Low-temperature induced changes in the ultrastructure of maize mesophyll chloroplasts strongly depend on the chilling pattern/intensity and considerably differ among inbred and hybrid genotypes

D. Holá, J. Kutík, M. Kočová, O. Rothová

Photosynthetica 2008, 46(3):329 | DOI: 10.1007/s11099-008-0061-5

The ultrastructure and dimensions of chloroplasts in leaf mesophyll cells were quantitatively examined in three parental inbred lines of maize (Zea mays L.) and their four hybrids subjected to two types of four-week low-temperature (LT) treatment: the abrupt onset of chilling temperatures ("severe chilling", SC) and the gradual, more moderate one ("moderate chilling", MC). The relationship between the response of individual genotypes to one or the other type of chilling was analyzed as well as the possibility to predict the behaviour of chloroplasts in hybrids from that of their parents. Although selected parameters of chloroplast ultrastructure...

Effects of chromium toxicity on leaf photosynthetic characteristics and oxidative changes in wheat (Triticum aestivum L.)

D. Subrahmanyam

Photosynthetica 2008, 46(3):339 | DOI: 10.1007/s11099-008-0062-4

Cr(VI) significantly reduced rates of net photosynthesis and transpiration and of stomatal conductance. Cr(VI) did not affect the F_v/F_m ratio of chlorophyll fluorescence implying that the primary photochemical processes in photosystem 2 were not affected. However, the efficiency of excitation capture by open PS2 centres, in vivo quantum yield of PS2 photochemistry, and electron transport rate were significantly reduced by Cr(VI). The coefficient of photochemical quenching was reduced with a concomitant increase in coefficient of non-photochemical quenching, suggesting reduced demand for ATP and NADPH due to inhibition of...

Nitrogen fertilization effects on leaf morphology and evaluation of leaf area and leaf area index prediction models in sugar beet

J. T. Tsialtas, N. Maslaris

Photosynthetica 2008, 46(3):346 | DOI: 10.1007/s11099-008-0063-3

In a two-year experiment (2002-2003), five N application rates [0, 60, 120, 180, and 240 kg(N) ha^-1, marked N₀, N₆₀, N₁₂₀, N₁₈₀, and N₂₄₀, respectively] were applied to sugar beet cv. Rizor arranged in a Randomized Complete Block design with six replications. Leaf shape parameters [leaf area (LA), maximum length (L), maximum width (W), average radial (AR), elongation (EL), and shape factor (SF)] were determined using an image analysis system, and leaf area index (LAI) was non-destructively measured every two weeks, from early August till mid-September (four times). Years, samplings,...

Leaf allometry and prediction of specific leaf area (SLA) in a sugar beet (Beta vulgaris L.) cultivar

J. T. Tsialtas, N. Maslaris

Photosynthetica 2008, 46(3):351-355 | DOI: 10.1007/s11099-008-0064-2

Sugar beet cv. Rizor was grown for five growing seasons (2002-2006) in field conditions in Thessaly, central Greece. A total of 55 samplings took place during the growing seasons and allometric growth of the leaves was monitored. Highly significant (p<0.001) quadratic relationships were found between individual leaf mass (LM), individual leaf area (LA), aboveground dry biomass (ADB), and leaf area index (LAI). Only the LM-LA relationship (LA = 43.444 LM² - 10.693 LM + 118.34) showed a relatively high r ² (0.63) and thus could be used for prediction of LA. Specific leaf area (SLA) was significantly related with...

