Effects of salinity on temperature-dependent photosynthetic parameters of a native C₃ and a non-native C₄ marsh grass in the Yangtze Estuary, China

Z. M. Ge, L. Q. Zhang, L. Yuan, C. Zhang

Photosynthetica 2014, 52(4):484-492 | DOI: 10.1007/s11099-014-0055-4

The invasion of Spartina alterniflora along the coasts of China has allowed this C₄ grass to outcompete often much of the native, salt marsh vegetation, such as Phragmites australis (C₃ grass), in the Yangtze Estuary. In this study, native grass, P. australis, and non-native grass, S. alterniflora, were grown in fresh and saline water (moderate salinity of 15‰ and high salinity of 30‰) to compare the effects of salinity on photosynthetic and biochemical parameters in combination with measurement temperatures. The C₄ grass, S. alterniflora, showed a greater CO₂...

Stomatal conductance in Amazonian tree saplings in response to variations in the physical environment

R. A. Marenco, H. C. S. Nascimento, N. S. Magalhães

Photosynthetica 2014, 52(4):493-500 | DOI: 10.1007/s11099-014-0056-3

In juvenile trees growing at the rainforest understory, light is the most limiting factor for growth. It has been assumed that stomata quickly respond to light irrespective of the physical conditions prevailing before leaf illumination. Nevertheless, so far this issue has not been addressed for saplings of Amazonian tree species. The aim of this study was to determine how stomatal conductance (g _s) and photosynthetic parameters of Amazonian saplings respond to diurnal variation in the physical environment and to rainfall seasonality. Light-saturated net photosynthetic rate (P _Nmax) and g _s at light...

Effect of selenium on CO₂ and NO₃^- assimilation under low and adequate nitrogen supply in wheat (Triticum aestivum L.)

R. Hajiboland, N. Sadeghzade

Photosynthetica 2014, 52(4):501-510 | DOI: 10.1007/s11099-014-0058-1

In order to study the mechanisms of Se-mediated growth improvement as related to carbon (C) and nitrogen (N) metabolism, wheat plants were cultivated hydroponically with adequate (4 mM, N_a) or low (1 mM, N_d) N supply and treated with 10 and 50 μM Na₂SeO₄ for six weeks. The Se supplementation enhanced plant biomass; it was significant for shoots of N_a plants at 50 μM Se. Chlorophyll fluorescence parameters were significantly lowered under N_d conditions but restored completely by Se addition reaching values of those in N_a plants. Net CO₂ assimilation rate (P...

A comparison of seasonal foliar chlorophyll change among ecotypes and cultivars of Andropogon gerardii (Poaceae) by using nondestructive and destructive methods

K. L. Caudle, L. C. Johnson, S. G. Baer, B. R. Maricle

Photosynthetica 2014, 52(4):511-518 | DOI: 10.1007/s11099-014-0057-2

Leaf chlorophyll (Chl) concentration can be an indicator of plant health, including photosynthetic potential and nutrient status. In some cases, this measure can indicate the degree to which plants are water-stressed. Traditional methods of measuring Chl concentration have involved a destructive sampling technique: extraction and spectrophotometric analysis. A compatible nondestructive method to measure leaf Chl concentration exists and applies transmittance spectroscopy to plants with a Minolta SPAD-502 meter. These techniques were evaluated by comparing leaf Chl concentration in big bluestem (Andropogon gerardii). Leaves were sampled...

Impact of elevated CO₂ on growth, physiology, yield, and quality of tomato (Lycopersicon esculentum Mill) cv. Arka Ashish

H. Mamatha, N. K. Srinivasa Rao, R. H. Laxman, K. S. Shivashankara, R. M. Bhatt, K. C. Pavithra

Photosynthetica 2014, 52(4):519-528 | DOI: 10.1007/s11099-014-0059-0

Tomato meets the dietary nutrient and antioxidant requirements of diverse populations. Being a C₃ crop and an important vegetable, it is likely to be influenced by increased CO₂ concentrations under climate change situation. This study was conducted to investigate the effects of elevated CO₂ on overall physiology, water relations, growth, yield, and fruit quality of tomato (Lycopersicon esculentum Mill) cv. Arka Ashish. Plants were grown at elevated CO₂ [550 (EC₅₅₀) and 700 (EC₇₀₀) ppm of CO₂] in open top chambers. Increased assimilation rate, decreased stomatal conductance...

