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),...

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...

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...

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...

LETTER TO THE EDITOR

G. GARAB

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

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...

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  

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...

LETTER TO THE EDITOR

U. SCHREIBER

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

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...