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...

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...

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,...

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...

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...

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^*-...

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...

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