Photosynthetica, 2026 (vol. 64), issue 3
A tribute to Ion C. Baianu (18 August 1947-10 February 2013):his 1982-1984 contributions to oxygenic photosynthesis
G. GOVINDJEE, A. STIRBET
Photosynthetica 2026, 64(3):137-139 | DOI: 10.32615/ps.2026.027 
Here we present the 1982-1984 collaborative research of Ion C. Baianu (18 August 1947-10 February 2013) with one of the authors (Govindjee) at the University of Illinois at Urbana-Champaign on the role of chloride in Photosystem II. Then, we provide a brief presentation of his general academic and research legacy.
The tolerance of Sphagneticola trilobata and its hybrid to cadmium stress
Q.L. ZHANG, Y. WANG, G.X. CHEN, X.W. ZHENG, N. WANG
Photosynthetica 2026, 64(3):140-147 | DOI: 10.32615/ps.2026.026
During the invasion process, Sphagneticola trilobata produced a hybrid with native species. In this study, the adaptability of S. trilobata and its hybrid was investigated under cadmium (Cd) stress. Results showed that the net photosynthetic rate and maximum quantum yield of PSII photochemistry of S. trilobata leaves were significantly lower than those in the hybrid, while malondialdehyde and electrolyte leakage were significantly higher than those in the hybrid. The accumulation of Cd in the hybrid was significantly higher than that in S. trilobata, and more active detoxification strategies were shown in the hybrid. The...
From water deficit to growth suppression: meta-analytic evidence for a functional hierarchy of drought adaptation in Hippophae rhamnoides
X.Y. SHI, Y. ZHAO, Y.E. BAI, D.M. YE, W.B. JIA, X.H. LI, Y.H. HE, H. LI
Photosynthetica 2026, 64(3):148-163 | DOI: 10.32615/ps.2026.023
Drought constrains shrub establishment and persistence in arid and semi-arid restoration systems. Although Hippophae rhamnoides is widely planted in northern China, its drought responses vary among studies, hindering the identification of stable indicators. We synthesized 3,855 treatment-control comparisons from 49 controlled experiments across 12 Chinese provinces using random-effects meta-analysis and structural equation modeling. Results showed that drought adaptation in H. rhamnoides follows a functional cascade. Water status and membrane stability were the most consistent early constraints, followed by strong suppression of photosynthetic...
Full-length transcriptome and RNA-Seq analyses reveal the molecular mechanism of light protection in Hosta ventricosa
X.J. QU, D.Y. CHE, X.H. JIANG, S.Q. LI, H.Z. LIU
Photosynthetica 2026, 64(3):164-177 | DOI: 10.32615/ps.2026.025
Hosta ventricosa is a popular shade-tolerant ornamental perennial vulnerable to high light, whose molecular mechanisms of high-light stress response remain unclear. To clarify this, we measured leaf morphology, photosynthetic physiology, and performed integrated analyses using PacBio full-length and Illumina transcriptome sequencing on plants under full sunlight (FS), moderate shade (MS), and deep shade (DS) treatments. The results indicated that MS showed optimal growth, whereas FS and DS inhibited growth, each associated with distinct gene expression profiles. High light induced VDE by 5.68-fold to activate the xanthophyll cycle and...
Plant stress detection through a chlorophyll content-dependent relationship between Fv/Fm and the photochemical reflectance index
D. OH, J.-H. RYU, K.-M. KIM, H. JEONG, H.-D. MOON, H. KIM, S. CHOI, B.-K. KIM, H. WON, H. YANG, J. CHO
Photosynthetica 2026, 64(3):178-185 | DOI: 10.32615/ps.2026.028
Optical sensing for plant stress detection requires physiologically relevant indices. Fv/Fm, representing the maximum quantum yield of photosystem II photochemistry, quantifies stress across species but requires dark adaptation, limiting field application. Photochemical reflectance index (PRI), a reflectance-based indicator of xanthophyll cycle activity, can be remotely measured, but its irregular variation complicates interpretation. Paddy rice was grown in temperature-gradient field chambers to evaluate Fv/Fm, PRI, and SPAD (soil-plant analysis development). Changes in Fv/Fm were associated...
Environmental conditions dictate the long-term photosynthetic and developmental response of lettuce to cold plasma priming
K. ©EDIVÁ, P. KÚR, J. MATOU©EK, H. AUER MALINSKÁ
Photosynthetica 2026, 64(3):186-199 | DOI: 10.32615/ps.2026.030
Cold plasma (CP) seed treatment is a promising non-chemical priming technique, yet its long-term physiological effects remain poorly understood and highly context-dependent. This study evaluated CP treatment (50-150 W) on lettuce seeds grown under controlled phytotron and semi-controlled greenhouse conditions. Germination kinetics, flowering dynamics, shoot biomass, chlorophyll fluorescence (OJIP), and leaf reflectance indices were assessed. CP consistently accelerated germination compared with the untreated control, with only minor differences among plasma power levels. Under stable phytotron conditions, higher plasma power (100-150 W) delayed flowering,...
