Photosynthetica, 2019 (vol. 57), issue 1

Smoke compounds aggravate stress inflicted on Brassica seedlings by unfavourable soil conditions

R. BĄCZEK-KWINTA, J. ANTONKIEWICZ, A. ŁOPATA-STASIAK, W. KĘPKA

Photosynthetica 2019, 57(1):1-8 | DOI: 10.32615/ps.2019.026

The aim of the study was to assess the physiological status of Brassica seedlings grown in two types of soils following a single application of smoke water (SW). One soil was contaminated with heavy metals from a local smelter, and another was sandy and poor in nutrients. Three-week monitoring indicated that soil composition was the primary factor affecting chlorophyll fluorescence (CF) parameters, growth, and development of seedlings, and the contaminants affected the plants more than the lack of nutrients. SW aggravated the negative impact of heavy metals, which became visible when the plants transiently suffered from the heavy metal exposure....

Photosynthetic and yield performance of wild barley (Hordeum vulgare ssp. spontaneum) under terminal heat stress

F. BAHRAMI, A. ARZANI, M. RAHIMMALEK

Photosynthetica 2019, 57(1):9-17 | DOI: 10.32615/ps.2019.009

Terminal heat stress is one of the major constraints of cereal production. A two-year field investigation was performed to assess the response of Hordeum vulgare ssp. spontaneum genotypes to terminal heat stress using gas-exchange parameters, photosystem efficiency, proline accumulation, cell membrane leakage, and grain yield traits. Results of analysis of variance revealed the significant effects of heat stress (E), genotype (G), and G × E on the studied traits. The results of linear regression analysis showed that yield loss was inversely correlated with the maximum quantum yield of PSII photochemistry (F_v/F_m)...

Leaf nitrogen supply improves sugarcane photosynthesis under low temperature

G. CERQUEIRA, M.C. SANTOS, P.E.R. MARCHIORI, N.M. SILVEIRA, E.C. MACHADO, R.V. RIBEIRO

Photosynthetica 2019, 57(1):18-26 | DOI: 10.32615/ps.2019.033

This study aimed to test the hypothesis that increases in leaf nitrogen concentration would reduce the sensitivity of sugarcane photosynthesis to low temperature. IACSP95-5000 plants were grown inside a growth chamber at 30/20^oC (day/night) and we evaluated the effects of leaf nitrogen spraying (2.5% urea) on plants facing low temperature (22/12°C) for eight days. The leaf nitrogen supply increased leaf nitrogen concentration and plants exhibited higher leaf gas exchange as compared to nonsprayed ones. We also found higher activity of the carboxylation enzymes, Rubisco and phosphoenolpyruvate carboxylase, as well as a higher chlorophyll...

Effects of lanthanum on the antioxidant capacity of chloroplasts and chlorophyll fluorescence parameters of maize seedlings under chromium stress

H. DAI, C. SHAN

Photosynthetica 2019, 57(1):27-31 | DOI: 10.32615/ps.2019.015

Effects of lanthanum chloride (LaCl₃) on chromium tolerance of maize were investigated at chloroplast level. The results showed that Cr stress significantly increased activities of ascorbate peroxidase, glutathione reductase, monodehydro-ascorbate reductase, dehydroascorbate reductase, superoxide dismutase, and glutathione peroxidase, nonphotochemical quenching, malondialdehyde (MDA) and hydrogen peroxide contents, but significantly reduced the ratios of reduced ascorbate to dehydroascorbate and reduced glutathione to oxidized glutathione, the contents of chlorophyll and carotenoids, maximum photochemical efficiency of PSII, photochemical...

Effect of soil salinity on growth, metal distribution and photosynthetic performance of two Lycium species

V.L. DIMITROVA, M.M. PAUNOV, V. GOLTSEV, M.P. GENEVA, Y.K. MARKOVSKA

Photosynthetica 2019, 57(1):32-39 | DOI: 10.32615/ps.2019.006

The effect of salinity on gas exchange and fluorescence characteristics in Lycium barbarum and Lycium chinense grown on nonsaline and saline soils was investigated. The distribution of Na⁺ between three types of substrates and different organs showed acropetal concentration gradient for Na⁺ accumulation only in L. barbarum grown on peat-moss-perlite and saline soil. Selective uptake of K⁺ over Na⁺ in the L. barbarum leaves was established. All plants grown on saline soil showed a slight inhibition of PSII activity as revealed by the quantum yield of the primary...

