On "P750s" in cyanobacteria: A historical perspective

G. GOVINDJEE, L.O. BJÖRN, R.E. BLANKENSHIP

Photosynthetica 2024, 62(4):406-408 | DOI: 10.32615/ps.2024.042  

Impact of exogenous rhamnolipids on plant photosynthesis and biochemical parameters under prolonged heat stress

M.A. BOUCHRATI, S. VILLAUME, J.F. GUISE, I. FEUSSNER, N. VAILLANT-GAVEAU, S. DHONDT-CORDELIER

Photosynthetica 2024, 62(4):393-405 | DOI: 10.32615/ps.2024.041  

High temperatures severely affect plant growth and development leading to major yield losses. These temperatures are expected to increase further due to global warming, with longer and more frequent heat waves. Rhamnolipids (RLs) are known to protect several plants against various pathogens. To date, how RLs act under abiotic stresses is unexplored. In this study, we aimed to investigate whether RLs could modify Arabidopsis thaliana physiology during prolonged heat stress. Measurement of leaf gas exchange and chlorophyll fluorescence showed that heat stress reduces photosynthetic rate through stomatal limitation and reduction of photosystem...

Chloroplast antioxidant reactions associated with zinc-alleviating effects on iron toxicity in wheat seedlings

Y.L. XU, J.Y. GUO, Z. ZHANG, R.R. MA, H. MA, Y. ZHANG, Y.L. YANG

Photosynthetica 2024, 62(4):381-392 | DOI: 10.32615/ps.2024.038  

This study aimed to explore the mechanism by which Zn retards Fe toxicity by analyzing the morphological, photosynthetic, and chloroplast physiological parameters of wheat seedlings treated with either single or combined Zn and Fe. Different behavior of the seedlings was observed under untreated and treated conditions. The most discriminating quantitative traits were associated with leaf area, biomass dry mass and fresh mass, net photosynthetic rate, intercellular CO₂ concentration, stomatal conductance, transpiration rate of seedlings, Hill reaction, Mg²⁺-ATPase and Ca²⁺-ATPase activities, malondialdehyde and O₂^*-...

Using hyperspectral reflectance to detect changes in photosynthetic activity in Atractylodes chinensis leaves as a function of decreasing soil water content

J. LIU, Y. WANG, X.M. LIN, Z.C. XUE, F.R. ZENG

Photosynthetica 2024, 62(4):372-380 | DOI: 10.32615/ps.2024.040  

Application of hyperspectral reflectance technology to track changes in photosynthetic activity in Atractylodes chinensis (A. chinensis) remains underexplored. This study aimed to investigate the relationship between hyperspectral reflectance and photosynthetic activity in the leaves of A. chinensis in response to a decrease in soil water content. Results demonstrated that the reflectance in both the visible light and near-infrared bands increased in conjunction with reduced soil water content. The derived vegetable indices of photochemical reflection index (PRI) and the pigment-specific simple ratio of chlorophyll b...

Ascorbic acid is involved in melatonin-induced salinity tolerance of maize (Zea mays L.) by regulating antioxidant and photosynthetic capacities

M. ZHU, T. GUO, Y.B. LIU, R. XIAO, T. YU, J.X. HUANG, W.L. DU, X.M. ZHONG, B. SONG, F.H. LI

Photosynthetica 2024, 62(4):361-371 | DOI: 10.32615/ps.2024.039  

Melatonin (MT), an indole compound, can boost plant growth under abiotic stress conditions. This experiment aims to elucidate the synergistic effect of MT and ascorbic acid (AsA) in mitigating salinity stress by assessing the photosynthetic and antioxidant capacity of the maize inbred lines H123 and W961. The results indicated that exogenous MT and AsA significantly improved photosynthetic efficiency and biomass of maize under salinity stress. Additionally, exogenous MT and AsA also improved antioxidant enzyme activities, promoted regeneration of AsA and GSH, decreased reactive oxygen species contents, suppressed Na⁺ accumulation, and improved...

