The effects of phenolic acids on the photosynthetic characteristics and growth of Populus × euramericana cv. 'Neva' seedlings

D. F. Xie, G. C. Zhang, X. X. Xia, Y. Lang, S. Y. Zhang

Photosynthetica 2018, 56(4):981-988 | DOI: 10.1007/s11099-018-0818-4  

Populus × euramericana cv. 'Neva' is an important tree species in northern China. In the study, we used its potted oneyear- old seedlings as experimental material and established three treatments (CK, 0.5X, and 1.0X) according to the concentrations of phenolic acids in order to examine the effects of different concentrations on the photosynthetic characteristics and growth of poplar. With increasing concentrations of phenolic acids, the net photosynthetic rate, stomatal limitation, transpiration rate, apparent quantum yield, photochemical quenching coefficient, electron transport rate, chlorophyll content, and total biomass decreased...

The effect of galling aphids feeding on photosynthesis photochemistry of elm trees (Ulmus sp.)

K. Kmieć, K. Rubinowska, W. Michałek, H. Sytykiewicz

Photosynthetica 2018, 56(4):989-997 | DOI: 10.1007/s11099-018-0813-9  

Changes of chlorophyll (Chl) a fluorescence and photosynthetic pigment contents were analysed in galled leaves (visibly damaged and undamaged parts) and intact leaves. The values of minimal fluorescence of the dark-adapted state, maximal quantum yield of PSII photochemistry, effective quantum yield of PSII photochemical conversion, and photochemical quenching coefficient decreased in Ulmus pumila L. leaves galled by Tetraneura ulmi (L.) and in U. glabra Huds. galled by Eriosoma ulmi (L.). Colopha compressa (Koch.) feeding affected these parameters only in damaged parts of U. laevis Pall. galled leaves....

Transcriptome profiling of genes involved in photosynthesis in Elaeagnus angustifolia L. under salt stress

J. Lin, J. P. Li, F. Yuan, Z. Yang, B. S. Wang, M. Chen

Photosynthetica 2018, 56(4):998-1009 | DOI: 10.1007/s11099-018-0824-6  

High salt concentration is a major abiotic stress limiting plant growth and productivity in many areas of the world. Elaeagnus angustifolia L. adapts to adverse environments and is widely planted in the western region of China as a windbreaker and for landscape and soil stabilization. High salt concentrations inhibited photosynthesis of E. angustifolia, but the mechanism is not known. In this paper, RNA-sequencing was used to investigate effects of salt stress on the photosynthetic characteristics of the species. In total, 584 genes were identified and involved in photosynthetic pathways. The downregulation of genes that encode key enzymes...

Variation of photosynthetic characteristics and yield in wild and cultivated species of yams (Dioscorea spp.) from Koraput, India

B. Padhan, D. Panda

Photosynthetica 2018, 56(4):1010-1018 | DOI: 10.1007/s11099-018-0823-7  

Variations in leaf gas-exchange characteristics, PSII activity, leaf pigments, and tuber yield were investigated in seven wild and one cultivated species of Dioscorea from Koraput, India, in order to find out their overall adaptability to the environment. The leaf photosynthetic rate, transpiration, stomatal conductance, water-use efficiency, carboxylation efficiency, and photosynthetic pigments were significantly higher in some wild species compared to the cultivated species. In addition, some wild species showed better photochemical efficiency of PSII, photochemical quenching, and electron transport rate in comparison to cultivated one. Furthermore,...

Morpho-physiological and biochemical responses of muskmelon genotypes to different degree of water deficit

W. A. Ansari, N. Atri, B. Singh, P. Kumar, S. Pandey

Photosynthetica 2018, 56(4):1019-1030 | DOI: 10.1007/s11099-018-0821-9  

Morpho-physiological and biochemical analyses were carried out in eight diverse indigenous muskmelon (Cucumis melo L.) genotypes exposed to different degrees of water deficit (WD). The ability of genotypes MM-7, and especially MM-6, to counteract better the negative effect of WD was associated with maintaining higher relative water content (RWC), photosynthetic rate, efficiency of PSII, and photosynthetic pigments compare to other genotypes. Furthermore, MM-6 showed a better ability to maintain cellular homeostasis than the others. It was indicated by a stimulated antioxidative defense system, i.e., higher activities of antioxidant enzymes,...

Photosynthetic and yield responses of rice (Oryza sativa L.) to different water management strategies in subtropical China

X. H. Wu, W. Wang, X. L. Xie, C. M. Yin, K. J. Xie

Photosynthetica 2018, 56(4):1031-1038 | DOI: 10.1007/s11099-018-0817-5  

An experiment was performed to study gas exchange and chlorophyll fluorescence responses of rice (Oryza sativa L.) to various regimes, such as flooding-midseason drying-flooding (FDF), flooding-midseason drying-saturation (FDS), and flooding-rain-fed (FR) regimes. Compared to FDF, FR resulted in an obvious decrease in net photosynthetic rate (P_N), due to the decrease in stomatal conductance and the increase in stomatal limitation. In contrast, FDS plants did not suffer stomatal limitation and had comparable P_N with FDF plants. For diurnal light-saturated electron transport rate and saturation irradiance, FDF...

Effect of ammonium/nitrate ratio on pak choi (Brassica chinensis L.) photosynthetic capacity and biomass accumulation under low light intensity and water deficit

H.Q. Shang, G.M. Shen

Photosynthetica 2018, 56(4):1039-1046 | DOI: 10.1007/s11099-018-0815-7  

We conducted a hydroponic experiment in order to study effects of the ammonium/nitrate ratio (0:15, 5:10, 7.5:7.5, and 10:5) on photosynthetic characteristics and biomass accumulation in Brassica chinensis under low light intensity and water stress. Results showed that net photosynthetic rate, transpiration rate, intrinsic water-use efficiency, stomatal conductance, intercellular CO₂ concentration, effective quantum yield of PSII photochemistry, electron transport rate, and nonphotochemical quenching were lower in the treatment (low light intensity and water deficit) than those in the control, whereas stomatal limitation increased....

