophyll (Chl) b content as well as δ¹³C elevation, coupled with larger increase of contents of total carotenoids...

Photosynthetic characteristics of an endangered species Camellia nitidissima and its widespread congener Camellia sinensis

X. Wei, Y. S. Jiang, S. Y. Jiang, X. X. Qi, Z. C. Xiong, W. H. Ye, Z. M. Wang

Photosynthetica 2008, 46(2):312-314 | DOI: 10.1007/s11099-008-0057-1

Saturation (SI) and compensation (CI) irradiances [µmol(photon) m^-2 s^-1] were 383.00±18.40 and 12.95±0.42 for wild C. nitidissima (in mid-July) and 691.00±47.39 and 21.91±1.28 for wild C. sinensis, respectively. C. nitidissima is a shade tolerant species, whereas C. sinensis has a wide ecological range of adaptability to irradiance. Both wild and cultivated C. nitidissima demonstrated low maximum net photosynthetic rate, maximum carboxylation rate, maximum electron transfer rate, and SI, which indicated low photosynthesis ability of leaves that were unable to...

Response of senescing rice leaves to flooding stress

S. K. Mishra, L. Patro, P. K. Mohapatra, B. Biswal

Photosynthetica 2008, 46(2):315 | DOI: 10.1007/s11099-008-0058-0

Flooding stress (FS) induced changes in pigment and protein contents and in photochemical efficiency of thylakoid membranes of chloroplasts were investigated during senescence of primary leaves of rice seedlings. Leaf senescence was accompanied by loss in 2,6-dichlorophenolindophenol (DCPIP) photoreduction, rate of oxygen evolution, quantum yield of photosystem 2 with an increase in MDA accumulation, and non-photochemical quenching (NPQ) of chlorophyll fluorescence. These changes were further aggravated when the leaves during this period experienced FS. The increase in NPQ value under stress may indicate photosynthetic adaptation to FS.

Elevated CO₂ concentration enhances the role of the ear to the flag leaf in determining grain yield of wheat

C. W. Zhu, J. G. Zhu, G. Liu, Q. Zeng, Z. B. Xie, J. Pang, Z. Z. Feng, H. Y. Tang, L. Wang

Photosynthetica 2008, 46(2):318-320 | DOI: 10.1007/s11099-008-0059-z

Net photosynthetic rate (P _N) of ear and flag leaf during grain filling stage and grain yield of plants with non-darkened or darkened flag leaf or darkened ear were examined in two different CO₂ concentrations: ambient (AC) and AC+200 µmol mol^-1 (EC). Ear showed much higher enhancement (56 %) of P _N than flag leaf (23 %) under EC. Moreover, CO₂ enrichment shortened the photosynthetic duration of flag leaf relative to ear. In this way the ratio of ear to flag leaf contribution to grain yield increased from 1.18 (AC) to 1.39 (EC).

Influence of insect-infested cotyledons on early seedling growth of Mongolian oak, Quercus mongolica

X. F. Yi, Z. B. Zhang

Photosynthetica 2008, 46(2):247 | DOI: 10.1007/s11099-008-0039-3

Photosynthetic water use efficiency in tree crowns of Shorea beccariana and Dryobalanops aromatica in a tropical rain forest in Sarawak, East Malaysia

Y. Kitahashi, T. Ichie, Y. Maruyama, T. Kenzo, S. Kitaoka, S. Matsuki, L. Chong, T. Nakashizuka, T. Koike

Photosynthetica 2008, 46(2):247 | DOI: 10.1007/s11099-008-0040-x