Photosynthetica - Ahead of Print
In honor of Hartmut Karl Lichtenthaler
G. GOVINDJEE
Photosynthetica X:X | DOI: 10.32615/ps.2020.080 
We honor here Hartmut Karl Lichtenthaler, a pioneer of plant physiology, plant biochemistry, plant biophysics, plant molecular biology, and stress physiology. His contributions to the ingenious use of chlorophyll a fluorescence imaging in understanding the physiological processes in leaves stand out. We wish him many happy and productive years of research and educating others.
Application of fast light-readapted plants for measurement of chlorophyll fluorescence and P700 light absorption with the RLC method
E.A. Lysenko
Photosynthetica X:X | DOI: 10.32615/ps.2021.015
The rapid light curve method is a time-saving approach to the measurement of photosynthetic processes over a wide spectrum of light intensities. The adaptation to darkness enables the calculation of a complete set of coefficients for chlorophyll (Chl) fluorescence and P700 light absorption; however, dark-adapted plants demonstrate drastically different patterns of Chl fluorescence than that of light-adapted plants. The present work compared light-adapted barley plants without dark adaptation (L), and barley plants adapted to darkness and readapted to light for 7.5 min (D/L). The rapid light curves were generally similar in both the L and...
Comparison of water depth tolerance in two major wetland macrophytes, Phragmites australis and Typha angustifolia
U. SONG
Photosynthetica X:X | DOI: 10.32615/ps.2021.016
Two major emergent macrophytes, Phragmites australis and Typha angustifolia, show a clear zonation with respect to water depth, i.e., P. australis occupies shallower water than T. angustifolia. However, the reasons for this interspecific difference is unclear. Therefore, this study focused on the features that enable T. angustifolia to survive at greater water depths than P. australis. In both outdoor and greenhouse experiments, P. australis did not survive at the deepest water depth and showed significantly lower biomass, nitrogen content, and photosynthesis in most deep and/or aerated water...
Can chlorophyll fluorescence imaging make the invisible visible?
R. VALCKE
Photosynthetica X:X | DOI: 10.32615/ps.2021.017
Chlorophyll fluorescence has developed into a well-established noninvasive technique to study photosynthesis and by extension, the physiology of plants and algae. The versatility of the fluorescence analysis has been improved significantly due to advancements in the technology of light sources, detectors, and data handling. This allowed the development of an instrumention that is effective, easy to handle, and affordable. Several of these techniques rely on point measurements. However, the response of plants to environmental stresses is heterogeneous, both spatially and temporally. Beside the nonimaging systems, low- and high-resolution imaging systems...
Effects of sowing methods and nitrogen rates on photosynthetic characteristics, yield, and quality of winter wheat
H. NOOR, Q. WANG, M.A. ISLAM, M. SUN, W. LIN, A.X. REN, Y. FENG, S.B. YU, N. FIDA, S.F. DONG, P.R. WANG, L. LI, Z.X. WANG, R.R. ZHANG, Q.L. ZHAO, P.C. DING, Z.Q. GAO
Photosynthetica X:X | DOI: 10.32615/ps.2021.018
Sustainability of winter wheat yield under dryland conditions depends on improvements in crop photosynthetic characteristics and crop yield. Therefore, studying the effects of different sowing methods and nitrogen rates on photosynthetic characteristics of flag leaves, nitrogen translocation, and yield could be an effective strategy to improve the crop yield. In this study, four nitrogen application concentrations and two sowing methods were used. The results showed that the photosynthetic rates were the highest at different stages of wide-space sowing (WSS) after flowering. Nitrogen concentration of 240 kg ha-1 improved the photosynthetic...
Biochemical and photosystem characteristics of wild-type and Chl b-deficient mutant in tree peony (Paeonia suffruticosa)
L.X. ZHANG, Q.S. CHANG, X.G. HOU, S.D. CHEN, Q.M. ZHANG, J.Z. WANG, S.D. LIU, S. LI
Photosynthetica X:X | DOI: 10.32615/ps.2021.019
In order to explore the adaptive strategies of tree peony yl1 mutant in response to photooxidative stress, the changes of biochemical parameters, chlorophyll fluorescence, and the modulated 820-nm reflection of yl1 mutant and wild-type plants were compared. We found the activities of superoxide dismutase and catalase, the contents of soluble protein, proline, superoxide radicals, hydrogen peroxide, malondialdehyde, and relative electrical conductivity were significantly higher than those of the wild type. The photochemical efficiency of PSII significantly decreased, while the proportion of heat dissipation of yl1 mutant increased...