Silicon nutrition mitigates salinity stress in maize by modulating ion accumulation, photosynthesis, and antioxidants

W. U. D. Khan, T. Aziz, M. A. Maqsood, M. Farooq, Y. Abdullah, P. M. A. Ramzani, H. M. Bilal

Photosynthetica 2018, 56(4):1047-1057 | DOI: 10.1007/s11099-018-0812-x  

Silicon is known to improve resistance against salinity stress in maize crop. This study was conducted to evaluate the influence of silicon application on growth and salt resistance in maize. Seeds of two maize genotypes (salt-sensitive 'EV 1089' and salt-tolerant 'Syngenta 8441') were grown in pots containing 0 and 2 mM Si with and without 50 mM NaCl. After detailed investigation of ion concentrations in different maize organs, both genotypes were further selected in hydroponic experiment on basis of their contrasting response to salinity stress. In the second experiment, pre-germinated seedlings were transplanted into nutrient solution with 0 and...

Photosynthesis and physiology responses of paired near-isogenic lines in waxy maize (Zea mays L.) to nicosulfuron

J. Wang, X. M. Zhong, X. L. Lv, Z. S. Shi, F. H. Li

Photosynthetica 2018, 56(4):1059-1068 | DOI: 10.1007/s11099-018-0816-6  

Nicosulfuron is a post-emergence herbicide used for weed control in fields of maize (Zea mays L.). We used a pair of nearly isogenic inbred lines, SN509-R (nicosulfuron-resistant) and SN509-S (nicosulfuron-sensitive), to study the effect of nicosulfuron on waxy maize seedling. After the nicosulfuron treatment, net photosynthetic rate, stomatal conductance, transpiration rate, leaf maximum photochemical efficiency of PSII, photochemical quenching of chlorophyll fluorescence, and the actual photochemical efficiency of PSII were significantly lower in SN509-S than those of SN509-R, contrary to intercellular CO₂ concentration, stomatal...

Photosynthetic, physiological and biochemical events associated with polyethylene glycol-mediated osmotic stress tolerance in taro (Colocasia esculenta L. Schott)

M. R. Sahoo, M. Dasgupta, P. C. Kole, A. Mukherjee

Photosynthetica 2018, 56(4):1069-1080 | DOI: 10.1007/s11099-018-0819-3  

Six genotypes of taro (Colocasia esculenta L. Schott) were evaluated under in vitro and in vivo polyethylene glycol (PEG-6000)-mediated osmotic stress conditions. A significant variation in growth response was observed among the taro genotypes under in vitro-induced stress conditions. In vivo results indicated a significant effect of osmotic stress on photosynthetic parameters, such as net photosynthetic rate, transpiration rate, stomatal conductance, stomatal resistance, internal CO₂ concentration, carboxylation efficiency, and transpiration efficiency on the tested genotypes at the tuberization stage....

Effects of GeO₂ on chlorophyll fluorescence and antioxidant enzymes in apple leaves under strong light

Z. B. Wang, Y. F. Wang, J. J. Zhao, L. Ma, Y. J. Wang, X. Zhang, Y. T. Nie, Y. P. Guo, L. X. Mei, Z. Y. Zhao

Photosynthetica 2018, 56(4):1081-1092 | DOI: 10.1007/s11099-018-0807-7  

In this study, we chose apple leaf as plant material and studied effects of GeO₂ on operation of photosynthetic apparatus and antioxidant enzyme activities under strong light. When exogenous GeO₂ concentration was below 5.0 mg L^-1, maximum photochemical quantum yield of PSII and actual quantum yield of PSII photochemistry increased significantly compared with the control under irradiances of 800 and 1,600 μmol(photon) m^-2 s^-1. Photosynthetic electron transport chain capacity between Q_A-Q_B, Q_A-PSI acceptor, and Q_B-PSI acceptor showed a trend of rising...

Physiological responses of Pterocladiella capillacea (Rhodophyta, Gelidiales) under two light intensities

T.B. Harb, A. Nardelli, F. Chow

Photosynthetica 2018, 56(4):1093-1106 | DOI: 10.1007/s11099-018-0805-9  

Macroalgae must be able to survive in conditions of different light intensities with no damage to their physiological performance or vital processes. Irradiance can stimulate the biosynthesis of certain photoprotective compounds of biotechnological interest, such as pigments and proteins. Pterocladiella capillacea is a shade-grown alga, which play a role key in the balance of marine ecosystems. In addition, it is considered one of the best sources of bacteriological agar and agarose with a wide pharmacological potential. In order to evaluate the photosensitivity in P. capillacea under 60 (control) and moderate light intensity of 300 μmol(photon)...

Diurnal temperature-related variations in photosynthetic enzyme activities of two C₄ species of Chenopodiaceae grown in natural environment

T. Y. Orujova, S. M. Bayramov, U. A. Gurbanova, H. G. Babayev, M. N. Aliyeva, N. M. Guliyev, Y. M. Feyziyev

Photosynthetica 2018, 56(4):1107-1112 | DOI: 10.1007/s11099-018-0804-x  

The effects of the diurnal variations in ambient temperature on some C₃ and C₄ enzymes in the Salsola dendroides and Suaeda altissima species of Chenopodiaceae family were studied during the intensive vegetation period. Activities of phosphoenolpyruvate carboxylase (PEPC) and cytosolic aspartate aminotransferase (AsAT) were shown to decrease in both species in the afternoon and evening. The activity of the mitochondrial AsAT decreased in S. altissima, remained relatively constant in S. dendroides during the day. The activity of alanine aminotransferase was high in the S. dendroides species...

