Chlorophyll a fluorescence as a tool for a study of the Potato virus Y effects on photosynthesis of nontransgenic and transgenic Pssu-ipt tobacco

P. Spoustová, H. Synková, R. Valcke, N. Čeřovská

Photosynthetica 2013, 51(2):191-201 | DOI: 10.1007/s11099-013-0023-4

The effect of Potato virus Y ^NTN (PVY) infection upon photosynthesis was analysed in transgenic Pssu-ipt tobacco overproducing endogenous cytokinins in comparison with control, nontransgenic Nicotiana tabacum plants. The course of the infection from the early to the late stage was monitored by measuring of photosynthetic gas exchange and fast chlorophyll (Chl) a fluorescence induction kinetics. Leaf photosynthesis was also analysed using Chl fluorescence imaging (Chl-FI). From the different fluorescence parameters obtained using Chl-FI, the nonphotochemical quenching (NPQ) proved to be the most useful parameter...

Combined effects of light and temperature on growth, photosynthesis, and pigment content in the mat-forming cyanobacterium Geitlerinema amphibium

S. Jodłowska, A. Latała

Photosynthetica 2013, 51(2):202-214 | DOI: 10.1007/s11099-013-0019-0

Geitlerinema amphibium (BA-13), mat-forming cyanobacterium from the southern Baltic Sea, was grown at three irradiances [5, 65, and 125 μmol(photon) m^-2 s^-1] and three temperatures (15, 22.5, and 30°C). To determine the effect of the investigated factors and their interaction on culture concentration, pigment content, and photosynthetic parameters of cyanobacterium, factorial experiments and two-way analysis of variance (ANOVA) were carried out. Both chlorophyll (Chl) a and phycobilins (PB) were influenced by the irradiance and temperature, but stronger effect was noted in the case of the former one. Chl...

A newly developed SGB buffer greatly enhances energy transfer efficiency from phycobilisomes to photosystem II in cyanobacteria in vitro

L. P. Chen, Q. X. Wang, W. M. Ma

Photosynthetica 2013, 51(2):215-220 | DOI: 10.1007/s11099-013-0018-1

The transfer of light energy from phycobilisomes (PBS) to photosystem II (PSII) reaction centers is vital for photosynthesis in cyanobacteria and red algae. To investigate the relationship between PBS and PSII and to optimize the energy transfer efficiency from PBS to PSII, isolation of the PBS-PSII supercomplex is necessary. SPC (sucrose/phosphate/citrate) is a conventional buffer for isolating PBS-PSII supercomplex in cyanobacteria. However, the energy transfer occurring in the supercomplex is poor. Here, we developed a new buffer named SGB by adding 1M glycinebetaine and additional sucrose to SPC buffer. Compared to SPC, the newly developed SGB...

Excitation kinetics of chlorophyll fluorescence during light-induced greening and establishment of photosynthetic activity of barley seedlings

C. Buschmann, S. Konanz, M. Zhou, S. Lenk, L. Kocsányi, A. Barócsi

Photosynthetica 2013, 51(2):221-230 | DOI: 10.1007/s11099-013-0017-2

Excitation kinetics based on feedback regulation of chlorophyll (Chl) fluorescence of leaves measured with the chlorophyll fluorometer, FluoroMeter Modul (FMM), are presented. These kinetics showed the variation of excitation light (laser power, LP) regulated by the feedback mechanism of the FMM, an intelligent Chl fluorometer with embedded computer, which maintains the fluorescence response constant during the 300-s transient between the dark- and lightadapted state of photosynthesis. The excitation kinetics exhibited a rise of LP with different time constants and fluctuations leading to a type of steady state. The variation of excitation kinetics...

Photosynthesis and root characteristics of rice (Oryza sativa L.) in floating culture

H. X. Wu, Y. Z. Ma, J. P. Xiao, Z. H. Zhang, Z. H. Shi

Photosynthetica 2013, 51(2):231-237 | DOI: 10.1007/s11099-013-0015-4

To address the issue of water eutrophication and to use water more effectively, we conducted experiments on rice (Oryza sativa L.) grown in floating culture. From 2009 to 2011, we compared the photosynthesis and root characteristics of the rice, hybrid line Zhuliangyou 02, grown under a conventional tillage and in a floating culture in Huaihua, the home of hybrid rice. Rice in the floating culture showed a higher net photosynthetic rate and stomatal conductance than that under the conventional tillage. The activities of phosphoenolpyruvate carboxylase and NADP-malic enzyme were 32 and 28% higher, respectively, in rice in the floating...