Monitoring cashew seedlings during interactions with the fungus Lasiodiplodia theobromae using chlorophyll fluorescence imaging

C. R. Muniz, F. C. O. Freire, F. M. P. Viana, J. E. Cardoso, C. A. F. Sousa, M. I. F. Guedes, R. van der Schoor, H. Jalink

Photosynthetica 2014, 52(4):529-537 | DOI: 10.1007/s11099-014-0061-6

The chlorophyll (Chl) fluorescence imaging technique was applied to cashew seedlings inoculated with the fungus Lasiodiplodia theobromae to assess any disturbances in the photosynthetic apparatus of the plants before the onset of visual symptoms. Two-month-old cashew plants were inoculated with mycelium of L. theobromae isolate Lt19 or Lt32. Dark-adapted and light-acclimated whole plants or previously labelled, single, mature leaf from each plant were evaluated weekly for Chl fluorescence parameters. From 21 to 28 days, inoculation with both isolates resulted in the significantly lower maximal photochemical quantum yield of PSII (F_v/F_m)...

Changes in photosynthesis, pigment composition and glutathione contents in two Antarctic lichens during a light stress and recovery

K. Balarinová, M. Barták, J. Hazdrová, J. Hájek, J. Jílková

Photosynthetica 2014, 52(4):538-547 | DOI: 10.1007/s11099-014-0060-7

Over last decades, several studies have been focused on short-term high light stress in lichens under laboratory conditions. Such studies reported a strong photoinhibition of photosynthesis accompanied by a partial photodestruction of PSII, involvement of photoprotective mechanisms, and resynthetic processes into gradual recovery. In our paper, we applied medium [800 μmol(photon) m^-2 s^-1] light stress to induce negative changes in PSII funcioning as well as pigment and glutathione (GSH) content in two Antarctic fruticose lichen species. Chlorophyll (Chl) fluorescence parameters, such as potential and effective quantum yield...

Fusilade herbicide causes alterations in chloroplast ultrastructure, pigment content and physiological activities of peanut leaves

K. A. Fayez, D. E. M. Radwan, A. K. Mohamed, A. M. Abdelrahman

Photosynthetica 2014, 52(4):548-554 | DOI: 10.1007/s11099-014-0062-5

Fusilade (fluazifop-p-butyl) is one of the herbicides that inhibit acetyl-CoA carboxylase. The exogenous effect of 30, 60, and 90 ppm fusilade on peanut (Arachis hypogaea L. cv. Giza 5) leaves was studied. With increasing fusilade concentration, the peanut leaf chlorosis appeared after 7-10 d. Declined leaf pigment contents confirmed the leaf chlorosis. Electron microscopic observation of the fusilade-treated (FT) leaves revealed disorganization in the ultrastructure of mesophyll cell chloroplasts. An increase of plastoglobuli occurrence within chloroplasts and degenerated grana thylakoids were observed in FT leaves. Fusilade treatments...

Evaluation of photosynthetic performance of wheat cultivars exposed to boron toxicity by the JIP fluorescence test

M. T. Öz, Ö. Turan, C. Kayihan, F. Eyidoğan, Y. Ekmekçi, M. Yücel, H. A. Öktem

Photosynthetica 2014, 52(4):555-563 | DOI: 10.1007/s11099-014-0065-2

The changes in growth and photosynthetic performance of two wheat (Triticum aestivum L.) cultivars (Bolal-2973 and Atay-85) differing in their sensitivity to boron (B) toxicity were investigated under toxic B conditions. Eight-day old seedlings were exposed to highly toxic B concentrations (5, 7.5, and 10 mM H₃BO₃) for 5 and 9 days. Fast chlorophyll a fluorescence kinetics was determined and analysed using JIP test. Growth parameters, tissue B contents, and membrane damage were measured at two stress durations. The photochemical performance of PSII was hindered more in the sensitive cultivar (Atay-85) than that of...