Effect of light quality on leaf photosynthetic characteristics and fruit quality of peach (Prunus persica L. Batch)

B.-B. Zhang, J.-L. Xu, M. Zhou, D.-H. Yan, R.-J. Ma

Photosynthetica 2018, 56(4):1113-1122 | DOI: 10.1007/s11099-018-0820-x  

Different light filters affect leaf photosynthetic features and fruit quality. Consequently, selecting the appropriate covering filter for rain-shelter cultivation of peaches is a key part of successful production. We used a late-maturing peach variety 'Xiahui 8' to study differences in leaf photosynthetic features, chlorophyll fluorescence characteristics, and fruit quality under neutral, red, yellow, green, and blue filter, with natural light as control. The results showed that the leaf photosynthetic ability and internal quality under the neutral filter treatment were elevated compared with the control, and the appearance color was the same as the...

Comparative chloroplast proteome analysis of exogenously supplied trehalose to wheat seedlings under heat stress

Y. Luo, H. Y. Liu, Y. Z. Fan, W. Wang, Y. Y. Zhao

Photosynthetica 2018, 56(4):1123-1133 | DOI: 10.1007/s11099-018-0808-6  

The aim of our study was to investigate the underlying molecular mechanisms of exogenously supplied trehalose affecting wheat photosynthesis under heat stress. The amount of ATP synthase (ATPase), oxygen-evolving enhancer protein (OEE), PsbP, Rubisco, chloroplast fructose-bisphosphate aldolase (FBPA), and ferredoxin-NADP(H) oxidoreductase (FNR) were downregulated, while PSI reaction center subunits were upregulated under heat stress. However, in the trehalose-pretreated groups, the amount of FNR, cytochrome b₆f complex, PSI reaction center subunits, ATPase, FBPA, and Rubisco were upregulated under normal growth conditions and...

Autumnal leaf abscission of sugar maple is not delayed by atmospheric CO₂ enrichment

L. Li, W. J. Manning, X. K. Wang

Photosynthetica 2018, 56(4):1134-1139 | DOI: 10.1007/s11099-018-0802-z  

To investigate the effects of atmospheric CO₂ enrichment on physiology and autumnal leaf phenology, we exposed 3-year-old sugar maple (Acer saccharum Marsh.) seedlings to 800 (A8), 600 (A6), and 400 μL(CO₂) L^-1 (AA) in nine continuous stirred tank reactor (CSTR) chambers during the growing season of 2014. Leaf abscission timing, abscised leaf area percentages, leaf number, light-saturated net photosynthetic rate (P_Nmax), leaf area, accumulative growth rates, and biomass were determined and assessed. The results suggested the following: (1) no significant differences were found in the...

Physio-anatomical responses of tobacco under caffeine stress

R. Alkhatib, B. Alkhatib, L. Al-Eitan, N. Abdo, M. Tadros, E. Bsoul

Photosynthetica 2018, 56(4):1140-1146 | DOI: 10.1007/s11099-018-0798-4  

Caffeine, a purine alkaloid, is reported to act both as an inducer or inhibitor to plant growth in various species. The aim of this study was to examine the effect of exogenous caffeine on tobacco (Nicotiana tabacum) plants, a plant that does not naturally synthesise caffeine. A hydroponic experiment was carried out in a growth chamber for 14 d using Hoagland's solution supplemented with 0 (control), 25, 50, 100, 1,000; and 5,000 μM caffeine. None of the investigated caffeine concentrations significantly decreased the net photosynthetic rate except the highest concentrations of 1,000 and 5,000 μM. Light microscopy of thick-sectioned roots...

The effects of lead on photosynthetic performance of waxberry seedlings (Myrica rubra)

B. He, M. Gu, X. Wang, X. He

Photosynthetica 2018, 56(4):1147-1153 | DOI: 10.1007/s11099-018-0800-1  

The photosynthesis was investigated 30 d after Pb treatment in Myrica rubra seedlings. The Pb treatment resulted in significantly increased Pb concentrations in shoots. Low Pb concentration exposure (≤2 mM) reduced the net photosynthetic rate (P_N), transpiration rate (E), and stomatal conductance (gs) without affecting the intercellular CO₂ concentration (C_i), chlorophyll (Chl) content, and Chl fluorescence parameters. At 10 d after severe Pb treatment (≥4 mM), P_N was inhibited and accompanied by Chl damage, while at 30 d, the inhibition of P_N...

H₂O₂-induced acclimation of photosystem II to excess light is mediated by alternative respiratory pathway and salicylic acid

Q. Z. Hou, Y. P. Wang, J. Y. Liang, L. Y. Jia, H. Q. Feng, J. Wen, N. Ehmet, J. Y. Bai

Photosynthetica 2018, 56(4):1154-1160 | DOI: 10.1007/s11099-018-0806-8  

Acclimation to excess light is required for optimizing plant performance under natural environment. The present work showed that the treatment of Arabidopsis leaves with exogenous H₂O₂ can increase the acclimation of PSII to excess light. Treatments with H₂O₂ also enhanced the capacity of the mitochondrial alternative respiratory pathway and salicylic acid (SA) content. Our work also showed that the lack in alternative oxidase (AOX1a) in AtAOX1a antisense line and the SA deficiency in NahG (salicylate hydroxylase gene) transgenic mutant attenuated the H₂O₂-induced acclimation...

