Effects of Ca²⁺ and polyethylene glycol on the chlorophyll fluorescence parameters of transgenic OsCaS rice (Oryza sativa L.)

R. Wei, Y. Liu, Y. Sui, M. Xu, S. Liu, X. Zhao

Photosynthetica 2015, 53(3):336-341 | DOI: 10.1007/s11099-015-0107-4  

Ca²⁺ is an important factor mediating many biotic and abiotic stress responses in plants. In this study, we measured the chlorophyll (Chl) fluorescence of transgenic rice with increased or decreased expression of a calcium-sensing receptor (OsCaS) gene during water deficit caused by polyethylene glycol to prove our hypothesis that increased Ca²⁺ in combination with increased OsCaS could enhance the drought resistance of transgenic rice. Transcript abundance (evaluated by RT-PCR) was significantly lower in OsCaS antisense line 766 (AS766) than that in the wild type, while the overexpression line 777 (O777)...

Simple and accurate allometric model for leaf area estimation in Vitis vinifera L. genotypes

D. Buttaro, Y. Rouphael, C. M. Rivera, G. Colla, M. Gonnella

Photosynthetica 2015, 53(3):342-348 | DOI: 10.1007/s11099-015-0117-2  

The aim of the present experiment was to evaluate the currently used allometric models for Vitis vinifera L., as well as to develop a simple and accurate model using linear measurements [leaf length (L) and leaf width (W)], for estimating the individual leaf area (LA) of nine grapevine genotypes. For model construction, a total of 1,630 leaves coming from eight genotypes in 2010 was sampled during different leaf developmental stages and encompassed the full spectrum of leaf sizes. The model with single measurement of L could be considered an interesting option because it requires measurement of only one variable, but at the expense of accuracy....

Photosynthetic responses of Jatropha curcas to spider mite injury

M. H. Hsu, C. C. Chen, K. H. Lin, M. Y. Huang, C. M. Yang, W. D. Huang

Photosynthetica 2015, 53(3):349-355 | DOI: 10.1007/s11099-015-0132-3  

The spider mite Tetranychus urticae Koch is emerging as a major problem in Jatropha curcas cultivation. The goal of this study was to investigate the photosynthetic responses of Jatropha to spider mite infestation. Leaf CO₂ assimilation rate, stomatal conductance, transpiration, intracellular CO₂ concentration, and instantaneous carboxylation efficiency significantly decreased in mite-infested leaves compared with controls. Lower water content and specific leaf area of the mite-infested leaves were positively related to symptoms of wrinkling and curling. Leaf electrolyte leakage remained unchanged in the mite-infested...

Disentangling long- and short-term changes in perennial organ functions in seasonal environments: A model of foliar chlorophyll and nitrogen in saplings of four evergreen broad-leaved trees

D. Mizusaki, K. Umeki, T. Honjo

Photosynthetica 2015, 53(3):356-368 | DOI: 10.1007/s11099-015-0145-y  

Perennial organ functions of trees living in seasonal environments exhibit temporal changes that can be classified as long-term interannual changes and seasonal fluctuations within single years. However, few studies have separately quantified these changes from longitudinal measurement data or analyzed the relationships between them. We developed a hierarchical Bayesian statistical model consisting of three parts: a long-term interannual change expressed by consecutive annual linear trends, seasonal fluctuations with 26 values for two-week periods in a year, and a random effect for repeated measurements. The model can extract long-term interannual...

Structural and functional changes in the photosynthetic apparatus of Chlamydomonas reinhardtii during nitrogen deprivation and replenishment

É. Preininger, A. Kósa, Z. S. Lőrincz, P. Nyitrai, J. Simon, B. Böddi, Á. Keresztes, I. Gyurján

Photosynthetica 2015, 53(3):369-377 | DOI: 10.1007/s11099-015-0129-y  

Nitrogen is an essential factor for normal plant and algal development. As a component of nucleic acids, proteins, and chlorophyll (Chl) molecules, it has a crucial role in the organization of a functioning photosynthetic apparatus. Our aim was to study the effects of nitrogen starvation in cultures of the unicellular green alga, Chlamydomonas reinhardtii, maintained on nitrogen-free, and then on nitrogen-containing medium. During the three-week-long degreening process, considerable changes were observed in the Chl content, the ratio of Chl-protein complexes, and photosynthetic activity of the cultures as well as in the ultrastructure of single...