Effects of root temperature on leaf gas exchange and xylem sap abscisic acid concentrations in six Cucurbitaceae species

Y. P. Zhang, Y. X. Qiao, Y. L. Zhang, Y. H. Zhou, J. Q. Yu

Photosynthetica 2008, 46(3):356 | DOI: 10.1007/s11099-008-0065-1

Roots of six Cucurbitaceae species were exposed to low (14 °C), middle (24 °C), and high (34 °C) temperatures while aerial parts of plants were maintained at ambient temperatures between 23 and 33 °C. The highest dry mass (DM), photon-saturated rate of net photosynthesis (P _Nsat), and stomatal conductance (g _s) were found at 14 °C in figleaf gourd and turban squash plants, at 24 °C in cucumber and melon plants, while bitter melon and wax gourd plants had lower DM, P _Nsat, and g _s at 14 °C than at 24 or 34 °C. Sub-or supra-optimum root temperatures did not induce photoinhibition...

Effect of gamma radiation on mutant induction of Fagopyrum dibotrys Hara

C. F. Jia, A. L. Li

Photosynthetica 2008, 46(3):363 | DOI: 10.1007/s11099-008-0066-0

Agronomic traits, photosynthetic pigments, gas exchange, and chlorophyll (Chl) fluorescence parameters of red stem buckwheat (Fagopyrum dibotrys Hara) mutants induced by γ-radiation were compared with green control at seedling stage. Plant height, number of first-class branches, and rhizome biomass were inhibited significantly (p<0.01). Chl a, Chl b, and Chl a+b contents decreased with elevated dose of γ-rays, while increasing carotenoid content indicated that buckwheat was capable of adjusting to the radiation damage. Decrease in net photosynthetic rate was the result of both stomatal and non-stomatal...

Developmental phase-dependent photosynthetic responses to ultraviolet-B radiation: damage, defence, and adaptation of primary leaves of wheat seedlings

M. K. Pradhan, L. Nayak, P. N. Joshi, P. K. Mohapatra, L. Patro, B. Biswal, U. C. Biswal

Photosynthetica 2008, 46(3):370-377 | DOI: 10.1007/s11099-008-0067-z

Alterations in photosynthetic capacity of primary leaves of wheat seedlings in response to ultraviolet-B (UV-B; 280-320 nm; 60 µmol m^-2 s^-1) exposure alone and in combination with photosynthetically active radiation (PAR; 400-800 nm; 200 µmol m^-2 s^-1) during different phases of leaf growth and development were assessed. UV-B exposure resulted in a phase-dependent differential loss in photosynthetic pigments, photochemical potential, photosystem 2 (PS2) quantum yield, and in vivo O₂ evolution. UV-B exposure induced maximum damage to the photosynthetic apparatus during senescence...

Role of xanthophyll cycle-mediated photoprotection in Arbutus unedo plants exposed to water stress during the Mediterranean summer

R. Baraldi, F. Canaccini, S. Cortes, F. Magnani, F. Rapparini, A. Zamboni, S. Raddi

Photosynthetica 2008, 46(3):378-386 | DOI: 10.1007/s11099-008-0069-x

We analyzed the response of potted strawberry tree (Arbutus unedo L.) seedlings exposed to water stress by withholding water for 10 d (WS). Leaf water potential, net CO₂ assimilation, and stomatal conductance decreased with increasing water deficit. A 30 % reduction of chlorophyll (Chl) content in the antenna complexes was observed in WS-plants. Simultaneously, a decline of photochemical efficiency (F_v/F_m) occurred as a result of an excess of solar radiation energy when carbon assimilation was limited by stomata closure due to soil water deficit. The non-photochemical quenching of Chl fluorescence (Φ_NPQ)...

Effects of the interaction between ozone and carbon dioxide on gas exchange, ascorbic acid content, and visible leaf symptoms in rice leaves

K. Imai, K. Kobori

Photosynthetica 2008, 46(3):387 | DOI: 10.1007/s11099-008-0070-4

Tropospheric ozone (O₃) decreases photosynthesis, growth, and yield of crop plants, while elevated carbon dioxide (CO₂) has the opposite effect. The net photosynthetic rate (P _N), dark respiration rate (R _D), and ascorbic acid content of rice leaves were examined under combinations of O₃ (0, 0.1, or 0.3 cm³ m^-3, expressed as O⁰, O^0.1, O^0.3, respectively) and CO₂ (400 or 800 cm³ m^-3, expressed as C⁴⁰⁰ or C⁸⁰⁰, respectively). The P _N declined immediately after...