Diurnal changes in the delayed fluorescence response of an ambient light-excited green alga

W. ECKERT, F. LEUNERT, Y.Z. YACOBI, J. KÖHLER, E. KURZBAUM

Photosynthetica 2019, 57(1):40-46 | DOI: 10.32615/ps.2019.012

Delayed fluorescence (DF) is a characteristic feature of light-excited plant cells caused by the back-reaction of electrons through the electron transport chain. Targeting the response of light-adapted green algae to diurnal light changes, the present study presents novel results of DF measurements in the absence of an artificial excitation light source. Based on a linear relationship between the DF counts and light intensities from 0.15 to 0.65 W m^-2 during daybreak, we estimated an initial algal response to light intensities of 0.01 W m^-2. Dissolved oxygen concentrations began to increase at 1.0 W m^-2. A noon depression...

Characterization of Oryza nivara introgression lines: A potential prebreeding resource to improve net photosynthetic rate in elite cultivars of rice

G. HARITHA, T. VISHNUKIRAN, Y. VENKATESWARA RAO, CH. GOWTHAMI, B. DIVYA, N. SARLA, D. SUBRAHMANYAM

Photosynthetica 2019, 57(1):47-60 | DOI: 10.32615/ps.2019.003

Photosynthesis is one of the fundamental processes influencing crop growth and productivity. In order to understand better the basis of variation in net photosynthetic rate (P_N) and yield potential in rice, two backcross populations derived from Swarna × O. nivara were studied. Gas exchange and chlorophyll fluorescence measurements were taken at flowering stage and data on yield traits at harvest. P_N was significantly correlated with stomatal conductance, transpiration rate, mesophyll conductance, carboxylation efficiency, yield per plant (YLDP), and dry mass in both populations. Ten introgression lines (ILs)...

Photosystem photochemistry, prompt and delayed fluorescence, photosynthetic responses and electron flow in tobacco under drought and salt stress

K. KHATRI, M.S. RATHORE

Photosynthetica 2019, 57(1):61-74 | DOI: 10.32615/ps.2019.028

The present study aimed to understand the photosynthetic responses and chlorophyll fluorescence transient in tobacco under drought and salt stress. Net CO₂ assimilation rate, stomatal conductance, intercellular CO₂ concentration and transpiration rate decreased significantly under drought and salt stress. The maximum quantum efficiency of PSII and electron transport rate were lower in tobacco under drought and salt stress. The maximum carboxylation rate, maximum electron transport rate, triosephosphate utilization efficiency, and mesophyll conductance decreased under drought and salt stress, while dark respiration increased. A...

Leaf photosynthesis of three typical plant species affected by the subsidence cracks of coal mining: a case study in the semiarid region of Western China

Y. LIU, S.G. LEI, L.S. CHENG, W. CHENG, J.B. XIONG, Z.F. BIAN

Photosynthetica 2019, 57(1):75-85 | DOI: 10.32615/ps.2019.020

Increased attention has been paid to effects of coal mining subsidence on the growth of plants. Studying the changes of plants photosynthetic physiology under the disturbance of coal mining subsidence is the basis for understanding dynamic exchanges of plant energy and water at that mining area. The 52302 working face of the Shendong mining area was selected as the experimental site, with Artemisia ordosica, Caragana korshinskii, and Populus spp. as the research targets. Changes in leaf photosynthesis were monitored in plants at a subsidence crack area. We showed collapse cracks decreased soil moisture and caused drought stress....

Role of arbuscular mycorrhiza in alleviating the effect of cold on the photosynthesis of cucumber seedlings

J. MA, M. JANOUŠKOVÁ, L. YE, L.Q. BAI, R.R. DONG, Y. YAN, X.C. YU, Z.R. ZOU, Y.S. LI, C.X. HE

Photosynthetica 2019, 57(1):86-95 | DOI: 10.32615/ps.2019.001

Arbuscular mycorrhiza (AM) is known to enhance the rate of photosynthesis in plants, but there is little information on whether this effect is maintained at low temperature when the development of AM fungi is restrained. We therefore investigated the influence of AM on gas exchange, PSII fluorescence, and some photosynthesis-related biochemical parameters in cucumber seedlings under cold stress. Cold stress decreased, as expected, the chlorophyll content, net photosynthetic rate, and parameters related to photochemical quenching, while increasing nonphotochemical quenching and sugar contents in leaves. In contrast, AM had opposite effects on most of...