Hydraulic conductivity and photosynthetic capacity of seedlings of Coffea canephora genotypes

J.A. MACHADO FILHO, P.R. COSTA, L. DE O. ARANTES, S. DOUSSEAU-ARANTES, W.P. RODRIGUES, J. CRASQUE, E. CAMPOSTRINI

Photosynthetica 2024, 62(4):351-360 | DOI: 10.32615/ps.2024.031  

The aim was to investigate the morphological, photosynthetic, and hydraulic physiological characteristics of different genotypes of Coffea canephora under controlled cultivation conditions. Growth, conductance, and hydraulic conductivity of the root system of 16 C. canephora genotypes were evaluated in Experiment 1 (November 2013). In Experiment 2 (December 2014), in addition to the previous characteristics, gas exchange, photochemical efficiency, leaf water potential, and leaf hydraulic conductivity were investigated in five genotypes. No significant differences were observed in specific leaf hydraulic conductance, stomatal density,...

Effects of tillage methods on photosynthetic performance of different functional leaf groups of summer maize in coastal saline-alkali farmland

H.-X. LI, †, Y.-F. CHENG, J.-X. FENG, G.-L. FU, G.-L. LIU, P. LIU, H. REN, H.-Z. WANG, B. ZHAO, G. LI

Photosynthetica 2024, 62(4):339-350 | DOI: 10.32615/ps.2024.037  

This study aims to determine the changes in the photosynthetic performance of leaves at different leaf positions and their correlation and to screen out the basic tillage methods suitable for improving the yield. The decrease in soil salt content significantly improved the PSII performance index and quantum yield for electron transport of the bottom leaf group, synergistically enhanced the photosynthetic performance of summer maize leaves (especially the bottom leaf group), and enhanced the correlation between the bottom, middle (including the ear leaf), and upper leaf groups. Under subsoiling tillage conditions, the bottom leaves could produce more...

Honoring Hartmut Karl Lichtenthaler, innovative pioneer of photosynthesis, on his 90^th birthday

G. GOVINDJEE, T.D. SHARKEY, A. MELIS

Photosynthetica 2024, 62(4):326-338 | DOI: 10.32615/ps.2024.017  

We honor Professor Hartmut Karl Lichtenthaler, a versatile pioneer of photosynthesis research, plant physiology, isoprenoid biochemistry, and stress physiology of plants, for his groundbreaking and creative contributions to plant science. His innovative research on the chemical composition, ultrastructure, and function of chloroplasts and his detection of the major methylerythritol 4-phosphate (MEP) isoprenoid biosynthetic pathway in plants is key to our current understanding of the physiology and biochemistry of photosynthesis systems. His ingenious use of the powerful laser-induced chlorophyll a fluorescence imaging has helped us better understand...

On the discovery of the two-light effect on chlorophyll a fluorescence: Quenching of chlorophyll a fluorescence of Photosystem II by Photosystem I light

G. GOVINDJEE

Photosynthetica 2024, 62(3):302-304 | DOI: 10.32615/ps.2024.035  

LETTER TO THE EDITOR

U. SCHREIBER

Photosynthetica 2024, 62(3):314-317 | DOI: 10.32615/ps.2024.036  

LETTER TO THE EDITOR

G. GARAB

Photosynthetica 2024, 62(3):289-291 | DOI: 10.32615/ps.2024.032  

Contributions of David Mauzerall to photosynthesis research - celebrating his 95^th birthday

G. GOVINDJEE, O. CANAANI, R.A. CELLARIUS, B. DINER, E. GREENBAUM, H.J.M. HOU, N.Y. KIANG, J.S. LINDSEY, D.L. MAUZERALL, M.E. MAUZERALL, M. SEIBERT, A. STIRBET

Photosynthetica 2024, 62(3):271-288 | DOI: 10.32615/ps.2024.029  

We honor here Professor David Mauzerall, a pioneer in the fields of photochemistry and photobiology of porphyrins and chlorophylls in vitro and in vivo, on the occasion of his 95^th birthday. Throughout his career at The Rockefeller University, he refined our understanding of how chlorophyll converts light energy into chemical energy. He exploited top-of-the-line laser technology in developing photoacoustics and a variety of other innovative experimental approaches. His experimental work and conceptual insights contributed greatly to our understanding of photosynthesis and the possible role of photosynthesis in the origin of...