Differences in transport of photosynthates between high-and low-yielding Ipomoea batatas L. varieties

H. J. Liu, S. S. Chai, C. Y. Shi, C. J. Wang, G. B. Ren, Y. Jiang, C. C. Si

Photosynthetica 2015, 53(3):378-388 | DOI: 10.1007/s11099-015-0121-6  

Previous studies have focused mainly on the accumulation of photosynthates and less on their distribution in sweet potato (Ipomoea batatas L.). In addition, the effect of photosynthate accumulation in root tubers on photosynthate distribution was not considered. Thus, a field experiment was carried out from May to October (2011 and 2012) to clarify the differences in photosynthate transport between high- and low-yielding sweet potato. This study mainly focused on the photosynthetic capacities of leaves, photosynthate distribution, and characteristics of photosynthate accumulation in root tubers. Results showed the high-yielding varieties displayed...

Daily temperature drop prevents inhibition of photosynthesis in tomato plants under continuous light

E. N. Ikkonen, T. G. Shibaeva, E. Rosenqvist, C. O. Ottosen

Photosynthetica 2015, 53(3):389-394 | DOI: 10.1007/s11099-015-0115-4  

The negative effects of continuous light (CL) seen in tomato plants are often claimed to be linked to effects of offsetting the diurnal rhythm. In this study we tested whether a short-term daily temperature drop prevents the decreased photosynthetic performance seen in tomato plants grown under CL. Tomato (Lycopersicon esculentum Mill.) plantlets were grown at constant temperature of 26°C under 16-h day (16D) or 24-h day (24D) at 150 μmol m^-2 s^-1 PPFD. Some 24D plants were treated daily by 2 h temperature drop from 26 to 10°C (24D+DROP). Physiological disorder, such as severe leaf chlorosis, a large decrease in net photosynthetic...

Responses of two endemic species of Hippophae at the Qinghai-Tibet Plateau to elevated CO₂ concentration

F. Ma, T. T. Xu, M. F. Ji, C. M. Zhao

Photosynthetica 2015, 53(3):395-402 | DOI: 10.1007/s11099-015-0125-2  

The responses of photosynthesis and growth to increasing CO₂ concentration ([CO₂]) were investigated in Hippophae gyantsensis and H. rhamnoides subsp. yunnanensis, which are endemic at the Qinghai-Tibet Plateau and phylogenetically related, but distributed parapatrically in divergent regions. Seedlings of the two species were grown at ambient [AC; 360 μmol(CO₂) mol^-1] and elevated [EC; 720 μmol(CO₂) mol^-1] [CO₂] in growth chambers. The responses to EC were significantly different between the two species. EC induced an increase in photosynthesis,...

Effect of high light intensity on photoinhibition, oxyradicals and artemisinin content in Artemisia annua L.

M. E. Poulson, T. Thai

Photosynthetica 2015, 53(3):403-409 | DOI: 10.1007/s11099-015-0130-5  

Artemisia annua L. produces a compound called artemisinin that is a potent anti-malarial compound. However concentration of artemisinin within the plant is typically low (less than 0.8% of dry mass) and currently supply of the drug by the plant does not meet world demand. This investigation was carried out to determine whether high intensity light treatment would increase production of artemisinin in leaves of A. annua. Photoinhibition (14%) was induced in leaves of A. annua when they were subjected to 6 h of high-intensity light [2,000 μmol(photon) m^-2 s^-1]. Maximum photochemical efficiency of PSII showed...