Tolerance to photoinhibition within lichen species is higher in melanised thalli

T.C. MAFOLE, K.A. SOLHAUG, F.V. MINIBAYEVA, R.P. BECKETT

Photosynthetica 2019, 57(1):96-102 | DOI: 10.32615/ps.2019.008

Some lichenized ascomycetes synthesize melanic pigments when exposed to ultraviolet light and high solar radiation. Here, we used chlorophyll fluorescence in order to test the effect of melanisation on the ability of the lichens Cetraria islandica, Lobaria pulmonaria, Peltigera aphthosa, P. membranacea, Pseudocyphellaria gilva, and Sticta sublimbata to tolerate high-light stress. For each species, melanised and pale thalli were selected from relatively exposed and shaded individuals of the same population. For all species, melanised thalli displayed significantly less photoinhibition than pale thalli following...

Photosynthesis and growth kinetics of Chlorella vulgaris R-117 cultured in an internally LED‑illuminated photobioreactor

J.R. MALAPASCUA, K. RANGLOVÁ, J. MASOJÍDEK

Photosynthetica 2019, 57(1):103-112 | DOI: 10.32615/ps.2019.031

The aim of this work was to correlate changes of photosynthesis activity vs. growth in Chlorella vulgaris R-117 (CCALA 1107), fast-growing and robust microalga cultured in an internally illuminated 10-L photobioreactor (PBR). The cultures were grown at high output irradiance provided by four LED light sources submerged in the culture when the light path was short, between 25-30 mm. The culture of Chlorella R-117 grown under 2,500 µmol(photon) m^-2 s^-1 attained a doubling time of 3.5 d and biomass density of 3.5 g(DM) L^-1 after about 10-d period. When grown under 3,500 µmol(photon) m^-2...

Coordinated changes in photosynthetic machinery performance and water relations of the xerophytic shrub Ziziphus lotus (L.) Lam. (Rhamnaceae) following soil drying

M. MARAGHNI, M. GORAI, K. STEPPE, M. NEFFATI, M.C. VAN LABEKE

Photosynthetica 2019, 57(1):113-120 | DOI: 10.32615/ps.2019.025

Aim of this study was to investigate the effect of water shortage in wild jujube plants, Ziziphus lotus (L.) Lam, and how it is related to its ecological success. All leaf anatomical traits were significantly affected following soil drying. Stressed plants displayed more negative stem water potential (ψ_w) and osmotic potential values of ca. -3.5 and -4.5 MPa, respectively, after 30 d. The relative water content declined although it still maintained high values (≥ 75%). The net photosynthetic rate, stomatal conductance, and transpiration rate were significantly inhibited as ψ_w decreased. However, the...

Osmotic adjustment, stomata morphology and function show contrasting responses to water stress in mesic and hydric grasses under elevated CO₂ concentration

S.W. MWENDIA, I.A.M. YUNUSA, B.M. SINDEL, R.D.B. WHALLEY, J.J. BRUHL

Photosynthetica 2019, 57(1):121-131 | DOI: 10.32615/ps.2019.016

The physiological response of two species of grasses with C₃ and C₄ mechanisms syndromes, Napier grass (Pennisetum purpureum Schumach × Pennisetum glaucum (L.) R. Br) and hydric common reed grass (Phragmites australis (Cav.) Trin. Ex Steud) was examined under ambient (aCO₂) and elevated CO₂ (eCO₂), in combination with water and temperature stress treatments. Under eCO₂ and subjected to water and temperature stress, the Napier grass maintained higher daytime leaf water potential (LWP) by reducing transpiration (E) and executing larger osmotic adjustment (OA)...

BRIEF COMMUNICATION
Estimation of changes in the activity of photosynthetic apparatus of plant leaves based on half-time of fluorescence intensity decrease

T.V. NESTERENKO, V.N. SHIKHOV, A.A. TIKHOMIROV

Photosynthetica 2019, 57(1):132-136 | DOI: 10.32615/ps.2019.005

The range of variations in parameter τ_0.5 - half-time of fluorescence intensity decrease during the slow phase of chlorophyll fluorescence induction (CFI) - has been studied during ontogeny of leaves of monocotyledonous and dicotyledonous plants in plant communities of different structures. Plants were grown hydroponically on expanded clay aggregate in growth chambers, under PPFD of 400 μmol(photon) m^-2 s^-1, under controlled conditions. Analysis of the literature data and results of experimental observations of τ_0.5 behavior compared to other CFI parameters, nonphotochemical quenching coefficient,...