Chlorophyll fluorescence and gas exchange measurements in field research: an ecological case study

S. F. Bucher, M. Bernhardt-Römermann, C. Römermann

Photosynthetica 2018, 56(4):1161-1170 | DOI: 10.1007/s11099-018-0809-5  

We tested whether cheap and quick chlorophyll (Chl) fluorescence can be used in ecophysiological field studies as proxies for gas-exchange measurements. We measured net photosynthetic rate at saturating irradiance and ambient atmospheric CO₂ concentrations (P_Nsat), maximum carboxylation rate (V_cmax), maximum quantum yield of PSII (F_v/F_m), the performance index (PIabs), leaf nitrogen (Narea), and carbon isotope discrimination (Δ¹³C) within four herbaceous species along two elevational gradients. We analysed the relationship between Chl fluorescence and gas-exchange parameters...

Thermal acclimation of the temperature dependence of the V_Cmax of Rubisco in quinoa

J.A. Bunce

Photosynthetica 2018, 56(4):1171-1176 | DOI: 10.1007/s11099-018-0799-3  

Changes in the temperature dependence of the maximum carboxylation capacity (V_Cmax) of Rubisco during thermal acclimation of P_N remain controversial. I tested for acclimation of the temperature dependence of V_Cmax in quinoa, wheat, and alfalfa. Plants were grown with day/night temperatures of 12/6, 20/14, and 28/22°C. Responses of PN to substomatal CO₂ (C_i) and CO₂ at Rubisco (C_c) were measured at leaf temperatures of 10-30°C. V_Cmax was determined from the initial slope of the P_Nvs. C_i or C_c...

Relationship between photosynthetic rate, water use and leaf structure in desert annual and perennial forbs differing in their growth

L. Gonzalez-Paleo, D.A. Ravetta

Photosynthetica 2018, 56(4):1177-1187 | DOI: 10.1007/s11099-018-0810-z  

Specific leaf area (SLA) is a key trait to screen plants for ecological performance and productivity; however, the relationship between SLA and photosynthesis is not always up-scalable to growth when comparing multiple species with different life cycles. We explored leaf anatomy in annual and perennial species of Physaria, and related it to photosynthesis and water loss. The annual Physaria gracilis had higher SLA, thinner leaves, and lower investment in protective tissues, than perennial P. mendocina. Physaria angustifolia (annual), and P. pinetorum (perennial) showed intermediate values. Both perennials had a thicker...

Physiological changes and growth promotion induced in poplar seedlings by the plant growth-promoting rhizobacteria Bacillus subtilis JS

J. H. Jang, S. -H. Kim, I. Khaine, M. J. Kwak, H. K. Lee, T. Y. Lee, W. Y. Lee, S. Y. Woo

Photosynthetica 2018, 56(4):1188-1203 | DOI: 10.1007/s11099-018-0801-0  

This study aimed to determine the effects of plant growth-promoting rhizobacteria Bacillus subtilis JS on the growth and physiological changes of Populus euramericana and Populus deltoides × P. nigra. Poplar seedlings were treated with B. subtilis JS and their growth was monitored for up to 120 d. Three different types of treatments [control, B1 (B. subtilis:double-distilled water, 1:100, v/v), and B2 (1:50)] were established. B. subtilis JS enhanced seedling height by 62% and total biomass by 37% after 120 d. Physiologically, the photosynthetic rate increased by 54%, and the total chlorophyll (Chl) content,...

Effects of exogenous calcium on mesophyll cell ultrastructure, gas exchange, and photosystem II in tobacco (Nicotiana tabacum Linn.) under drought stress

W. Hu, S. B. Tian, Q. Di, S. H. Duan, K. Dai

Photosynthetica 2018, 56(4):1204-1211 | DOI: 10.1007/s11099-018-0822-8  

The effects of calcium chloride solution (10 mmol L^-1) on mesophyll cell ultrastructure, gas exchange, chlorophyll and carotenoid content, and PSII in tobacco leaf were studied by simulating water deficit conditions via treatment with 25% PEG-6000 for 24 h. The results showed that under drought stress, the mesophyll cell structure and morphology were destroyed, photosynthesis and gas-exchange processes changed, photosynthetic pigment content decreased, and the electron transfer efficiency in PSII reduced. However, compared with the control treatment, under drought conditions, the addition of exogenous calcium could stabilize...

Photosynthesis and leaf development of cherry tomato seedlings under different LED-based blue and red photon flux ratios

X. Y. Liu, X. L. Jiao, T. T. Chang, S. R. Guo, Z. G. Xu

Photosynthetica 2018, 56(4):1212-1217 | DOI: 10.1007/s11099-018-0814-8  

We investigated the photosynthesis and leaf development of cherry tomato seedlings grown under five different combinations of red and blue light provided by light-emitting diodes (LEDs). Fresh biomass increased significantly under treatments with blue light percentages of 50, 60, and 75%, with 50% blue-light-grown seedlings accumulating significantly more dry mass. The 25% blue-light-grown seedlings were obviously weaker than those from the other LED treatments. An increase in net photosynthetic rate upon blue light exposure (25-60%) was associated with increases in leaf mass per unit leaf area, leaf area, leaf density, stomatal number, chloroplast...

Combined stresses of light and chilling on photosynthesis of Fraxinus mandschurica seedlings in northeastern China

X. F. Li, L. Jin, C. Y. Zhu, Y. J. Wen, Y. Wang

Photosynthetica 2018, 56(4):1218-1223 | DOI: 10.1007/s11099-018-0803-y  

The chilling and light stresses were experimentally created to explore photosynthesis of Fraxinus mandshurica seedlings in northeast China. Net photosynthetic rate, stomatal conductance, and transpiration rate decreased significantly with the decline of temperature and light. Significant interaction effects of light and chilling were observed on gas exchange of photosynthesis. The minimal fluorescence yield of the dark-adapted state (F₀) increased with increasing light and decreasing temperature. Both high and low light stresses induced the decreases of the maximal quantum yield of PSII photochemistry (F_v/F_m),...