Vapor-pressure-deficit-controlled temperature response of photosynthesis in tropical trees

C.E. EZE, K. WINTER, M. SLOT

Photosynthetica 2024, 62(3):318-325 | DOI: 10.32615/ps.2024.034  

Rising temperatures can affect stomatal and nonstomatal control over photosynthesis, through stomatal closure in response to increasing vapor pressure deficit (VPD), and biochemical limitations, respectively. To explore the independent effects of temperature and VPD, we conducted leaf-level temperature-response measurements while controlling VPD on three tropical tree species. Photosynthesis and stomatal conductance consistently decreased with increasing VPD, whereas photosynthesis typically responded weakly to changes in temperature when a stable VPD was maintained during measurements, resulting in wide parabolic temperature-response curves. We have...

Relationship between photosynthetic performance and yield loss in winter oilseed rape (Brassica napus L.) under frost conditions

P. DĄBROWSKI, Ł. JEŁOWICKI, Z.M. JASZCZUK, S. MAIHOUB, J. WRÓBEL, H.M. KALAJI

Photosynthetica 2024, 62(3):240-251 | DOI: 10.32615/ps.2024.025  

Winter oilseed rape (Brassica napus L.), the principal oilseed crop in Europe, is notably vulnerable to spring frosts that can drastically reduce yields in ways that are challenging to predict with standard techniques. Our research focused on evaluating the efficacy of photosynthetic efficiency analysis in this crop and identifying specific chlorophyll fluorescence parameters severely impacted by frost, which could serve as noninvasive biomarkers for yield decline. The experiments were carried out in semi-controlled conditions with several treatments: a control, one day at -3°C, three days at -3°C, one day at -6°C, and three days at -6°C. We...

Physiological response to low-nitrogen stress and comprehensive evaluation in four rice varieties

Y.F. ZHANG, H. CAI, E.T. YOU, X.Q. QIAO, Z.P. GAO, G.X. CHEN

Photosynthetica 2024, 62(3):252-262 | DOI: 10.32615/ps.2024.028  

Rice (Oryza sativa L.) research has rarely focused on the response to low-nitrogen stress in different subtypes previously and lacked a low-nitrogen tolerance evaluation system. Here, we investigated the physiological characteristics under moderate and low-nitrogen stress conditions in two japonica cultivars (NG46 and NG9108) and two indica cultivars (LYP9 and 9311). Using subordinate function analysis and principal component analysis, the low-nitrogen tolerance of four rice varieties was comprehensively evaluated; stomatal conductance, total carotenoid content, and nitrate reductase NR activity were taken as the low-nitrogen tolerance...

Light curve parametrization of three rice (Oryza sativa L.) cultivars based on mechanistic models

Z.P. YE, S.X. ZHOU, X.L. YANG, H.J. KANG, S.H. DUAN, F.B. WANG

Photosynthetica 2024, 62(3):305-313 | DOI: 10.32615/ps.2024.033  

This study aimed to assess variations in leaf gas-exchange characteristics, leaf pigment contents, and some intrinsic traits of photosynthetic pigment molecules in three rice cultivars (cv. JR3015, Wufengyou3015, and Jifengyou3015) using mechanistic models. The findings revealed that chlorophyll content varied significantly among the three cultivars, but not maximum electron transport rate. JR3015 had lower chlorophyll content but the highest eigen-absorption cross-section (σ_ik) and the lowest minimum average life-time of photosynthetic pigment molecules in the excited state (τ_min). Our results suggested that the highest...