Organic compounds as Photosystem II inhibitors and Cu2+ ligands: insights from primary screening
M.S. SHABANOVA, E.V. ZADNEPROVSKAYA, S.K. ZHARMUKHAMEDOV, R.G. VASILOV, M.S. KARACAN, S.I. ALLAKHVERDIEV
Photosynthetica 2026, 64(3):200-209 | DOI: 10.32615/ps.2026.032
The search for novel organic compounds as PSII inhibitors and copper (Cu2+) ligands addresses key agricultural challenges. Three novel compounds were synthesized and evaluated for PSII photochemical activity inhibition and Cu2+-chelating ability. Primary screening was performed by recording effects on minimal and maximal chlorophyll fluorescence levels in isolated thylakoids. Testing employed both direct (thylakoids + Cu2+ + compound) and reverse (thylakoids + compound + Cu2+) addition sequences, with measurements performed under short illumination (<10 s) to avoid photodynamic artifacts. The tested compounds...
Validation of the newly developed PlantECG fluorometer against three established chlorophyll fluorescence devices under progressive drought stress in pepper, tomato, and strawberry plants
H.M. KALAJI, P. DˇBROWSKI, A. AURIGA
Photosynthetica 2026, 64(3):210-222 | DOI: 10.32615/ps.2026.031
Comparing chlorophyll fluorescence data across different fluorometers remains challenging. We compared the new PlantECG fluorometer with PocketPEA, HandyPEA, and FluorPen in pepper (Capsicum annuum L.), tomato (Solanum lycopersicum L.), and strawberry (Fragaria × ananassa Duch.) under progressive drought (0-96 h without irrigation). The maximum quantum yield of PSII photochemistry (FV/FM) measured by PlantECG correlated strongly with all reference devices (R2 = 0.72-0.98), although PlantECG slightly overestimated FV/FM...
Determination of chlorophyll and carotenoid content in Mediterranean riparian forest species using visible spectroscopy
M. MARTÍNEZ MENA, M.D.L. SOTO ROSALES, D. GARCÍA DE JALÓN
Photosynthetica 2026, 64(3):223-231 | DOI: 10.32615/ps.2026.033
Leaf-level optical measurements are essential for monitoring Mediterranean riparian forests. This study used visible spectroscopy (400-750 nm) to determine and quantify leaf pigments in five species: Salix salviifolia, Fraxinus angustifolia, Alnus glutinosa, Populus nigra, and Prunus avium. We followed Hansmann's method for sample processing and quantified chlorophyll using Arnon's equation. We collected samples from sun-exposed leaves in spring under standardized conditions. Results indicated that Alnus glutinosa and Populus nigra exhibited the highest chlorophyll a concentrations [1.35 and 1.29...
Quantification of spatial heterogeneity of different chlorophyll fluorescence parameters over tomato leaf areas affected by Cd2+ stress
D. GIORDANO, A. SAADATI, A.M. ASHRAFI, L. RICHTERA, M. BARTÁK
Photosynthetica 2026, 64(3):232-244 | DOI: 10.32615/ps.2026.035
Cadmium impairs plant growth by inducing oxidative damage through excessive ROS production. Sulfur and nitrogen supplementation can affect Cd mobility, uptake, and toxicity. This study quantifies the spatial heterogeneity of Cd-induced photochemical limitation in Solanum lycopersicum leaves using chlorophyll fluorescence imaging, and examines Cd2+ distribution in roots, stems, and leaves of hydroponic plants treated with ammonium sulfate. We assessed four treatments: control, ammonium sulfate (5 mM), cadmium (100 µM CdCl2), and their combination, using fluorescence imaging, the JIP-test, and polarography. Cd stress...
Exogenous melatonin enhances drought tolerance and secondary-metabolite accumulation in Paeonia ostii 'Fengdan' in association with improved PSI-PSII photochemical coordination
L.X. ZHANG, B. ZHANG, Y.M. SUN, X.L. ZHAO, Z. WANG, Q.M. ZHANG, K.K. ZHAO, X.F. LI, X.G. HOU, Q.S. CHANG
Photosynthetica 2026, 64(3):245-257 | DOI: 10.32615/ps.2026.034
Drought limits the growth of Paeonia ostii 'Fengdan'. While melatonin (MT) is known to enhance general drought tolerance, its association with Photosystem I-Photosystem II (PSI-PSII) photochemical coordination and secondary-metabolite accumulation in P. ostii remains unclear. We foliar-sprayed potted plants under simulated drought with 0, 50, 100, 200, and 400 μmol(MT) L-1. Drought induced severe oxidative damage, impaired photosynthesis, and disrupted photochemical coordination between PSI and PSII. Among all treatments, 100 μmol(MT) L-1 proved the most effective. It coincided with reduced reactive oxygen...