Comparative analysis of drought stress effects on photosynthesis of Eurasian and North African genotypes of wild barley

C. Jedmowski, S. Bayramov, W. Brüggemann

Photosynthetica 2014, 52(4):564-573 | DOI: 10.1007/s11099-014-0064-3

The impact of drought stress (DS) on eight Eurasian and North African genotypes of wild barley (Hordeum spontaneum) was evaluated by analysis of chlorophyll (Chl) a fluorescence fast induction curves using the JIP-test. Three-week-old, pot-grown plants were exposed to a DS treatment by withholding water for nine days. The genotype-specific impairment of the functionality of the photosynthetic electron transport chain was quantified using the relative decline of the performance indices (PI_abs and PI_tot), two key parameters of the JIP-test. The genotypes showing the highest (HOR10164) and lowest (HOR10710) relative...

Toxic effects of erythromycin on photosystem I and II in Microcystis aeruginosa

C. N. Deng, D. Y. Zhang, X. L. Pan

Photosynthetica 2014, 52(4):574-580 | DOI: 10.1007/s11099-014-0063-4

Environmental pollution by antibiotics poses a potential ecological risk to aquatic photosynthetic organisms. In the present study, toxic effects of erythromycin on PSI and PSII were investigated in cyanobacteria culture medium of Microcystis aeruginosa. The activity and electron transport of both photosystems were affected by erythromycin in a concentrationdependent manner. The quantum yield of PSII (Y_II) was reduced at 0.1 mg L^-1 of erythromycin, while the quantum yield of PSI (Y_I) significantly decreased at concentration of 5-25 mg L^-1. The decline of Y_II was accompanied by an increase...

Influence of arbuscular mycorrhiza and phosphorus fertilization on the gas exchange, growth and phosphatase activity of soybean (Glycine max L.) plants

G. M. Abdel-Fattah, A. A. Asrar, S. M. Al-Amri, E. M. Abdel-Salam

Photosynthetica 2014, 52(4):581-588 | DOI: 10.1007/s11099-014-0067-0

We studied the effect of arbuscular mycorrhizal (AM) fungus, Glomus constrictum (Trappe), and soil phosphorus (P) on gas-exchange parameters, growth, and nutrition of soybean plants grown in pots with sterilized soil. Two contrasting concentrations of KH₂PO₄, i.e. no added and 0.5 g(P) kg^-1(soil), were used. Addition of soluble phosphate increased all growth parameters, P and N concentrations, and most of the studied photosynthetic parameters of both the mycorrhizal and nonmycorrhizal plants. The mycorrhizal inoculation significantly increased plant growth responses, P and N concentrations in shoot and...

Effects of supplementary potassium nitrate on growth and gas-exchange characteristics of salt-stressed citrus seedlings

D. Khoshbakht, A. Ghorbani, B. Baninasab, L. A. Naseri, M. Mirzaei

Photosynthetica 2014, 52(4):589-596 | DOI: 10.1007/s11099-014-0068-z

We investigated the effects of supplementary KNO₃ and NaCl on one-year-old, potted Valencia orange (Citrus sinensis) scions grafted on Iranian mandarin Bakraii [Citrus reticulate × Citrus limetta] (Valencia/Bakraii) and Carrizo citrange [C. sinensis × Poncirus trifoliata] (Valencia/Carrizo) rootstocks. After watering plants for 60 days with 50 mM NaCl, the lowest reduction in dry mass, stomatal conductance, and chlorophyll (Chl) content was found in Valencia/Bakraii. Bakraii accumulated more Cl^- and Na⁺ in roots and transferred less to Valencia leaves compared with Carrizo rootstock....

Photosynthesis and chlorophyll fluorescence of infertile and fertile stalks of paired near-isogenic lines in maize (Zea mays L.) under shade conditions

X. M. Zhong, Z. S. Shi, F. H. Li, H. J. Huang

Photosynthetica 2014, 52(4):597-603 | DOI: 10.1007/s11099-014-0071-4

The rainy season affects the development of maize in Liaoning Province in China. Continuous, rainy weather and scant sunlight result in poor pollination, bald tips, and in an abnormally high, barren stalk. Field studies were conducted at the kernel formation stage (3-11 d after silking). Paired, near-isogenic lines of nonbarren stalk (Shennong 98B) and barren stalk (Shennong 98A) were exposed to 38, 60, and 75% shading to investigate changes in photosynthesis and chlorophyll (Chl) fluorescence characteristics under different light intensities. Net photosynthetic rate (P _N), leaf maximum photochemical efficiency of PSII (F_v/F_m),...

