Photosynthetica, 2025 (vol. 63), issue 1
The resistance of Solanum lycopersicum photosynthetic apparatus to high-intensity blue light is determined mainly by the cryptochrome 1 content
V. KRESLAVSKI, P. PASHKOVSKIY, A. ASHIKHMIN, A. KOSOBRYUKHOV, A. SHMAREV, A. IVANOV, V. STROKINA, M. VERESHCHAGIN, G. SHIRSHIKOVA, S.I. ALLAKHVERDIEV
Photosynthetica 2025, 63(1):1-9 | DOI: 10.32615/ps.2024.043 
The effects of deficiency of cryptochrome 1 (CRY1), phytochrome B2 (phyB2) and the photoreceptor signalling DET-1 protein (hp-2 mutant) on photosynthesis and pro-/antioxidant balance in Solanum lycopersicum exposed to high-intensity blue light [HIBL, 72 h, 500/1,000 μmol(photon) m-2 s-1] were studied. Noticeable photoinhibition of photosynthesis and PSII was found in all these variants. However, the greatest decrease in photosynthesis and PSII activity was observed in the cry1 mutant. The difference among the other options was less pronounced. This low resistance of the cry1 mutant to HIBL is associated...
Sixty years of research on photosynthesis: a personal scientific autobiography
T. OGAWA
Photosynthetica 2025, 63(1):10-19 | DOI: 10.32615/ps.2025.002
The following scientific autobiography is presented here as a homage to Professor Kazuo Shibata, who is the one who led me to do research in photosynthesis. He had invited me to Riken (The Institute of Physical and Chemical Research), and had launched the Japan-US Collaboration Project on "The Solar Energy Conversion by Means of Photosynthesis" and had invited many international scientists to Riken. My research, under Shibata, started on using a sensitive method for the determination of chlorophyll b, and of SDS-PAGE for the pigment protein complexes of the two photosystems. After Shibata had passed away at the age of 66, I found post-illumination...
The story of my life into and through the science of photosynthesis: a personal perspective
J.J.S. VAN RENSEN
Photosynthetica 2025, 63(1):20-27 | DOI: 10.32615/ps.2025.001
I present here the story of my personal and scientific life. I provide information on my parents, my childhood, schooling, education at the Wageningen Agricultural University, and the work for my PhD degree on the action of some herbicides on photosynthesis under the guidance of Professor Evert Christiaan Wassink. After graduation, I obtained a position as a professor. In 1977, I spent a one-year sabbatical with Professor Govindjee at the University of Illinois at Urbana-Champaign, USA. This was the start of a long-time and successful cooperation on the effects of bicarbonate on Photosystem II. The research on the impact of herbicides on photosynthesis...
Hans Kautsky's groundbreaking discovery(ies) in 1931, its scientific environment, and the ensuing developments
U. SCHREIBER, H.K. LICHTENTHALER
Photosynthetica 2025, 63(1):28-36 | DOI: 10.32615/ps.2025.007
In 1931, Hans Kautsky discovered not only chlorophyll (Chl) fluorescence induction ("Kautsky effect") in green leaves but also metastable excited oxygen, now known as singlet oxygen, which he showed to act as an intermediate in dye-sensitized photooxidations of organic substances in vitro ("Kautsky mechanism"). While at that time practically nothing was known about the primary reactions of photosynthesis, Kautsky firmly believed that "his" mechanism is also effective in the "Chl-sensitized" conversion of light energy into chemically fixed energy. This erroneous assumption complicated the interpretation of rapid Chl fluorescence induction kinetics,...
Relative importance of chlorophyll metabolic genes for light-induced greening of potato tubers
S. TANIOS, T. THANGAVEL, A. EYLES, R.S. TEGG, C.R. WILSON
Photosynthetica 2025, 63(1):37-45 | DOI: 10.32615/ps.2025.003
Potato tuber greening occurs due to the chlorophyll accumulation upon exposure to light, however, fundamental information on tuber chlorophyll metabolism is lacking. We measured the effect of varying light exposure (0, 48, 96, and 168 h) on chlorophyll concentration and gene expression of enzymes in the chlorophyll metabolic pathway in the potato varieties that differ in greening propensity. Greening was associated with the upregulation of genes involved in chlorophyll biosynthesis, particularly glutamyl-tRNA reductase 1, magnesium-chelatase subunit H, and magnesium-protoporphyrin IX monomethyl ester cyclase, and downregulation of genes involved in...