Multi-colour fluorescence imaging of photosynthetic activity and plant stress
H.K. LICHTENTHALER
Photosynthetica X:X | DOI: 10.32615/ps.2021.020
Imaging the four fluorescence bands of leaves, the red (F690) and far-red (F740) chlorophyll (Chl) fluorescence as well as the blue (F440) and green (F520) fluorescence of leaves and the corresponding fluorescence ratios is a fast and excellent nondestructive technique to detect the photosynthetic activity and capacity of leaves, of gradients over the leaf area as well as the effect of various strain and stress parameters on plants. This review primarily deals with the first and pioneering multi-colour fluorescence imaging results obtained since the mid-1990s in a cooperation with French colleagues in Strasbourg...
Short-term photoacclimation and photoregulation strategies of Sargassum horneri in response to temperature and light
Z.H. ZHONG, Y. WANG, S. QIN, L.C. ZHUANG, J.J. LI, W.L. SONG, Z.Y. LIU
Photosynthetica X:X | DOI: 10.32615/ps.2021.021
Sargassum horneri (Turner) C. Agardh is a genus of brown algae and plays an important role in marine ecosystem. However, the inhabiting area of S. horneri has been decreasing sharply in China. To understand the photoacclimation and photoregulation strategies of S. horneri in responses to temperature and light, S. horneri was cultured under different temperatures [18℃ (LT) and 26℃ (HT)] and light intensities [60 μmol(photon) m-2 s-1 (LL) and 120 μmol(photon) m-2 s-1 (HL)] for 7 d, and then the chlorophyll a fluorescence parameters were measured. The results...
Professor Giorgio Forti - Obituary
R.C. JENNINGS
Photosynthetica X:X | DOI: 10.32615/ps.2021.022
Professor Giorgio Forti passed away on March 1, 2021 in his Milano home. Giorgio was the father of modern photosynthetic research in Italy. His contribution to photosynthesis studies for over 50 years is respected and acknowledged internationally.
The love-hate relationship between chlorophyll a and water in PSII affects fluorescence products
C.R. GUADAGNO, D.P. BEVERLY, B.E. EWERS
Photosynthetica X:X | DOI: 10.32615/ps.2021.023
Chlorophyll a (Chl a) has an asymmetrical molecular organization, which dictates its orientation and the location of the pigment in the mature photosynthetic apparatus. Although Chl a fluorescence (ChlF) is widely accepted as a proxy for plant photosynthetic performance under countless stress conditions and across species, a mechanistic understanding of this causality is missing. Since water plays a much greater role than solvent for the photosynthetic machinery, elucidating its influence on Chl a may explain the reliable reflection of plant stress response in the ChlF signal. We examine the effect of hydration from well-watered...
Prof. Dr. Klaus Kloppstech - Always ahead, but never pushing forward. Impressive research without a tendency to overstatement
B. GRIMM
Photosynthetica X:X | DOI: 10.32615/ps.2021.024
t happened still in the former era of molecular biology when PCR and generation of transgenic plants were not invented. And plant scientists recall times long past, when enormous efforts were necessary to extract RNA and DNA and to study translation of single mRNA species. Some milestones in the understanding of stress- and light-induced gene expression are associated with the name of Klaus Kloppstech. He sadly passed away on February 15, 2021.
Screening of highly efficient photosynthetic hybrids of Oryza officinalis and analysis of their photosynthetic pathway genes
E.X. LI, F.Y. YIN, C. LI, D.Y. KAN, J.H. YOU, S.Q. XIAO, Z.Q. CHENG, X. KE
Photosynthetica X:X | DOI: 10.32615/ps.2021.025
Hereditary properties of strong growth and huge accumulation of biomass in Oryza officinalis exhibit a great potential; however, the genes that code for its high photosynthesis performance are not established. This study screened eight hybrids, using biomass accumulation and photosynthesis analysis, based on the introgression lines constructed by analyzing distant hybridization patterns between Oryza officinalis and cultivars HY-8. We designed 23 primer pairs using transcriptome sequencing of Oryza officinalis and screened two types of photosynthetic enzymes: phosphoenolpyruvate carboxylase (PEPC) and pyruvate...
A comparison of chlorophyll fluorescence transient measurements, using Handy PEA and FluorPen fluorometers
B. PADHI, G. CHAUHAN, D. KANDOI, A. STIRBET, B.C. TRIPATHY, G. GOVINDJEE
Photosynthetica X:X | DOI: 10.32615/ps.2021.026
We provide here a general introduction on chlorophyll (Chl) a fluorescence, then we present our measurements on fast (< 1 s) induction curves (the so-called OJIP transients) on dark-adapted intact leaves of Arabidopsis thaliana, under five different light intensities [in the range of ~ 500 to ~ 3,000 µmol(photons) m‒2 s‒1] using two different instruments: Handy PEA (Hansatech Instruments, UK; excitation light, 650 nm) and FluorPen (model FP-110; Photon Systems Instruments, The Czech Republic; excitation light, 470 nm). We then discuss the observed differences...