Influence of foliar-applied salicylic acid on growth, gas-exchange characteristics, and chlorophyll fluorescence in citrus under saline conditions

D. Khoshbakht, M. R. Asgharei

Photosynthetica 2015, 53(3):410-418 | DOI: 10.1007/s11099-015-0109-2  

Salicylic acid (SA) is a common, plant-produced signal molecule that is responsible for inducing tolerance to a number of biotic and abiotic stresses. Our experiment was therefore conducted to test whether the application of SA at various concentrations (0, 0.10, 0.50, and 1.00 mM) as a foliar spray would protect citrus seedlings (Valencia orange/Bakraii) subjected to salt stress (0, 25, 50, and 75 mM NaCl). Growth parameters, leaf chlorophyll (Chl) content, relative water content (RWC), maximal quantum yield of PSII photochemistry (F_v/F_m), and gas-exchange variables were negatively affected by salinity. In addition, leaf electrolyte...

Response of invasive Chromolaena odorata and two coexisting weeds to contrasting irradiance and nitrogen

G. M. Quan, D. J. Mao, J. E. Zhang, J. F. Xie, H. Q. Xu, M. An

Photosynthetica 2015, 53(3):419-429 | DOI: 10.1007/s11099-015-0137-y  

Chromolaena odorata is a widespread exotic weed in southern China and other regions of the world. To better understand its invasive strategies, we compared leaf pigment contents and gas-exchange traits of the invader with its two coexisting species (native Urena lobata and invasive Bidens pilosa) under combined conditions of irradiance (full, medium, and low) and nitrogen (full, medium, and low) supplies. The chlorophyll (Chl) a+b content of U. lobata was the highest and the Chl a/b ratio of C. odorata was the lowest among the three weed species. In most treatments, leaf pigment, light-saturated...

The effects of the phenol concentrations on photosynthetic parameters of Salix babylonica L.

H. Li, G. C. Zhang, H. C. Xie, K. Li, S. Y. Zhang

Photosynthetica 2015, 53(3):430-435 | DOI: 10.1007/s11099-015-0135-0  

As a common waterfront and wet environment tree species, Salix babylonica shows a great potential for restoration of contaminated water or soil environments, such as phenol-polluted water. However, studies on such remediation effects have not been carried out yet. The objective of this study was to investigate the effects of phenols on photosynthesis of S. babylonica. Photosynthetic and chlorophyll fluorescence parameters of S. babylonica cuttings were determined in hydroponic experiment, where six phenol concentrations was used (0, 50, 100, 200, 400, and 800 mg L^-1). Phenol presence inhibited photosynthesis of S....

Overexpression of maize phosphoenolpyruvate carboxylase improves drought tolerance in rice by stabilization the function and structure of thylakoid membrane

W. J. Shen, G. X. Chen, J. G. Xu, Y. Jiang, L. Liu, Z. P. Gao, J. Ma, X. Chen, T. H. Chen, C. F. Lv

Photosynthetica 2015, 53(3):436-446 | DOI: 10.1007/s11099-015-0111-8  

Drought impacts severely crop photosynthesis and productivity. Development of transgenic rice overexpressing maize phosphoenolpyruvate carboxylase (PEPC) is a promising strategy for improving crop production under drought stress. However, the molecular mechanisms of protection from PEPC are not yet clear. The objective of this study was: first, to characterize the response of individual photosynthetic components to drought stress; second, to study the physiological and molecular mechanisms underlying the drought tolerance of transgenic rice (cv. Kitaake) over-expressing maize PEPC. Our results showed that PEPC overexpressing improved...

Positive correlation between potassium uptake and salt tolerance in wheat

D. Cheng, G. Wu, Y. Zheng

Photosynthetica 2015, 53(3):447-454 | DOI: 10.1007/s11099-015-0124-3  

The aim of our study was to answer whether any positive correlation exists between K⁺ uptake and salt tolerance in wheat. We carried out a sand-culture experiment with salt-tolerant, DK961 (ST), and salt-sensitive, JN17 (SS), wheat cultivars, where photosynthesis, the K⁺/Na⁺ ratio, growth, and the biomass yield were examined. The seeds were exposed for four weeks to six NaCl concentrations (50, 100, 150, 200, 250, and 300 mM), which were embodied in the Hoagland solution. Salinity-induced decrease of K⁺ or increase in the Na⁺ content was much smaller in ST than that in SS. The reductions in the...