Heat-induced F0-fluorescence rise is not an indicator of severe tissue necrosis in thermotolerance assays of young and mature leaves of a tropical tree species, Calophyllum inophyllum
K. WINTER, M. GARCIA, A. VIRGO
Photosynthetica 2025, 63(1):46-50 | DOI: 10.32615/ps.2025.004
In heating experiments with leaves, the temperature at which dark-level F0 chlorophyll a fluorescence begins to rise, Tcrit, is widely used as an indicator of photosystem II thermotolerance. However, little is known about how Tcrit correlates with irreversible leaf tissue damage. Young and mature leaves of the tropical tree species Calophyllum inophyllum were heated stepwise from 30 to 55°C, at 1°C min-1. Tcrit was 47°C in young leaves and 49°C in mature leaves. Contrary to the higher Tcrit in mature leaves, heating to 55°C elicited greater tissue damage in mature...
Response of leaf internal CO2 concentration and intrinsic water-use efficiency in Norway spruce to century-long gradual CO2 elevation
J. ©ANTRŮČEK, J. KUBÁSEK, J. JANOVÁ, H. ©ANTRŮČKOVÁ, J. ALTMAN, J. TUMAJER, M. HRÁDKOVÁ, E. CIENCIALA
Photosynthetica 2025, 63(1):51-63 | DOI: 10.32615/ps.2025.006
The strategies of Norway spruce [Picea abies (L.) Karst.] to increasing atmospheric CO2 concentration (Ca) are not entirely clear. Here, we reconstructed centennial trajectories of leaf internal CO2 concentration (Ci) and intrinsic water-use efficiency (WUEi) from the amount of 13C in tree-ring cellulose. We collected 57 cores across elevations, soil, and atmospheric conditions in central Europe. Generally, WUEi and Ci increased over the last 100 years and the Ci/Ca ratio remained almost constant....
Subtropical lichens from the Afromontane can display rapid photosynthetic acclimation to simulated climate change
N.T. NDHLOVU, T.N. KHUZWAYO, F.V. MINIBAYEVA, R.P. BECKETT
Photosynthetica 2025, 63(1):64-72 | DOI: 10.32615/ps.2025.005
Afromontane forests are an important part of the KwaZulu Natal region of southern Africa, having a distinctive flora with a high proportion of endemic species, and lichens are keystone members. Unlike other continental areas, KwaZulu Natal climate change is predicted to increase rainfall and cloudiness. In the present study, hydrated Afromontane lichens from both exposed and shaded microhabitats were given either constant [100 µmol(photon) m-2 s-1] or fluctuating [0, 200, 0 µmol(photon) m-2 s-1] light for 8 h a day for 3 d and changes monitored in nonphotochemical quenching (NPQ) and rates of...
Determination of rice (Oryza sativa L.) drought stress levels based on chlorophyll a fluorescence through independent component analysis
Q. XIA, H. TANG, J.L. TAN, S.I. ALLAKHVERDIEV, Y. GUO
Photosynthetica 2025, 63(1):73-80 | DOI: 10.32615/ps.2025.009
Sensing rice drought stress is crucial for agriculture, and chlorophyll a fluorescence (ChlF) is often used. However, existing techniques usually rely on defined feature points on the OJIP induction curve, which ignores the rich physiological information in the entire curve. Independent Component Analysis (ICA) can effectively preserve independent features, making it suitable for capturing drought-induced physiological changes. This study applies ICA and Support Vector Machine (SVM) to classify drought levels using the entire OJIP curve. The results show that the 20-dimensional ChlF features obtained by ICA provide superior classification performance,...