Enhancement of low-temperature tolerance in transgenic tomato plants overexpressing Lefad7 through regulation of trienoic fatty acids

X. Y. Liu, Y. B. Teng, B. Li, Q. W. Meng

Photosynthetica 2013, 51(2):238-244 | DOI: 10.1007/s11099-013-0014-5

We studied how tomato (Lycopersicon esculentum Mill.) chloroplast omega-3 fatty acid desaturase gene (Lefad7) overexpression enhanced low-temperature (LT) tolerance in transgenic tomato plants. In these plants, the content of linolenic acid (18:3) markedly increased and, correspondingly, the content of linoleic acid (18:2) decreased. Similar changes were found after 6 h under LT (4°C) treatment. Under LT stress, wild type (WT) tomato plants showed a much greater increase in relative electrolyte leakage and malondialdehyde (MDA) contents compared with transgenic plants. Transgenic plants exhibited higher activities of antioxidative enzymes...

Ecophysiological response in leaves of Caragana microphylla to different soil phosphorus levels

T. T. Zhao, N. X. Zhao, Y. B. Gao

Photosynthetica 2013, 51(2):245-251 | DOI: 10.1007/s11099-013-0016-3

Phosphorus (P) is one of the limiting mineral nutrient elements in the typical steppe of Inner Mongolia, China. In order to find out the adaptive strategy of Caragana microphylla to low soil P status, we grew plants in P-deficient soil in April 2009 and gave a gradient of P addition ranging from 0 to 60 mg(P) kg^-1(soil) from May 2010. Leaf traits were measured in September 2010. Both leaf growth and light-saturated photosynthetic rate (P _max) were similar among different groups. Leaf nitrogen (N):P ratio indicated that the growth of C. microphylla was not P-limited in most of the Inner Mongolia typical steppe,...

Diurnal changes in photosynthesis and antioxidants of Angelica sinensis as influenced by cropping systems

X. H. Zhang, D. Y. Lang, E. H. Zhang, C. C. Bai, H. Z. Wang

Photosynthetica 2013, 51(2):252-258 | DOI: 10.1007/s11099-013-0013-6

Diurnal dynamics of photosynthetic character of Angelica sinensis, as well as effect of continuous cropping on leaf photosynthetic character, antioxidant enzyme activity and growth of A. sinensis were investigated under field condition. The results showed that the diurnal net photosynthetic rate of A. sinensis in sunny day exhibited a double-peak pattern, and the peaks occurred at 9:45 and 16:45 h, respectively. There was a significant midday depression with A. sinensis, which was caused principally by stomatal factors such as stomatal conductance. The results also showed that net photosynthetic rate (P _N),...

Photosynthetic performance of Anabaena variabilis PCC 7937 under simulated solar radiation

S. P. Singh, R. P. Rastogi, R. P. Sinha, D. P. Häder

Photosynthetica 2013, 51(2):259-266 | DOI: 10.1007/s11099-013-0012-7

In vivo chlorophyll fluorescence analysis reflecting the photosystem II functionality was investigated in the cyanobacterium Anabaena variabilis PCC 7937 under simulated solar radiation in a combination with various cut-off filters (WG 280, WG 295, WG 305, WG 320, WG 335, WG 345, and GG 400) to assess the effects of photosynthetically active radiation (PAR), ultraviolet-A (UV-A), and ultraviolet-B (UV-B) radiations on photosynthesis. The photosynthetic activity (PA) was severely inhibited immediately after 10 min of exposure to high PAR, UV-A, and UV-B radiations compared with low PAR grown control samples. After 1 h of exposure, PA of...

Responses to ozone on Populus "Oxford" clone in an open top chamber experiment assessed before sunrise and in full sunlight

R. Desotgiu, M. Pollastrini, C. Cascio, G. Gerosa, R. Marzuoli, F. Bussotti

Photosynthetica 2013, 51(2):267-280 | DOI: 10.1007/s11099-012-0074-y

The effects of ambient levels of ozone and summer drought were assessed on a poplar clone (Populus maximowiczii Henry X P. × berolinensis Dippel - Oxford clone) in an open top chamber experiment carried out at the Curno facilities (Northern Italy). Chlorophyll (Chl) a fluorescence parameters (from both modulated and direct fluorescence) were assessed at different hours of the day (predawn, morning, midday, afternoon, and evening), from June to August 2008. This paper compares the results from predawn (PD, before sunrise) and afternoon (AN, in full sunlight) measurements, in order to evaluate the role of high sunlight as...