Comparative photosynthetic attributes of emmer and modern wheats in response to water and nitrogen supply

M. Vaghar, P. Ehsanzadeh

Photosynthetica 2018, 56(4):1224-1234 | DOI: 10.1007/s11099-018-0825-5  

A field study was conducted with the aim to elucidate photosynthetic responses of five emmer hulled wheat (Triticum turgidum ssp. dicoccum) accessions to 30 (N-limited) and 100 kg(N) ha^-1 (N-sufficient) conditions at control and drought stress (irrigation after 30-40% and 60-70% depletion of available soil water, respectively). Chlorophyll (Chl) a and Chl b concentrations of the emmer wheats remained unchanged but net photosynthetic rate and dry mass increased and decreased, respectively, when received a sufficient amount of N. Smaller drought-induced decreases in Chl concentration, membrane stability index, and dry...

Zinc accumulation, photosynthetic gas exchange, and chlorophyll a fluorescence in Zn-stressed Miscanthus × giganteus plants

G. Andrejić, G. Gajić, M. Prica, Ž. Dželetović, T. Rakić

Photosynthetica 2018, 56(4):1249-1258 | DOI: 10.1007/s11099-018-0827-3  

Accumulation and distribution of zinc within Miscanthus × giganteus plants grown on elevated Zn concentrations and their photosynthetic performance were investigated. High concentrations of Zn in soils caused an increase of its concentrations in all plant organs. The bioconcentration factor, bioaccumulation factor, and translocation factor were lower than one indicating that M. × giganteus is an excluder plant species. Excessive Zn induced visible leaf damage, i.e. chlorosis and necrosis, only in the oldest leaves, pointing to Zn accumulation. Elevated amounts of Zn in leaves significantly lowered the photosynthetic...

Chilling-induced reduction of photosynthesis is mitigated by exposure to elevated CO₂ concentrations

C. Arena, L. Vitale

Photosynthetica 2018, 56(4):1259-1267 | DOI: 10.1007/s11099-018-0843-3  

This work aimed to evaluate if chilling stress may be mitigated by elevated CO₂ (EC) in Beta vulgaris L. plants. Photosynthetic rate was measured at 21% and 2% O₂ after a short-term exposure of 5 h at four different treatments: 360 μmol(CO₂) mol^-1/25°C (AC); 360 μmol(CO₂) mol^-1/4°C (AC+LT); 700 μmol(CO₂) mol^-1/25°C (EC); 700 μmol(CO₂) mol-1/4°C (EC+LT). Compared to AC+LT, EC+LT plants showed higher values of CO₂ fixation, photochemical activity, and Rubisco amount. These latter invest a higher portion of photosynthetic electron...

Reduction of photosynthetic apparatus plays a key role in survival of the microalga Haematococcus pluvialis (Chlorophyceae) at freezing temperatures

K. Chekanov, S. Vasilieva, A. Solovchenko, E. Lobakova

Photosynthetica 2018, 56(4):1268-1277 | DOI: 10.1007/s11099-018-0841-5  

The microalga Haematococcus pluvialis is a biotechnologically important microorganism producing a ketocarotenoid astaxanthin. Haematococcus exists either as metabolically active vegetative cells with a high chlorophyll content or astaxanthin-rich haematocysts (aplanospores). This microalga featuring outstanding tolerance to a wide range of adverse conditions is a highly suitable model for studies of freezing tolerance in phototrophs. The retention of H. pluvialis cell viability after freezing-thawing is ascribed to elevated antioxidant enzyme activity and high ketocarotenoid content. However, we report that only haematocysts characterized...

Quality of supplementary LED lighting effects on growth and photosynthesis of two different Lactuca recombinant inbred lines (RILs) grown in a tropical greenhouse

T. W. Choong, J. He, L. Qin, S. K. Lee

Photosynthetica 2018, 56(4):1278-1286 | DOI: 10.1007/s11099-018-0828-2  

LED lamps with various combinations of red (R) and blue (B) wavelengths were used to supplement sunlight for the growth of a heat-resistant (HR) and heat-sensitive (HS) recombinant inbred lines (RIL) of lettuce. The RB-LED ratios were 100R:0B (0B), 92R:8B (8B), 84R:16B (16B), and 76R:24B (24B) with an equal PPFD of 100 μmol m^-2 s^-1. The greatest leaf expansion rates were observed at 8B for both genotypes. All HR-RILs had similar values of growth parameters and specific leaf area (SLA). However, higher values of growth parameters were observed in HS-RIL with 0B, 8B, and 16B than that under 24B and sunlight. Furthermore, HS-RIL...

Chlorophyll fluorescence, yield and yield components of bread wheat affected by phosphate bio-fertilizer, zinc and boron under late-season heat stress

H. R. Eisvand, H. Kamaei, F. Nazarian

Photosynthetica 2018, 56(4):1287-1296 | DOI: 10.1007/s11099-018-0829-1  

We examined effects of late-season heat stress (L-SHS) on chlorophyll (Chl) fluorescence parameters and yield of bread wheat as well as roles of phosphate bio-fertilizer (PB-F) and Zn and B to compensate for the likely effects of heat stress. Factors were planting date (21 November and 5 January to coincide with grain filling to L-SHS) as the main factor, no inoculation (control) and inoculation of the seeds with PB-F as the sub-factor, and foliar application of water (control), Zn, B, and Zn + B as 3 L ha^-1 as sub-sub factor. Results revealed that L-SHS reduced maximal quantum yield of PSII photochemistry, effective quantum yield of PSII...

