Drought tolerance monitoring of apple rootstock M.9-T337 based on infrared and fluorescence imaging

D.T. GAO, C.Y. SHI, Q.L. LI, Z.F. WEI, L. LIU, J.R. FENG

Photosynthetica 2021, 59(SI):458-467 | DOI: 10.32615/ps.2021.035  

Apple rootstock seedling M.9-T337 was selected to explore the effect of drought stress. The findings indicated that the relative water content of both the leaf and soil gradually decreased with an increase in drought stress. The water-use efficiency of the leaves increased gradually but decreased sharply after 20 d of drought. Changes in the gas-exchange parameters and chlorophyll fluorescence parameters reflected the gradual decrease in the photosynthetic capacity of the plants with drought stress duration. Infrared thermal imaging showed significant temperature differences between the drought-stressed and control plants after 15 d of drought treatment....

Towards the quantitative and physically-based interpretation of solar-induced vegetation fluorescence retrieved from global imaging

S. VAN WITTENBERGHE, N. SABATER, M.P. CENDRERO-MATEO, C. TENJO, A. MONCHOLI, L. ALONSO, J. MORENO

Photosynthetica 2021, 59(SI):438-457 | DOI: 10.32615/ps.2021.034  

Due to emerging high spectral resolution, remote sensing techniques and ongoing developments to retrieve the spectrally resolved vegetation fluorescence spectrum from several scales, the light reactions of photosynthesis are receiving a boost of attention for the monitoring of the Earth's carbon balance. Sensor-retrieved vegetation fluorescence (from leaf, tower, airborne or satellite scale) originating from the excited antenna chlorophyll a molecule has become a new quantitative biophysical vegetation parameter retrievable from space using global imaging techniques. However, to retrieve the actual quantum efficiencies, and hence a true photosynthetic...

Chlorophyll fluorescence imaging for process optimisation in horticulture and fresh food production

W.B. HERPPICH

Photosynthetica 2021, 59(SI):422-437 | DOI: 10.32615/ps.2021.033  

Chlorophyll a fluorescence analysis (CFA) has been accepted to study postharvest activity and stability of photosynthesis of vegetables and salad greens, and some fruits. Commercial chlorophyll fluorescence imaging (CFI) systems may provide additional insight into spatial and temporal dynamics of photosynthesis. This yields valuable information on the effects of postharvest handling and processing (sorting, cutting, packaging, etc.) on physiological activity and 'internal quality' of green produce, and its changes. Here, meaning and physiological basics of relevant fluorescence parameters is briefly summarised, while major focus is on...

The love-hate relationship between chlorophyll a and water in PSII affects fluorescence products

C.R. GUADAGNO, D.P. BEVERLY, B.E. EWERS

Photosynthetica 2021, 59(SI):409-421 | 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...

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 2021, 59(SI):399-408 | 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...

Can chlorophyll fluorescence imaging make the invisible visible?

R. VALCKE

Photosynthetica 2021, 59(SI):381-398 | 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...

Multi-colour fluorescence imaging of photosynthetic activityand plant stress

H.K. LICHTENTHALER

Photosynthetica 2021, 59(SI):364-380 | 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...

In honor of Hartmut Karl Lichtenthaler

G. GOVINDJEE

Photosynthetica 2021, 59(SI):361-363 | 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.

Role of beneficial elements in plants: implications for the photosynthetic process

E. LO PICCOLO, C. CECCANTI, L. GUIDI, M. LANDI

Photosynthetica 2021, 59(2):349-360 | DOI: 10.32615/ps.2021.032  

Essential macro- and microelements availability strictly influences photosynthetic process as well as the overall plant status. Besides essential macro- and micronutrients, a group of other elements described as 'beneficial' has been proposed to ameliorate plant performances under optimal and/or stressful conditions. The first explanation of the term 'essential', as suggested by Arnon and Stout in 1939, defined beneficial elements as not essentials since they are not necessary for plants to complete their life cycle. However, at low amounts, they can exert promoting effects on plant performances, including photosynthesis. In this review, we summarize...

Ethylene-dependent effects of fusaric acid on the photosynthetic activity of tomato plants

N. IQBAL, Z. CZÉKUS, A. ÖRDÖG, P. POÓR

Photosynthetica 2021, 59(2):337-348 | 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...