Responses of gas exchange, chlorophyll synthesis and ROS-scavenging systems to salinity stress in two ramie (Boehmeria nivea L.) cultivars

C. J. Huang, G. Wei, Y. C. Jie, J. J. Xu, S. Y. Zhao, L. C. Wang, S. A. Anjum

Photosynthetica 2015, 53(3):455-463 | DOI: 10.1007/s11099-015-0127-0  

Ramie (Boehmeria nivea L.) is an important crop that serves as fine fiber material, high protein feedstuff, and valuable herbal medicine in China. However, increasing salinity in soil limits the productivity. We investigated in a greenhouse experiment responses to salinity in two ramie cultivars, Chuanzhu-12 (salt-tolerant cultivar, ST) and Xiangzhu-2 (salt-sensitive cultivar, SS), to elucidate the salt tolerance mechanism of this species. Salinity stress substantially reduced both chlorophyll and carotenoid contents. In addition, net photosynthesis, transpiration rate, stomatal conductance, intercellular CO₂ concentration, and the...

Photosynthetic capacity and intrinsic water-use efficiency of Rhizophora mangle at its southernmost western Atlantic range

M. L. Gomes Soares, M. M. Pereira Tognella, E. Cuevas, E. Medina

Photosynthetica 2015, 53(3):464-470 | DOI: 10.1007/s11099-015-0119-0  

The southernmost presence of Rhizophora mangle in the western Atlantic coast occurs in coastal wetlands between 27 and 28°S in the State of Santa Catarina, Brazil. We selected mangrove communities at the estuary of the River Tavares, Florianopolis, and the Sonho Beach, Palhosa, for measurement of photosynthetic performance and intrinsic water-use efficiency of R. mangle and coexisting individuals of Avicennia schaueriana and Laguncularia racemosa, during the spring season. We used gas-exchange techniques and isotopic signatures of C and N to estimate instantaneous water-use and carboxylation efficiency (CE), long-term water-use...

Differential blockage of photosynthetic electron flow in young and mature leaves of Arabidopsis thaliana by exogenous proline

I. Sperdouli, M. Moustakas

Photosynthetica 2015, 53(3):471-477 | DOI: 10.1007/s11099-015-0116-3  

Responses of the photosynthetic electron transport system of chloroplasts to exogenous proline application were evaluated in young and mature leaves of Arabidopsis thaliana plants under optimal growth conditions. Exogenous proline application (10 mM) during the 4^th week of growth increased proline accumulation in young leaves more than in mature leaves, and possibly due to its degradation producing NADPH, decreased significantly the ratio of NADP⁺/NADPH in both leaf types compared with controls (without proline). However, the ratio of NADP⁺/NADPH remained significantly higher in the young leaves, suggesting lower...

Chloroplast and photosystems: Impact of cadmium and iron deficiency

H. Bashir, M. I. Qureshi, M. M. Ibrahim, M. Iqbal

Photosynthetica 2015, 53(3):321-335 | DOI: 10.1007/s11099-015-0152-z  

Chloroplasts utilize photons from solar radiation to synthesize energy-rich molecules of ATPs and NADPHs, which are further used in active cellular processes. Multiprotein complexes (MPCs), including photosystems (PSII and PSI), and the cellular architecture responsible for generation of the proton motive force and the subsequent photophosphorylation, mediate the task of ATP and NADPH synthesis. Both photosystems and other multiprotein assemblies are embedded in thylakoid membranes. Advances in techniques used to study structural biology, biophysics, and comparative genomics and proteomics have enabled us to gain insights of structure, function, and...

Colin A. Wraight

Govindjee, R. C. Prince, D. R. Ort

Photosynthetica 2015, 53(3):478-480 | DOI: 10.1007/s11099-015-0154-x