Morphophysiological responses of black pepper to recurrent water deficit

T.R. FERREIRA, V.P. SALLIN, B. CERRI NETO, J. CRASQUE, A. PIRES, P.S. RODRIGUES, H. CHISTÉ, A.B.P. LIMA, J.A. MACHADO FILHO, L.O. ARANTES, J.M.S. LIRA, A.R. FALQUETO, S. DOUSSEAU-ARANTES

Photosynthetica 2024, 62(3):292-301 | DOI: 10.32615/ps.2024.030  

This study investigated the effects of recurrent water deficit on drought tolerance traits in black pepper (Piper nigrum L.) ʻBragantinaʼ. Plants were subjected to three cycles of water deficit followed by recovery periods. Water deficit reduced stomatal conductance, photosynthesis, transpiration, and water potential while increasing water-use efficiency. In addition, intercellular CO₂ concentration, leaf temperature, root starch, and adaptive morphological characteristics in leaves and roots increased. Despite these adaptations, plants did not recover vegetative growth after rehydration. The primary tolerance mechanisms...

Selenium improves wheat antioxidant capacity, photosynthetic capacity, and growth under cadmium stress

L.M. WU, N.H. LU

Photosynthetica 2024, 62(3):232-239 | DOI: 10.32615/ps.2024.027  

Cadmium stress (CS) induced the peroxide damage and inhibited wheat photosynthetic capacity and growth. Compared to CS, selenium (Se) application plus CS bolstered chlorophyll and carotenoid contents, photosynthetic rate, the maximum photochemical efficiency of PSII, the quantum yield of PSII photochemistry, and photochemical quenching, superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase, L-galactono-1,4-lactone dehydrogenase, and gamma-glutamylcysteine synthetase activities, ascorbic acid and glutathione contents, AsA/dehydroascorbic acid and GSH/oxidized glutathione, and decreased nonphotochemical quenching (q_N),...

High photosynthetic thermal tolerance in the Mediterranean halophyte Limoniastrum monopetalum

E. FIGUEROA-LUQUE, M.E. FIGUEROA, J.M. CASTILLO, A. DE CIRES, R. ÁLVAREZ, J. CAMBROLLÉ, B. GALLEGO-TÉVAR

Photosynthetica 2024, 62(3):263-270 | DOI: 10.32615/ps.2024.026  

The general increase in temperature, together with sudden episodes of extreme temperatures, are increasingly impacting plant species in the present climate change scenario. Limoniastrum monopetalum is a halophyte from the Mediterranean Basin, exposed to broad daily and seasonal changes in temperature and extreme high temperatures. We studied the photosynthetic responses (chlorophyll fluorescence dynamics and gas exchange) of L. monopetalum leaves exposed to temperatures from -7.5°C to +57.5°C under darkness in controlled laboratory conditions. L. monopetalum presented its optimum temperature for photosynthesis around +30°C. The...

Biochar alleviates single and combined effects of salinity and drought stress in faba bean plants

I. RAJHI, R. NEFISSI OUERTANI, N. FERCHICHI, B. KHIARI, L. EL-BASSI, H. MHADHBI

Photosynthetica 2024, 62(2):221-231 | DOI: 10.32615/ps.2024.019  

This study aimed to evaluate the impact of four biochar concentrations (0, 2, 5, and 8%) on single and interactive effects of salinity and drought stresses on the morphological, physiological, and photosynthetic parameters of faba bean plants. PCA analysis showed that plants displayed different behavior under non-stressed and stressed conditions. The most discriminating quantitative characters were related to plant biomass production and photosynthesis, especially shoot dry mass, root dry mass, plant fresh mass, internal CO₂ concentration, net CO₂ assimilation rate, and relative water content. The obtained results confirm the...