Photosynthetic characteristics of a new yellow-green mutant with high photosynthetic rate in rice (Oryza sativa L.)

L. J. Ou, 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(3):395 | DOI: 10.1007/s11099-008-0071-3

Contents of chlorophylls and carotenoids in yellow-green mutant Biao 810S were approximately half those in control type 810S. Biao 810S had fewer grana lamellae and looser structure than 810S, lower volume of starch granules in chloroplasts, but under high temperature and high irradiance the net photosynthetic rate (P _N) of Biao 810S was higher than that of 810S. The chlorophyll fluorescence parameter F_v/F_m of Biao 810S was little higher and photochemical quenching q_P was obviously higher than those of 810S. No significant differences in P _N and biomass were observed in their hybrid...

Glycine betaine improves thylakoid membrane function of tobacco leaves under low-temperature stress

C. Wang, X. L. Ma, Z. Hui, W. Wang

Photosynthetica 2008, 46(3):400-409 | DOI: 10.1007/s11099-008-0072-2

Glycine betaine (GB) is an effective compatible solute that improves the tolerance in plants to various stresses. We investigated the effects of 2 mM GB applied to the roots of a tobacco (Nicotiana tabacum L.) cultivar on enhancing photosynthesis under low-temperature (LT) stress (5/5 °C, 12/12 h, 300 µmol m^-2 s^-1) and in the subsequent recovery (25/18 °C) from the stress. The net photosynthetic rate, intrinsic efficiency measured as the ratio of variable to maximum fluorescence, and actual efficiency of the photochemistry of photosystem 2 as well as the ATPase activity in the thylakoid membrane decreased, and a distinct...

Photosynthesis and photosystem 2 efficiency of two salt-adapted halophytic seashore Cakile maritima ecotypes

W. Megdiche, K. Hessini, F. Gharbi, C. A. Jaleel, R. Ksouri, C. Abdelly

Photosynthetica 2008, 46(3):410-419 | DOI: 10.1007/s11099-008-0073-1

The effects of salinity (0-400 mM NaCl, marked S₀, S₁₀₀, S₂₀₀, and S₄₀₀) on growth, photosynthesis, photosystem 2 (PS2) efficiency, ion relations, and pigment contents were studied in two seashore Cakile maritima ecotypes (Tabarka and Jerba, respectively, sampled from humid and arid bioclimatic areas). Growth of Jerba plants was improved at S₁₀₀ as compared to S₀. Tabarka growth was inhibited by salinity at all NaCl concentrations. Leaf sodium and chloride concentrations increased with medium salinity and were higher in Jerba than in Tabarka plants. Chlorophyll content, net photosynthetic...

Photosynthesis and fluorescence responses of C₄ plant Andropogon gerardii acclimated to temperature and carbon dioxide

V. G. Kakani, G. K. Surabhi, K. R. Reddy

Photosynthetica 2008, 46(3):420-430 | DOI: 10.1007/s11099-008-0074-0

Increase in both atmospheric CO₂ concentration [CO₂] and associated warming are likely to alter Earths' carbon balance and photosynthetic carbon fixation of dominant plant species in a given biome. An experiment was conducted in sunlit, controlled environment chambers to determine effects of atmospheric [CO₂] and temperature on net photosynthetic rate (P _N) and fluorescence (F) in response to internal CO₂ concentration (C _i) and photosynthetically active radiation (PAR) of the C₄ species, big bluestem (Andropogon gerardii Vitman). Ten treatments were comprised...