Photosynthetic parameters of two invasive tree species of the Brazilian Pantanal in response to seasonal flooding

H. J. Dalmagro, F. A. de Lobo, G. L. Vourlitis, Â. C. Dalmolin, M. Z. Antunes Jr., C. E. R. Ortíz, J. de S. Nogueira

Photosynthetica 2013, 51(2):281-294 | DOI: 10.1007/s11099-013-0024-3

The Pantanal is the largest wetland in the world with extremely high plant and animal diversity, but large areas have been invaded by Vochysia divergens Pohl (Vochysiaceae), a tree that is native to the Amazon Basin, and Curatella americana L. (Dilleniaceae), a tree that is native to the Brazilian savanna (cerrado). V. divergens is reportedly floodadapted, thus its ability to invade the Pantanal may not be surprising, but the invasion of C. americana is counterintuitive, because this species is adapted to the well-drained soils of the cerrado. Thus, we were interested in comparing the photosynthetic capacity, in terms of...

Variations in leaf respiration across different seasons for Mediterranean evergreen species

R. Catoni, L. Varone, L. Gratani

Photosynthetica 2013, 51(2):295-304 | DOI: 10.1007/s11099-013-0026-1

Leaf respiration (R _L) of evergreen species co-occurring in the Mediterranean maquis developing along the Latium coast was analyzed. The results on the whole showed that the considered evergreen species had the same R _L trend during the year, with the lowest rates [0.83 ± 0.43 μmol(CO₂) m^-2 s^-1, mean value of the considered species] in winter, in response to low air temperatures. Higher R _L were reached in spring [2.44 ± 1.00 μmol(CO₂) m^-2 s^-1, mean value] during the favorable period, and in summer [3.17 ±...

Isolation and characterization of two genes of the early light-induced proteins of Camellia sinensis

X. W. Li, H. J. Liu, S. X. Xie, H. Y. Yuan

Photosynthetica 2013, 51(2):305-311 | DOI: 10.1007/s11099-013-0025-2

Early light-induced proteins (ELIPs) are nuclear-encoded thylakoid proteins. In the present research, two full-length cDNAs (741 and 815 bp), encoding ELIPs (190 and 175 aa) and their genomic sequences, were isolated from tea leaves, and named CsELIP1 and CsELIP2, respectively. Both the deduced CsELIPs contain a chloroplast transit peptide in the N-terminus and a chlorophyll a/b binding protein motif with three transmembrane helices in the C-terminus. The genomic sequences of the two CsELIPs conform to the three-exon pattern of ELIP genomic sequences of other plant species. However, the identities between two...

Photosynthesis under stressful environments: An overview

M. Ashraf, P. J. C. Harris

Photosynthetica 2013, 51(2):163-190 | DOI: 10.1007/s11099-013-0021-6

Stressful environments such as salinity, drought, and high temperature (heat) cause alterations in a wide range of physiological, biochemical, and molecular processes in plants. Photosynthesis, the most fundamental and intricate physiological process in all green plants, is also severely affected in all its phases by such stresses. Since the mechanism of photosynthesis involves various components, including photosynthetic pigments and photosystems, the electron transport system, and CO₂ reduction pathways, any damage at any level caused by a stress may reduce the overall photosynthetic capacity of a green plant. Details of the stress-induced...

The photosynthetic performance of sterile and fertile sporophytes in a natural population of the fern Dryopteris affinis

L. Paoli, M. Landi

Photosynthetica 2013, 51(2):312-316 | DOI: 10.1007/s11099-013-0022-5

We studied the photosynthetic performance of sterile and fertile sporophytes in a natural population of the fern Dryopteris affinis growing within a riparian forest (Central Italy) using chlorophyll (Chl) a fluorescence transients, the OJIP phase, where O is for the minimum fluorescence, P is for the peak (the maximum), and J and I are inflections. The "vitality" of the samples was assessed by the maximum quantum yield of primary photochemistry obtained indirectly from the fluorescence data (F_v/F_m); in the same way, the so-called performance index (PI_ABS) was obtained from fluorescence data. The photosynthetic...

Gas exchange of terrestrial and epiphytic orchids from Brazilian Atlantic Rainforest

M. V. Pires, A. A. F. Almeida, E. A. Santos, F. Z. Bertolde

Photosynthetica 2013, 51(2):317-320 | DOI: 10.1007/s11099-013-0020-7

Leaf gas exchange of terrestrial and epiphytic orchids from the Atlantic Rainforest in northeast Brazil was investigated under artificial growth conditions. The terrestrial orchids showed higher values of all photosynthetic parameters in comparison to epiphytic ones. There was a close relationship between P _N and g _s for both terrestrial and epiphytic orchids. Taken together, our results demonstrated that the photosynthetic parameters were related to the specific growth habits of the orchids under study.

Paul Gordon Jarvis

M. V. Marek

Photosynthetica 2013, 51(2):161-162 | DOI: 10.1007/s11099-013-0029-y