Role of alternative oxidase pathway in protection against drought-induced photoinhibition in pepper leaves

W. H. Hu, X. H. Yan, Y. He, X. L. Ye

Photosynthetica 2018, 56(4):1297-1303 | DOI: 10.1007/s11099-018-0837-1  

The aim of this study was to assess the impact of the mitochondrial alternative oxidase (AOX) pathway on energy metabolism in chloroplasts, and evaluate the importance of the AOX in alleviating drought-induced photoinhibition in pepper (Capsicum annuum L.). Inhibition of AOX pathway decreased photosynthesis and increased thermal energy dissipation in plants under normal conditions. It indicated that AOX pathway could influence chloroplast energy metabolism. Drought reduced carbon assimilation. Photoinhibition was caused by excess of absorbed light energy in spite of the increase of thermal energy dissipation and cyclic electron flow around PSI...

Changes in winter snow depth affects photosynthesis and physiological characteristics of biological soil crusts in the Tengger Desert

R. Hui, R. M. Zhao, L. C. Liu, Y. X. Li, H. T. Yang, Y. L. Wang, M. Xie, X. Q. Wang

Photosynthetica 2018, 56(4):1304-1312 | DOI: 10.1007/s11099-018-0838-0  

Water availability is a major limiting factor in desert ecosystems. However, a winter snowfall role in the growth of biological soil crusts is still less investigated. Here, four snow treatments were designed to evaluate the effects of snow depth on photosynthesis and physiological characteristics of biological soil crusts. Results showed that snow strongly affected the chlorophyll fluorescence properties. The increased snow depth led to increased contents of photosynthetic pigments and soluble proteins. However, all biological soil crusts also exhibited a decline in malondialdehyde and soluble sugar contents as snow increased. Results demonstrated...

Effects of foliar applications of nitric oxide and spermidine on chlorophyll fluorescence, photosynthesis and antioxidant enzyme activities of citrus seedlings under salinity stress

D. Khoshbakht, M. R. Asghari, M. Haghighi

Photosynthetica 2018, 56(4):1313-1325 | DOI: 10.1007/s11099-018-0839-z  

The effects of exogenous sodium nitroprusside (SNP), as nitric oxide donor, and spermidine (Spd) on growth and photosynthetic characteristics of Bakraii seedlings (Citrus reticulata × Citrus limetta) were studied under NaCl stress. In citrus plants, SNP- and Spd-induced growth improvement was found to be associated with reduced electrolyte leakage, malondialdehyde, hydrogen peroxide content, and leaf Na⁺ and Cl^- concentration. However, we found increased leaf Ca²⁺, Mg²⁺, and K⁺ concentrations, relative water content, chlorophyll fluorescence parameters, antioxidant enzyme activities,...

Coordinated variation between veins and stomata in cotton and its relationship with water-use efficiency under drought stress

Z. Y. Lei, J. M. Han, X. P. Yi, W. F. Zhang, Y. L. Zhang

Photosynthetica 2018, 56(4):1326-1335 | DOI: 10.1007/s11099-018-0847-z  

Drought stress causes changes in vein and stomatal density. The objectives of this study were to determine (1) if the changes in vein and stomatal density are coordinated in cotton (Gossypium hirsutum L.) and (2) how these changes affect water-use efficiency (WUE). The results showed significant positive correlations between vein density and stomatal density when cotton was grown under different degrees of drought stress. WUE was significantly positively correlated with the densities of both veins and stomata. Stomatal pore area and stomatal density on the abaxial leaf side, but not the adaxial side, were significantly correlated...

Soil Cu contamination destroys the photosynthetic systems and hampers the growth of green vegetables

M.-Z. Lin, M.-F. Jin

Photosynthetica 2018, 56(4):1336-1345 | DOI: 10.1007/s11099-018-0831-7  

Soil metal contamination leads to a decrease in a yield of crops and is a threat to human health. In the present study, the properties (i.e., photosynthetic pigments, gas-exchange parameters, chlorophyll fluorescence, biomass, leaf area, leaf mass per area) of three green vegetables (i.e., Brassica chinensis, Chrysanthemum coronarium, Brassica alboglabra) grown under various Cu treatments [0, 200, 400, and 600 mg(Cu) kg^-1] were measured and analysed. The results showed that soil Cu contamination resulted in the damage of photosynthetic pigments, negative effects on gas exchange, and hampered growth of all...

Cadmium stress in Dongying wild soybean seedlings: growth, Cd accumulation, and photosynthesis

L. Liu, Y. K. Shang, L. Li, Y. H. Chen, Z. Z. Qin, L. J. Zhou, M. Yuan, C. B. Ding, J. Liu, Y. Huang, R. W. Yang, Y. H. Zhou, J. Q. Liao

Photosynthetica 2018, 56(4):1346-1352 | DOI: 10.1007/s11099-018-0844-2  

In order to understand better Cd resistance in soybean, Dongying wild soybean treated with different Cd concentrations were evaluated. The biomass, chlorophyll (Chl) content, leaf color, Chl a fluorescence parameters, photosynthesis parameters, and Cd contents were determined. Our results showed that when Cd concentration was ≤ 2 kg m^-3, no significant decrease in biomass, photosynthetic parameters, and maximal photochemical efficiency of PSII was observed. This indicated that Dongying wild soybean resisted Cd toxic effects under such conditions. In addition, atomic absorption experiment results demonstrated that when Cd concentration...

Morphological and ecophysiological plasticity in dioecious plant Populus tomentosa under drought and alkaline stresses

Y. W. Lu, X. L. Miao, Q. Y. Song, S. M. Peng, B. L. Duan

Photosynthetica 2018, 56(4):1353-1364 | DOI: 10.1007/s11099-018-0846-0  

Morphological and ecophysiological traits showed by male and female Populus tomentosa Carr. trees were studied under various degrees of water and alkaline stresses. The results showed that different adaptations to drought and alkaline stresses were adopted by each gender; males possessed a much higher tolerance to both stresses compared to females. In contrast to females, the males exhibited a lower inhibition in total biomass, total leaf area, net photosynthetic rate, stomatal conductance, leaf carbon and nitrogen concentrations as well as water- and nitrogen-use efficiency in response to drought and alkaline stresses. Nevertheless, compared...