Chlorophyll and growth performance of biological sand-fixing materials inoculated on sandy desert surface

H.R. REN, L. TAO, J. REN, X.C. REN

Photosynthetica 2024, 62(2):213-220 | DOI: 10.32615/ps.2024.020  

Desert biocrusts play an important role in the control of desertification and artificial inoculation can promote the formation and development of biocrusts. Physiological and growth responses of biocrusts inoculated on desert surfaces were investigated to assess the effect of mixture ratio, inoculation times, and water supply under laboratory conditions. The application of biological sand-fixing material prepared by cultivated algae crust and polymeric composites in a 1:1 ratio accelerated the most accumulation of chlorophyll a in 0.55 mg kg^-1, thickness in 3.06 mm, and fresh mass in 0.69 g cm^-1, was the most beneficial...

LETTER TO THE EDITOR

H.M. KALAJI

Photosynthetica 2024, 62(2):212 | DOI: 10.32615/ps.2024.024  

Response to the article by Gyözö Garab in Photosynthetica (DOI: 10.32615/ps.2024.022) with the title: Revisiting the nonregulatory, constitutive nonphotochemical quenching of the absorbed light energy in oxygenic photosynthetic organisms

LETTER TO THE EDITOR

U. SCHREIBER

Photosynthetica 2024, 62(2):209-211 | DOI: 10.32615/ps.2024.023  

Response to the article by Gyözö Garab in Photosynthetica (DOI: 10.32615/ps.2024.022) with the title: Revisiting the nonregulatory, constitutive nonphotochemical quenching of the absorbed light energy in oxygenic photosynthetic organisms

Revisiting the nonregulatory, constitutive nonphotochemical quenching of the absorbed light energy in oxygenic photosynthetic organisms

G. GARAB

Photosynthetica 2024, 62(2):204-208 | DOI: 10.32615/ps.2024.022  

The present paper aims to open discussion on the information content, physical mechanism(s), and measuring protocols to determine the partitioning of the absorbed light energy in oxygenic photosynthetic organisms. Revisiting these questions is incited by recent findings discovering that PSII, in addition to its open and closed state, assumes a light-adapted charge-separated state and that chlorophyll a fluorescence induction (ChlF), besides the photochemical activity of PSII, reflects the structural dynamics of its reaction center complex. Thus, the photochemical quantum yield of PSII cannot be determined from the conventional ChlF-based protocol....

Changes of Cd content in chloroplasts are mirrored by the activity of photosystem I, but not by photosystem II

E.A. LYSENKO, V.V. KUSNETSOV

Photosynthetica 2024, 62(2):187-203 | DOI: 10.32615/ps.2024.018  

We searched for a direct Cd action on the photosynthetic electron transport chain using induced chlorophyll fluorescence and P₇₀₀ light absorption. Young barley and maize plants were treated with Cd in concentrations of toxic (80 μM) and nearly lethal (250 μM). The maximal and relative photochemical activities of PSI, its major limitation at the donor side, and partially acceptor-side limitation of PSII changed in agreement with Cd accumulation in the corresponding chloroplasts. Acceptor-side limitation of PSII increased with a direct Cd action at 80 μM that was overcome with an indirect Cd action at 250 μM. These alterations...

Influence of additional far-red light on the photosynthetic and growth parameters of lettuce plants and the resistance of the photosynthetic apparatus to high irradiance

A. SHMAREV, M. VERESHAGIN, P. PASHKOVSKIY, V.D. KRESLAVSKI, S.I. ALLAKHVERDIEV

Photosynthetica 2024, 62(2):180-186 | DOI: 10.32615/ps.2024.016  

The effects of additional far-red light (FRL) on the photosynthetic and growth parameters of Lactuca sativa plants grown for 30 d and on the photosynthetic activity of the plants under high irradiance [4 h; 1,500 μmol(photon) m^-2 s^-1] were studied. The plants were grown under coloured light-emitting diodes at a ratio of red light (RL): blue light (BL): green light (GL): far-red light (FRL) = 0.7:1:0.3:0.4 or RL:BL:GL:FRL = 0.7:1:0.3:0.8 (test, T). Additional FRL led to an increase in plant biomass, height, and leaf area but to a decrease in photosynthesis and respiration rates. However, PSII activity was greater in plants...