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 2021, 59(2):327-336 | 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...

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 2021, 59(2):313-326 | 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...

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 2021, 59(2):303-312 | 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...

The changes of PSII supercomplex stoichiometry in egy1 mutants are related to chlorophyll b deficiency

M. ADAMIEC, L. MISZTAL, M. CIESIELSKA, R. LUCIŃSKI

Photosynthetica 2021, 59(2):294-302 | 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 2021, 59(2):286-293 | 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...

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 2021, 59(2):277-285 | 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...

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 2021, 59(2):268-276 | 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...

Prof. Dr. Klaus Kloppstech - Always ahead, but never pushing forward. Impressive research without a tendency to overstatement

B. GRIMM

Photosynthetica 2021, 59(2):266-267 | DOI: 10.32615/ps.2021.024  

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 2021, 59(2):256-265 | 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...

Application of fast light-readapted plants for measurement of chlorophyll fluorescence and P₇₀₀ light absorption with the RLC method

E.A. LYSENKO

Photosynthetica 2021, 59(2):245-255 | 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 2021, 59(2):238-244 | 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...

Professor Giorgio Forti

R.C. JENNINGS

Photosynthetica 2021, 59(2):237 | DOI: 10.32615/ps.2021.022  

A comparison of the photosynthesis response to arsenic stress in two Pteris cretica ferns

V. ZEMANOVÁ, D. PAVLÍKOVÁ, F. HNILIČKA, M. PAVLÍK, H. ZÁMEČNÍKOVÁ, T. HLAVSA

Photosynthetica 2021, 59(1):228-236 | DOI: 10.32615/ps.2021.014  

The present study investigated the effect of arsenic (As) on photosynthesis and other selected physiological parameters in two ferns. The ferns (Pteris cretica 'Albo-lineata' and 'Parkerii') subjected to As doses of 100 and 250 mg kg^-1 for three months, showed different As accumulation, which was higher in Albo-lineata. Overall, the obtained results indicated significant differences between studied ferns. The individual effects of As and growing period on all parameters were very variable. However, As doses generally caused a decrease of net photosynthetic rate, stomatal conductance, transpiration rate, maximum quantum yield of PSII,...

Improving photosynthetic characteristics and antioxidant enzyme activity of capsule wall and subtending leaves increases cotton biomass under limited irrigation system

N.N. LI, F. SHI, H.Y. GAO, A. KHAN, F.Y. WANG, X.H. KONG, H.H. LUO

Photosynthetica 2021, 59(1):215-227 | DOI: 10.32615/ps.2021.012  

The photosynthetic performance of the canopy boll-leaf system (BLS) reflects the material and energy exchange abilities between plant and external environment. A two-year field experiment determined the response to irrigation regimes [600 (W₁), 480 (W₂), and 360 (W₃) m³ ha^-1] of cotton BLS physio-biochemical traits. Decreasing irrigation, photochemical quenching coefficient, the electron transfer rate of PSII, chlorophyll, and stomata width of the BLS decreased; nonphotochemical quenching (NPQ), the activity of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), hydrogen peroxide...

Species-specific performance and trade-off between growth and survival in the early-successional light-demanding group

T.O. VIEIRA, L.S. SANTIAGO, I.A. PESTANA, E. ÁVILA-LOVERA, J.L.A. SILVA, A.P. VITÓRIA

Photosynthetica 2021, 59(1):203-214 | DOI: 10.32615/ps.2021.013  

We investigated if high irradiance imposes stress conditions and differently affects the performance of species from the early-successional light-demanding group and if the costs associated with plasticity underlie the trade-off between growth and survival. Survival, growth, chlorophyll a fluorescence, and carbon stable isotopic ratio (δ¹³C) were measured in seedlings of four tree species in a restoration area in the Atlantic Forest under full-sun exposure and partial shading treatments. The maximal quantum yield of PSII indicated stress conditions mainly in the full-sun exposure treatment (values from 0.72 to 0.81). The δ¹³C...