Photosynthesis and biomass accumulation in Carapa surinamensis (Meliaceae) in response to water stress at ambient and elevated CO₂

M.F. OLIVEIRA, R.A. MARENCO

Photosynthetica 2019, 57(1):137-146 | DOI: 10.32615/ps.2019.023

Climate models predict an increase in atmospheric CO₂ concentration and prolonged droughts in some parts of the Amazon, but the effect of elevated CO₂ is still unknown. Two experiments (ambient CO₂ ‒ 400 ppm and elevated CO₂ ‒ 700 ppm) were conducted to assess the effect of drought (soil at 50% field capacity) on physiological parameters of Carapa. At ambient CO₂ concentration, light-saturated net photosynthetic rate (P_Nsat) was reduced by 33.5% and stomatal conductance (g_s) by 46.4% under drought, but the effect of drought on P_Nsat...

Different response of photosynthetic apparatus to high-light stress in sporotrophophyll and nest leaves of Platycerium bifurcatum

J. OLIWA, A. SKOCZOWSKI

Photosynthetica 2019, 57(1):147-159 | DOI: 10.32615/ps.2019.037

Tropical forest deforestation leads to sudden changes in light conditions, which is a problem for the development of epiphytes, such as Platycerium bifurcatum. High light (HL) results in disturbances of the light phase of photosynthesis and changes in leaf pigment composition. The current study determined differences in fast chlorophyll fluorescence transients and changes in radiation reflectance in sporotrophophylls and nest leaves after one and seven days of HL. In addition, a spectral range was identified with the largest change in reflectance induced by HL. Sporotrophophylls exhibited a stronger response of the photosynthetic apparatus...

Tolerance of the photosynthetic apparatus in recombinant lines of wheat adapting to water stress of varying intensity

S.V. OSIPOVA, A.V. PERMYAKOV, M.D. PERMYAKOVA, E.G. RUDIKOVSKAYA

Photosynthetica 2019, 57(1):160-169 | DOI: 10.32615/ps.2019.007

The stress tolerance index (STI) of leaf photosynthetic parameters was analysed in recombinant introgression lines of spring wheat (Triticum aestivum L.) grown under water stress of varying intensity in the simulated conditions of soil and soil-atmospheric drought. STI for the chlorophyll content was >1 regardless of experimental conditions. Carotenoids content increased only when soil drought occurred. Maximum quantum yield of PSII photochemistry was the most stable and stress-resistant parameter. Minimal fluorescence yield of the dark-adapted state was only sensitive to soil-atmospheric drought. Nonphotochemical quenching decreased under...

Chlorophyll fluorescence and initial growth of two liana species, Cuspidaria sceptrum (Cham.) L.G. Lohmann and Fridericia florida (DC) L.G. Lohmann, under changes of natural light conditions

S.M. PAULA, M.A. BOSELLI, M.C. SANCHES

Photosynthetica 2019, 57(1):170-180 | DOI: 10.32615/ps.2019.004

The physiological alterations as well as the growth were evaluated in seedlings of two liana species, Cuspidaria sceptrum and Fridericia florida, which were transferred from shade to full sunlight conditions. We cultivated one group of seedlings under full sunlight, the second group under natural shade beneath canopy, and the third group was transferred from shade to full sunlight. Reductions on the potential quantum yield of PSII (F_v/F_m) during predawn was detected under full sunlight, but these responses were more pronounced when the plants were transferred from shade to full sunlight. C. cuspidaria...

Brassinosteroids increase electron transport and photosynthesis in soybean plants under water deficit

Y.C. PEREIRA, W.S. RODRIGUES, E.J.A. LIMA, L.R. SANTOS, M.H.L. SILVA, A.K.S. LOBATO

Photosynthetica 2019, 57(1):181-191 | DOI: 10.32615/ps.2019.029

Drought frequently results in significant losses in agricultural systems, including the soybean yield. Brassinosteroids exhibit multiple actions on essential processes, including chlorophyll fluorescence and gas exchange. Considering that the electron transport rate (ETR) into photosystems can exercise interference on net photosynthetic rate (P_N), this research aims to determine whether 24-epibrassinolide (EBR) affects electron transport and find out if there is any repercussion on photosynthesis in soybean plants affected by the water deficit. The experiment was performed using a randomized factorial design, with two water conditions...

Changes in foliar epicuticular wax and photosynthesis metabolism in evergreen woody species under different soil water availability

S. PEREIRA, K. FIGUEIREDO-LIMA, A.F. M. OLIVEIRA, M.G. SANTOS

Photosynthetica 2019, 57(1):192-201 | DOI: 10.32615/ps.2019.013

Epicuticular waxes (EW) are important for plant physiology as a protective barrier against water loss. Thus, the main goal of this study was to evaluate the ecophysiological performance of Cynophalla flexuosa, an evergreen woody species, under different foliar EW contents. The study was conducted during three periods throughout the year in a seasonally dry tropical forest area. The xylem water potential decreased to 70% at midday. The main EW components were n-alkane chains, effective in keeping the cuticle impermeability. We analyzed intact leaves and leaves with EW removed. C. flexuosa did not alter its photosynthetic...