Time-course of photosynthetic induction in four tropical woody species grown in contrasting irradiance habitats

M. T. Portes, T. H. Alves, G. M. Souza

Photosynthetica 2008, 46(3):431-440 | DOI: 10.1007/s11099-008-0075-z

We investigated the photosynthetic induction time-course in species of different ecological groups grown in contrasting forest irradiance environments, gap and understorey, exposed to different darkness times in order to verify the plant capacity to exploit irradiance heterogeneity. Photosynthetic induction was studied in leaves of Bauhinia forficata and Guazuma ulmifolia (early succession species, ES), and Esenbeckia leiocarpa and Hymenaea courbaril (late succession species, LS). T₅₀ and T₉₀ (time estimates to attain 50 and 90 % of maximum net photosynthetic rate, respectively) varied according to...

Conventional and combinatorial chlorophyll fluorescence imaging of tobamovirus-infected plants

M. Pineda, J. Soukupová, K. Matouš, L. Nedbal, M. Barón

Photosynthetica 2008, 46(3):441-451 | DOI: 10.1007/s11099-008-0076-y

We compared by chlorophyll (Chl) fluorescence imaging the effects of two strains of the same virus (Italian and Spanish strains of the Pepper mild mottle virus - PMMoV-I and-S, respectively) in the host plant Nicotiana benthamiana. The infection was visualized either using conventional Chl fluorescence parameters or by an advanced statistical approach, yielding a combinatorial set of images that enhances the contrast between control and PMMoV-infected plants in the early infection steps. Among the conventional Chl fluorescence parameters, the non-photochemical quenching parameter NPQ was found to be an effective PMMoV infection reporter...

Leaf area estimation by simple measurements and evaluation of leaf area prediction models in Cabernet-Sauvignon grapevine leaves

J. T. Tsialtas, S. Koundouras, E. Zioziou

Photosynthetica 2008, 46(3):452-456 | DOI: 10.1007/s11099-008-0077-x

For two growing seasons (2005 and 2006), leaves of grapevine cv. Cabernet-Sauvignon were collected at three growth stages (bunch closure, veraison, and ripeness) from 10-year-old vines grafted on 1103 Paulsen and SO4 rootstocks and subjected to three watering regimes in a commercial vineyard in central Greece. Leaf shape parameters (leaf area-LA, perimeter-Per, maximum midvein length-L, maximum width-W, and average radial-AR) were determined using an image analysis system. Leaf morphology was affected by sampling time but not by year, rootstock, or irrigation treatment. The rootstock×irrigation×sampling time interaction was significant for all the...

Photosynthesis, chlorophyll fluorescence, and antioxidant enzyme responses of invasive weed Mikania micrantha to Bemisia tabaci infestation

L. L. Zhang, D. Z. Wen

Photosynthetica 2008, 46(3):457-462 | DOI: 10.1007/s11099-008-0078-9

In a glasshouse, Bemisia tabaci infestation largely reduced response of photosynthesis to irradiance and CO₂ concentration of Mikania micrantha compared with the non-infested control (C) ones. The maximum irradiance-saturated photosynthetic rate (P _max) and saturation irradiance (SI) of the infested M. micrantha were only 21.3 % and 6.5 % of the C-plants, respectively. B. tabaci infestation led to the reduction of contents of chlorophyll and carotenoids in M. micrantha, which was accompanied with the decrease of actual photosystem 2 (PS2) efficiency (Φ_PS2), efficiency of...

MPEC: an important gene in the chlorophyll biosynthesis pathway in photosynthetic organisms

H. H. Liu, C. C. Zheng

Photosynthetica 2008, 46(3):321 | DOI: 10.1007/s11099-008-0060-6

One of the least understood enzymatic steps in chlorophyll biosynthesis is the formation of isocyclic ring, which is catalyzed by the Mg-protoporphyrin IX monomethyl ester (MgPME) cyclase that is involved in the conversion of MgPME to protochlorophyllide. Several genes encoding part of this enzyme have been identified and functional analysis of them has been performed. The enzyme plays important roles in higher plants and photosynthetic bacteria. The review focuses on the current knowledge of MgPME cyclase coding genes, with emphasis on their organization, expression pattern, and functional analysis obtained from mutants.