Uniconazole and nitrogen fertilization trigger photosynthesis and chlorophyll fluorescence, and delay leaf senescence in maize at a high population density

I. AHMAD, S. AHMAD, M. KAMRAN, X.N. YANG, F.J. HOU, B.P. YANG, R.X. DING, T. LIU, Q.F. HAN

Photosynthetica 2021, 59(1):192-202 | DOI: 10.32615/ps.2021.011  

Reducing the leaf senescence rate could improve the grain yield in maize. In the present study, maize seeds were treated with uniconazole at concentrations of 0 and 25 mg kg^-1, and nitrogen was applied at 0, 150, and 225 kg ha^-1 to maize crop planted at a density of 105,000 plants ha^-1. Applying uniconazole and nitrogen reduced the leaf senescence rate by increasing the leaf area per plant, chlorophyll content, net photosynthetic rate, stomatal conductance, and transpiration rate_. Uniconazole and nitrogen increased the electron transport rate, photochemical quenching coefficient, variable fluorescence, maximal...

Quantifying light response of photosynthesis: addressing the long-standing limitations of non-rectangular hyperbolic model

Z.P. YE, S.H. DUAN, X.M. CHEN, H.L. DUAN, C.P. GAO, H.J. KANG, T. AN, S.X. ZHOU

Photosynthetica 2021, 59(1):185-191 | DOI: 10.32615/ps.2021.009  

Light intensity (I) fluctuates rapidly and is the most important environmental factor affecting photosynthesis. Accurate characterization of light-response curve of leaf-scale photosynthesis (P_N-I curve) is fundamental for understanding P_N-I relations at the whole-plant and ecosystem scales. A robust P_N-I model should be accurate in reproducing P_N-I curves over light-limited, light-saturated, and photoinhibitory I levels, and ideally returning key quantitative traits defining the curves, including initial slope of increase (α), dark...

Physiological changes of three woody plants exposed to progressive salt stress

Y. LU, F.J. ZENG, X.Y. LI, B. ZHANG

Photosynthetica 2021, 59(1):171-184 | DOI: 10.32615/ps.2021.007  

The saline character of water imposes restrictions on plant growth and survival in the Taklamakan Desert, China. Experiments were conducted on woody plant species, Tamarix ramosissima, Populus euphratica, and Haloxylon ammodendron grown under different levels of salinity to elucidate their adaptation to a saline environment. H. ammodendron accumulated large amounts of Na⁺ and Cl^- in leaves. P. euphratica restricted redundant Na⁺ and Cl^- transport to the shoots treated with lower NaCl concentrations. Na⁺ in leaves of T. ramosissima accumulated significantly...

Photosynthesis of grape leaves with 'OSC' trellis and cordon based on data model fitting

F.C. ZHANG, H.X. ZHONG, X.M. ZHOU, S.A. HAN, M. WANG, J.Z. HAO, X.Y. WU, M.Q. PAN

Photosynthetica 2021, 59(1):160-170 | DOI: 10.32615/ps.2021.010  

The photosynthetic parameters of 'Flame Seedless' and 'Red Globe' grape leaves in oblique single cordon (OSC) vine along the ditch and traditional single cordon (TSC) vine were determined using the CIRAS-2 photosynthetic system. The photosynthesis of leaves was studied using the Gaussian multi-peak model, Yezipiao's model, and the extended Freundlich's model fitting methods. The results showed that the correlation coefficients of the three data models fitting the field data were between 0.89 and 0.97. The three models can be used to analyze photosynthesis of grape leaves. In this paper, the physical significance of indicators obtained by extended...

Inhibition of photosynthesis in Melia azedarach and Ligustrum lucidum induced by manganese toxicity using OJIP chlorophyll a fluorescence transient

M.S. LIU, X.H. HUANG, R.J. WANG, H.Y. XU, F. ZHU

Photosynthetica 2021, 59(1):148-159 | DOI: 10.32615/ps.2021.006  

Manganese (Mn) excess is a major abiotic stress for plant growth. In the present study, we investigated the effects of Mn on photosynthesis in Ligustrum lucidum and Melia azedarach leaves using chlorophyll fluorescence transients. Both plant species were exposed to two Mn concentrations (0.5 and 1 mmol) for 10 and 30 d. Results showed that excess Mn significantly inhibited photosynthesis. With the increase of Mn concentration and stress time, the inhibition was more serious. Mn stress impaired PSII at the donor and the acceptor side by damaging the oxygen-evolving complex and limiting electron transport downstream of Q_A in...