Selenite foliar application increased the accumulation of medicinal components in Paeonia ostii by promoting antioxidant capacity, reducing oxidative stress, and improving photosynthetic capacity

L.X. ZHANG, Q.S. CHANG, Y.L. HE, X.L. ZHAO, W. LIU, Q. GUO, K. CHEN, X.G. HOU

Photosynthetica 2024, 62(2):168-179 | DOI: 10.32615/ps.2024.012  

The effects of selenite (0, 15, 30, 45 mg L^-1) on physiological characteristics and medicinal components of Paeonia ostii were analyzed. The results showed that selenite application promoted the activity of superoxide dismutase and the contents of soluble sugar, proline, carotenoids, total flavonoids, and total polyphenols, and decreased the contents of reactive oxygen species, relative electrical conductivity, and malondialdehyde. In addition, selenite also increased chlorophyll content, improved electron transfer ability, PSI and PSII performance, and the coordination between PSI and PSII, which significantly improved photosynthetic...

Gas exchange and time to reach maximum rate of photosynthetic rateand their relationship with whole-plant traits in sugarcane in water abundant Louisiana, USA

P.Z. ELLSWORTH, P.M. WHITE Jr., J. TODD

Photosynthetica 2024, 62(2):158-167 | DOI: 10.32615/ps.2024.015  

Variety development of sugarcane (Saccharum spp. hybrids) is necessary to continue improving sugar yields and selecting photosynthetic traits can improve sugar production through increased carbon inputs. In this study, gas exchange and whole-plant measurements were made on 55 sugarcane genotypes in Louisiana. Variation in the relationship between photosynthetic rate and stomatal conductance suggests that sugarcane exhibits variation in both photosynthetic capacity and CO₂ substrate availability. Genotypes that reached maximum photosynthetic rate (TRMPR) in the gas-exchange cuvette more quickly had greater CO₂ assimilation...

Using chlorophyll fluorescence parameters and antioxidant enzyme activity to assess drought tolerance of spring wheat

S.V. ОSIPOVA, А.V. RUDIKOVSKII, А.V. PERMYAKOV, Е.G. RUDIKOVSKAYA, А.V. POMORTSEV, О.V. МUZALEVSKAYA, Т.А. PSHENICHNIKOVA

Photosynthetica 2024, 62(2):147-157 | DOI: 10.32615/ps.2024.014  

The improvement of phenotyping methods is necessary for large-scale screening studies of wheat (Triticum aestivum L.) drought tolerance. The objective of our research was to find out whether it is possible to use chlorophyll (Chl) fluorescence parameters instead of biochemical indicators of drought tolerance when screening wheat. We measured shoot biomass, gas exchange, as well as biochemical and Chl fluorescence indicators in 11 wheat genotypes grown under contrasting water supplies and differing in drought tolerance. The effect of drought on the traits was evaluated using the effect of size index. We made two independent rankings: one based...

Photosynthesis and hydrogen energy for sustainability: harnessing the sun for a greener future

B.D. KOSSALBAYEV, G. YILMAZ, H.G. OZCAN, G. SOYKAN, S. YALCIN, S.I. ALLAKHVERDIEV

Photosynthetica 2024, 62(2):138-146 | DOI: 10.32615/ps.2024.013  

At the dawn of the 21^st century, the rapid expansion of manufacturing plants and the widespread destruction of natural habitats significantly contributed to accelerating global warming. This phenomenon has led to severe droughts, irreversible agricultural damage, and substantial challenges in securing food supplies for the burgeoning global population. The alarming surge in atmospheric carbon dioxide concentrations underscores the urgent need to embrace clean energy technologies. To date, the primary goal of mankind is to develop innovative approaches to return Earth's ecology to its pre-industrial condition, as a century ago. The special...