Viscosimetric analysis of the mechanism of ATP hydrolysis by pea chloroplast F₁-ATPase

A.N. Malyan

Photosynthetica 2018, 56(4):1365-1369 | DOI: 10.1007/s11099-018-0840-6  

Dependence of ATP hydrolysis kinetics by the chloroplast coupling factor (CF₁) on medium viscosity was studied at varying temperatures. For samples with oxidized and reduced CF₁ γ-subunit, this dependence was shown to be described by Cramers' relationship k ~ (η/η_o)-n, where k is the reaction rate constant, η/η_o is the medium/water viscosity ratio, and 0 < n < 1. Transition of the γ-subunit from its reduced to oxidized state was accompanied by increasing n value, which is indicative of increasing friction losses between certain enzyme sections...

Salicylic acid-induced photosynthetic adaptability of Zea mays L. to polyethylene glycol-simulated water deficit is associated with nitric oxide signaling

R. X. Shao, L. F. Xin, J. M. Guo, H. F. Zheng, J. Mao, X.P. Han, L. Jia, S. J. Jia, C. G. Du, R. Song, Q. H. Yang, R. W. Elmore

Photosynthetica 2018, 56(4):1370-1377 | DOI: 10.1007/s11099-018-0850-4  

Salicylic acid (SA) and nitric oxide (NO) form a new group of plant growth substances that cooperatively interact to promote plant growth and productivity. Water deficit (WD) stress is a major limiting factor for photosynthesis, which in turn limits crop yield. However, the mechanism of SA and NO in stimulating photosynthesis has not yet been elucidated. Therefore, in this study, we investigated the SA- and NO-mediated photosynthetic adaptability of maize seedlings to WD in terms of photosynthetic parameters, activities and mRNA levels of CO₂ assimilation enzymes. Our results showed that SA alleviated the WD-induced reduction of photosynthetic...

Foliar exposure of grapevine (Vitis vinifera L.) to TiO₂ nanoparticles under field conditions: Photosynthetic response and flavonol profile

P. Teszlák, M. Kocsis, A. Scarpellini, G. Jakab, L. Kőrösi

Photosynthetica 2018, 56(4):1378-1386 | DOI: 10.1007/s11099-018-0832-6  

In the past decade, utilization of nanostructured materials has increased intensively in a wide range of applications. Titanium dioxide nanoparticles (TiO₂ NPs), for instance, can be applied for the inactivation of various pathogens through photo-induced generation of reactive oxygen species. Although TiO₂ NPs with high antimicrobial activity are of great importance, in practice, their phytotoxic effects have not yet been fully clarified. In this study, we investigated the potential phytotoxicity of TiO₂ NPs on grapevine (Vitis vinifera L.) under field conditions. After foliar exposure, two particularly stress-sensitive...

Leaf gas exchange and grain yield of common bean exposed to spermidine under water stress

S. Torabian, M. R. Shakiba, A. Dabbagh Mohammadi Nasab, M. Toorchi

Photosynthetica 2018, 56(4):1387-1397 | DOI: 10.1007/s11099-018-0834-4  

Three prevalent aliphatic polyamines (PAs) include putrescine, spermidine, and spermine; they are low-molecular-mass polycations involved in many physiological processes in plants, especially, under stressful conditions. In this experiment, three bean (Phaseolus vulgaris L.) genotypes were subjected to well-watered conditions and two moderate and severe water-stressed conditions with and without spermidine foliar application. Water stress reduced leaf relative water content (RWC), chlorophyll contents, stomatal conductance (gs), intercellular CO₂ concentration (C_i), transpiration rate, maximal quantum yield...

Seasonal variation in photosynthesis performance of cassava at two different growth stages under irrigated and rain-fed conditions in a tropical savanna climate

K. Vongcharoen, S. Santanoo, P. Banterng, S. Jogloy, N. Vorasoot, P. Theerakulpisut

Photosynthetica 2018, 56(4):1398-1413 | DOI: 10.1007/s11099-018-0849-x  

Seasonal variations in photosynthesis of cassava cv. Rayong 9 (RY9) under irrigated and rain-fed conditions were evaluated at the age of three and six months after planting (MAP). Photosynthetic light-response (P_N/I) curves revealed that cassava leaves attained the highest maximum net photosynthetic rates (P_Nmax) in the rainy season, followed by the hot one, while the lowest P_Nmax was found in the cool season. Photosynthetic potential of the 3-month-old plants was mostly higher than that of the 6-month-old plants, and the seasonal variation in photosynthetic capacity was also more apparent...

Leaf gas exchange, phosphorus uptake, growth and yield responses of cotton cultivars to different phosphorus rates

J. Wang, Y. Chen, P. Wang, Y. S. Li, G. Wang, P. Liu, A. Khan

Photosynthetica 2018, 56(4):1414-1421 | DOI: 10.1007/s11099-018-0845-1  

Growth and physiological responses of cotton (Gossypium hirsutum L.) cultivars with different phosphorus (P) efficiencies under variable P environment are poorly known. Therefore, this study explored effects of normal P [P⁺, 70 kg(P₂O₅) ha^-1] and without P (P^-, 0 kg ha^-1) on yield, growth, and physiology of different P-efficient cultivars [low-efficient Xinluzao 13 (L1) and Xinluzao 26 (L₂); medium-efficient Xinluzao 10 (M₁) and Xinluzao 24 (M₂); high-efficient Zhongmiansuo 42 (H₁) and Xinluzao19 (H₂)]. Cotton growth and yield...