Bock, R.: Cell and Molecular Biology of Plastids

M. Tichý

Photosynthetica 2008, 46(3):377 | DOI: 10.1007/s11099-008-0068-y

Sensitivity of Metasequoia glyptostroboides to ozone stress

Z. Z. Feng, H. Q. Zeng, X. K. Wang, Q. W. Zheng, Z. W. Feng

Photosynthetica 2008, 46(3):463-465 | DOI: 10.1007/s11099-008-0079-8

2-year-old seedlings of Metasequoia glyptostroboides were grown in open top chambers and exposed to four ozone concentrations [O₃] (charcoal-filtered air, CF; 50, 100, and 200 mm³ m^-3) for 25 d. Measurements of growth, leaf chlorophyll (Chl) content, and gas exchange parameters were made before and/or after O₃ exposure. Leaf length, crown width, Chl a/b, net photosynthetic rate, stomatal conductance, and transpiration rate were significantly reduced at 100 and 200 mm³(O₃) m^-3. A remarkable decrease in stomatal conductance also occurred at 50 mm³(O₃)...

Effect of Cd on growth, photosynthetic gas exchange, and chlorophyll fluorescence of wild and Cd-sensitive mutant rice

J. Y. He, Y. F. Ren, C. Zhu, Y. P. Yan, D. A. Jiang

Photosynthetica 2008, 46(3):466 | DOI: 10.1007/s11099-008-0080-2

Growth, photosynthetic gas exchange, and chlorophyll fluorescence characteristics were investigated in wild type (WT) and Cd-sensitive mutant rice (Oryza sativa L.) plants using 50 µM Cd treatment for 12 d followed by a 3-d recovery. Under Cd stress, net dry mass and pigment contents were significantly lower in the mutant plants than in the WT. The mutant had lower net photosynthetic rate (P _N), transpiration rate (E), and stomatal conductance (g _s) than WT rice, however, it had higher intercellular CO₂ concentration (C _i), indicating that non-stomatal factors accounted...

Excess irradiance causes early symptoms of senescence during leaf expansion in photoautotrophically in vitro grown tobacco plants

B. Radochová, I. Tichá

Photosynthetica 2008, 46(3):471-475 | DOI: 10.1007/s11099-008-0081-1

Photosynthetic parameters, growth, and pigment contents were determined during expansion of the fourth leaf of in vitro photoautotrophically cultured Nicotiana tabacum L. plants at three irradiances [photosynthetically active radiation (400-700 nm): low, LI 60 µmol m^-2 s^-1; middle, MI 180 µmol m^-2 s^-1; and high, HI 270 µmol m^-2 s^-1]. During leaf expansion, several symptoms usually accompanying leaf senescence appeared very early in HI and then in MI plants. Symptoms of senescence in developing leaves were: decreasing chlorophyll (Chl) a+b...

Effects of aluminium on photosynthetic performance in Al-sensitive and Al-tolerant maize inbred lines

N. Mihailovic, G. Drazic, Z. Vucinic

Photosynthetica 2008, 46(3):476 | DOI: 10.1007/s11099-008-0082-0

Maize plant inbred lines, one Al-sensitive (B-73) and two Al-tolerant (F-2 and L-2039), were grown hydroponically in the presence of 200 µM Al. After 13 d of growth, root and shoot lengths, photosystem 2 (PS2) activity, chlorophyll (Chl) content, 5-aminolevulinic acid (5-ALA) synthesis rate, chlorophyllase (Chlase) activity, and N, Mg, Fe, and Mn contents in leaves were determined. PS2 activity and Chl content were most severely affected by Al in B-73, but F-2 was almost unaffected. This was in accordance with Al-accumulation in the plants. The observed changes in B-73 coincided with 5-ALA synthesis inhibition, Chlase activation, and leaf deprivation...