Photosynthesis of ozone-sensitive and -resistant Phaseolus vulgaris genotypes under ambient ozone and moderate heat stress

V. Villányi, Z. Ürmös, B. Turk, F. Batič, Z. Csintalan

Photosynthetica 2014, 52(4):604-613 | DOI: 10.1007/s11099-014-0070-5

Physiological responses from sensitive (S156) and resistant (R123) genotypes of ozone bioindicator, snap bean, were investigated after exposing the plants to cumulative, phytotoxic ozone amounts. Daily course of gas-exchange parameters showed delayed stomatal response in S156 leaves to environmental changes comparing to the response of R123 leaves. Potential photosynthetic quantum conversion, Stern-Volmer nonphotochemical quenching (NPQ), and maximum photochemical efficiency of PSII (F_v/F_m) values changed differently in the two genotypes between the first and last measuring days. We concluded that the higher ozone sensitivity...

A portable reflectance-absorptance-transmittance meter for photosynthetic work on vascular plant leaves

R. J. Ritchie, J. W. Runcie

Photosynthetica 2014, 52(4):614-626 | DOI: 10.1007/s11099-014-0069-y

PAM (pulse amplitude modulation) fluorometers can be used to estimate the electron transport rate (ETR) [μmol(e^-) m^-2 s^-1] from photosynthetic yield determinations, provided the absorptance (Abt_λ) of the photoorganism is known. The standard assumed value used for absorptance is 0.84 (leaf absorptance factor, Abt_F). We described a reflectance-absorptancetransmittance (RAT) meter for routine experimental measurements of the actual absorptance of leaves. The RAT uses a red-green-blue (RGB) LED diode light source to measure absorptances at wavelengths suitable for use with PAM fluorometers...

Physiological efficiencies in mini-core peanut germplasm accessions during summer season

A. L. Singh, R. N. Nakar, K. Chakraborty, K. A. Kalariya

Photosynthetica 2014, 52(4):627-635 | DOI: 10.1007/s11099-014-0072-3

In the present study, the physiological efficiencies of 181 mini-core peanut accessions (genotypes) were evaluated according to variability in their physiological performance in the field during summer (2012). Genotypes were categorized into groups of high, medium, and low physiological activity. Thirty-four genotypes showed high net photosynthetic rate (P _N > 33 μmol m^-2 s^-1), 28 genotypes exhibited high stomatal conductance (g _s > 0.54 mmol m^-2 s^-1), 33 genotypes manifested high transpiration rate (E > 11.8 mmol m^-2 s^-1), 30 genotypes...

Proton concentration in the thylakoid membranes can regulate energy distribution between the two photosystems

T. Tongra, S. Bharti, A. Jajoo

Photosynthetica 2014, 52(4):636-640 | DOI: 10.1007/s11099-014-0066-1

The aim of our study was to investigate the role of protons in regulating energy distribution between the two photosystems in the thylakoid membranes. Low pH-induced changes were monitored in the presence of a proton blocker, N,N'-dicyclohexylcarbodiimide (DCCD). When thylakoid membranes were suspended in a low-pH reaction mixture and incubated with DCCD, then a decrease in the fluorescence intensity of photosystem II (PSII) was observed, while no change in the intensity of photosystem I (PSI) fluorescence occurred according to the measured fluorescence emission spectra at 77 K. Since low pH induced distribution of energy from PSII to PSI was inhibited...

Prasanna K. Mohanty

G. C. Papageorgiou

Photosynthetica 2014, 52(4):481-483 | DOI: 10.1007/s11099-015-0075-8

Erratum to: Accumulation of photosynthetic pigments in Larix decidua Mill. and Picea abies (L.) Karst. cotyledons treated with 5-aminolevulinic acid under different irradiation

N. Maximová, Ľ. Slováková

Photosynthetica 2014, 52(4):640 | DOI: 10.1007/s11099-014-0054-5