Bioaccumulation and photosynthetic activity response of sweet sorghum seedling (Sorghum bicolor L. Moench) to cadmium stress

Z. C. Xue, J. H. Li, D. S. Li, S. Z. Li, C. D. Jiang, L. A. Liu, S. Y. Wang, W. J. Kang

Photosynthetica 2018, 56(4):1422-1428 | DOI: 10.1007/s11099-018-0835-3  

A hydroponic experiment was conducted to investigate bioaccumulation and photosynthetic activity response to Cd in sweet sorghum seedlings. The seedlings were treated with 0, 50, and 100 μM Cd for 15 d. Our results showed that morphological characteristics of sweet sorghum were significantly affected by Cd treatments. The Cd concentrations in roots and shoots increased with increasing Cd concentrations in the nutrition solution; higher Cd accumulation was observed in the roots. Meanwhile, the photosynthetic activity decreased significantly and a shape of chlorophyll (Chl) a fluorescence transient in leaves was altered by Cd treatments. The...

Effects of leaf-to-fruit ratio on chlorophyll fluorescence parameters of walnut (Juglans regia L.) leaves

C. F. Zhang, C. D. Pan, H. Chen

Photosynthetica 2018, 56(4):1429-1436 | DOI: 10.1007/s11099-018-0842-4  

In this study, we investigated maximal quantum yield of PSII photochemistry(F_v/F_m),effective quantum yield of PSII photochemistry (Φ_PSII), and nonphotochemical quenching (NPQ) of walnut (Juglans regia 'Xinxin2') leaves with different leaf-to-fruit ratios (LFRs). The results indicated that the increasing LFR increased the values of F_v/F_m, Φ_PSII, and NPQ in leaves on the girdled shoot with one and two leaves, and decreased the values of F_v/F_m and Φ_PSII in leaves on the girdled shoot with five leaves, whereas had no effect on the chlorophyll...

Responses of photosynthesis, dry mass and carbon isotope discrimination in winter wheat to different irrigation depths

L. J. Zheng, J. J. Ma, X. H. Sun, X. H. Guo, J. Jiang, R. Ren, X. L. Zhang

Photosynthetica 2018, 56(4):1437-1446 | DOI: 10.1007/s11099-018-0833-5  

In order to test the effects of irrigation depth on winter wheat photosynthesis, four treatments were applied in a field experiment using PVC growth tubes (identical amounts of water were applied on the land surface, and at 60, 75, and 90% of the depth for the winter wheat root distribution, denoted as D0, D60, D75, and D90, respectively). Compared to the surface irrigation treatment D0, the leaf area index, chlorophyll content, net photosynthetic rate, transpiration rate, stomatal conductance, and intercellular CO₂ concentration increased with irrigation depths. The values of these indicators obtained by the underground irrigation treatment...

A method of a bicolor fast-Fourier pulse-amplitude modulation chlorophyll fluorometry

V. Lysenko, D. Lazár, T. Varduny

Photosynthetica 2018, 56(4):1447-1452 | DOI: 10.1007/s11099-018-0848-y  

A simple method of a bicolor (multicolor), fast-Fourier, PAM chlorophyll fluorometry has been developed to obtain fluorescence induction curves. Quantum yields of PSII photochemistry were determined with blue and red simultaneously applied pulsed measuring lights for three subsequent 20-min periods of dark-, light-adaptation under actinic light and dark recovery. Measuring lights were cross-combined with blue and red actinic lights and saturation pulses. Coefficients of chromatic divergence were calculated as a ratio of the quantum yields obtained by red measuring light to that obtained by blue measuring light. Adaptation of Ficus benjamina...

Effects of endogenous ascorbic acid on resistance to high-temperature stress in excised rice leaves

Q.L. Zhang, Y.X. Wei, C.L. Peng

Photosynthetica 2018, 56(4):1453-1458 | DOI: 10.1007/s11099-018-0836-2  

Ascorbic acid (Asc) is a major plant antioxidant. L-galactono-1,4-lactone dehydrogenase (GLDH) is an enzyme that catalyzes the last step of Asc biosynthesis in higher plants. Effects of endogenous Asc on resistance to high-temperature stress were studied by using GLDH-overexpressed (GO-2) and GLDH-suppressed transgenic rice (GI-2) as experimental materials. After high-temperature treatment, the maximal quantum yield of PSII was significantly lower in GI-2, and higher in GO-2 compared to wild type rice. The content of reactive oxygen species (ROS) was the highest in GI-2. The higher Asc content resulted in lower lipid peroxidation in GO-2. The contents...

Hydrogen peroxide in regulation of plant metabolism: Signalling and its effect under abiotic stress

T.A. Khan, M. Yusuf, Q. Fariduddin

Photosynthetica 2018, 56(4):1237-1248 | DOI: 10.1007/s11099-018-0830-8  

In plants, hydrogen peroxide (H₂O₂) acts as a signalling molecule that facilitates various biochemical and physiological processes. H₂O₂ is a versatile molecule, involved in several cellular processes both under stress and stress-free conditions. In regulating plant metabolism under stress conditions, exogenous application of H₂O₂ also plays a pivotal role which is manifested in improved growth, photosynthetic capacity, and antioxidant protection. Abiotic stress is an inevitable environmental factor that extensively affects and reduces growth, quality, yield, and productivity of plants....

Our gratitude and congratulations to our guest editor Julian Eaton-Rye and thanks to all the 167 contributors to the special issue honoring professor Govindjee

Győző Garab

Photosynthetica 2018, 56(4):1235-1236 | DOI: 10.1007/s11099-018-0826-4