The changes of PSII supercomplex stoichiometry in egy1 mutants are related to chlorophyll b deficiency
M. ADAMIEC, L. MISZTAL, M. CIESIELSKA, R. LUCIŃSKI
Photosynthetica X:X | DOI: 10.32615/ps.2021.027
EGY1 is a chloroplast metalloprotease, the physiological role of which remains elusive. The changes observed in physiology and gene expression in egy1 mutants indicate that lack of the protease leads to yellow-green phenotype, changes in stoichiometry in PSII complexes, and early senescence. However, the knowledge concerning the role of the EGY1 to maintain the PSII function remains elusive. The aim of our study was to gain a deeper insight into the role of EGY1 protease in maintaining proper stoichiometry of PSII complexes. We applied the blue native electrophoresis technique as well as the immunoblotting method to investigate the abundance...
Changes in grapevine berry skin photochemistry may support metabolic responses to postharvest treatment by ultraviolet light
K. CSEPREGI, P. TESZLÁK, A. RÁCZ, Gy. CZÉGÉNY, L. KŐRÖSI, É. HIDEG
Photosynthetica X:X | DOI: 10.32615/ps.2021.028
Harvested mature berry clusters of two white table grape cultivars were used to study the effects of postharvest UV irradiation. One cultivar, 'Queen of Vineyard' (QV), had higher light-acclimated PSII quantum yield, higher phenolic contents, and stronger total antioxidant capacities than the other, 'White Sultana' (WS). These differences were maintained throughout the experiment. Responses of the two cultivars to a 30-min UV irradiation were also different. Antioxidant capacities and flavonol, especially quercetin-3-O-glucuronide, contents were lower 2 h after the UV treatment in both cultivars and recovered in QV but not in WS berry skins...
Ethylene-dependent effects of fusaric acid on the photosynthetic activity of tomato plants
N. IQBAL, Z. CZÉKUS, A. ÖRDÖG, P. POÓR
Photosynthetica X:X | DOI: 10.32615/ps.2021.029
Fusaric acid (FA) is one of the potential toxins produced by pathogenic Fusarium species which exerts oxidative stress and cell death in plants. In this work, the effects of different concentrations of FA were investigated on the photosynthetic activity in leaves of wild type and Never ripe (Nr) tomato plants to reveal the potential role of ethylene under mycotoxin exposure. FA induced a significant ethylene emission from leaves in a concentration- and time-dependent manner. FA (1 mM) decreased the maximal and effective quantum yields of PSII and PSI in both tomato genotypes but photoprotective processes, such as the nonphotochemical...
How does moderate drought affect quantum yield and the regulation of sugar metabolism at low temperature in durum wheat (Triticum durum L.)?
R. KHALIL, J. TAJTI, K.Á. HAMOW, K.O. GONDOR, E. Darko, N. Elsayed, Z. NAGY, G. SZALAI, T. JANDA, I. MAJLÁTH
Photosynthetica X:X | DOI: 10.32615/ps.2021.030
Currently, limited knowledge is available about the combined effects of drought and light in case of cold stress. The investigation of quantum yield kinetics may help understand how plants utilize light under adverse environmental conditions. In the present study, mild drought helped preserve quantum yield in durum wheat (Triticum durum L.). The time necessary to reach the steady-state actual quantum yield corresponded with the cold sensitivity. Possible underlying mechanisms induced by drought, such as the reduction of malondialdehyde content, accumulation of D-sorbit, and glycine betaine, may have protected photosynthetic apparatus and integrity...
Exogenous melatonin ameliorates salinity-induced oxidative stress and improves photosynthetic capacity in sweet corn seedlings
D.Y. WANG, J. WANG, S.H. SHI, L.X. HUANG, M. ZHU, F.H. LI
Photosynthetica X:X | DOI: 10.32615/ps.2021.031
Melatonin (MT) is involved in physiological processes in plants under abiotic stress. In this study, we investigated the effects of melatonin on maize photosynthetic and antioxidant capacities under salinity stress. Our findings indicated salinity stress significantly inhibited maize growth. However, exogenous MT promoted maize growth and antioxidant capacity. Superoxide dismutase, peroxidase, and catalase increased by 138.8, 38.7, and 32.0%, respectively, while H2O2 and malondialdehyde decreased by 23 and 31%, respectively. Exogenous MT also improved maize photosynthesis under salinity stress. Net photosynthetic rate, transpiration...