Leaf rolling as indicator of water stress in Cistus incanus from different provenances

G. PUGLIELLI, L. GRATANI, L. VARONE

Photosynthetica 2019, 57(1):202-208 | DOI: 10.32615/ps.2019.014

Leaf movements such as leaf rolling affect plant physiological performance by reducing light capture. The relationship between leaf rolling and physiological traits under imposed water stress conditions was analyzed in two population of Cistus incanus. We tested the hypothesis that leaf rolling reflected physiological changes occurring during water stress irrespective of the different acclimation in order to cope with water stress. On the whole, our results confirmed our hypothesis since leaf rolling significantly reflected physiological activity changes. Moreover, leaf rolling might be involved in protecting the PSII complex under water...

Phytotoxic effect of silver nanoparticles in Triticum aestivum: Improper regulation of photosystem I activity as the reason for oxidative damage in the chloroplast

A. RASTOGI, M. ZIVCAK, D.K. TRIPATHI, S. YADAV, H.M. KALAJI

Photosynthetica 2019, 57(1):209-216 | DOI: 10.32615/ps.2019.019

Silver nanoparticles (AgNPs) are used in several industries and their continuous release into environment can damage the ecosystem. Our study observed the impact of two concentrations of AgNPs (1 and 5 mM) on wheat seedlings. In this study, the treatment of AgNPs was found to have a significant impact on growth parameters, such as root and shoot length of wheat seedlings, in addition to that biochemical parameters, such as activity of catalase, glutathione, flavonoid, and chlorophyll concentrations, were also affected. AgNPs apparently suppressed the photosynthetic activity of the seedlings, with a clear destruction of photosystems at 5 mM concentration....

Morphological, anatomical and physiological traits of Euryodendron excelsum as affected by conservation translocation (augmentation vs. conservation introduction) in South China

H. REN, H.L. YI, Q.M. ZHANG, J. WANG, X.Y. WEN, Q.F. GUO, H. LIU

Photosynthetica 2019, 57(1):217-225 | DOI: 10.32615/ps.2019.024

Euryodendron excelsum is a rare and endangered evergreen tree in South China. We conducted two experimental translocations (augmentation and conservation introduction) on this species and assessed morphological, anatomical and physiological traits of leaves after translocation. The introduction plants showed smaller specific leaf area, less developed palisade tissues, smaller palisade/spongy tissue ratio, stomata density and anthocyanin content, lower values of maximal quantum yield of PSII photochemistry, photochemical quenching coefficient, net photosynthetic rate, light-saturated net photosynthetic rate, light-saturation point, but higher light-compensation...

Machine learning in determination of water saturation deficit in wheat leaves on basis of Chl a fluorescence parameters

K. RYBKA, M. JANASZEK-MAŃKOWSKA, P. SIEDLARZ, D. MAŃKOWSKI

Photosynthetica 2019, 57(1):226-230 | DOI: 10.32615/ps.2019.017

Water saturation deficit (WSD) is a parameter commonly used for detection of plant tolerance to temporary water shortages. However, this parameter does not meet criteria set for screening. On the other hand, measurement of chlorophyll (Chl) a fluorescence is a fast and high-throughput method. This work presents the application of learning systems to set up a model between WSD and Chl a fluorescence parameters allowed for development of a new screening test. Multilayer perceptron (MLP) was trained to predict WSD values on the basis of Chl a fluorescence. The best MLP consisted of three inputs: maximal quantum yield of PSII photochemistry,...

Activation state of Rubisco decreases with the nitrogen accumulation during the reproductive stage in soybean [Glycine max (L.) Merr.]

K. SAKODA, S. SUZUKI, H. FUKAYAMA, Y. TANAKA, T. SHIRAIWA

Photosynthetica 2019, 57(1):231-236 | DOI: 10.32615/ps.2019.002

The CO₂ assimilation rate, N content, Rubisco activation state, and protein distribution to Rubisco and Rubisco activase in the leaf were analyzed for four soybean genotypes at two growth stages under field conditions. The CO₂ assimilation rate was largely constant except for one genotype during the reproductive stage. Rubisco activation state significantly decreased with the increase of N content during this period in three of four genotypes. When standardized by total soluble protein amount, Rubisco activase amount was constant during this period in three genotypes. The results in the present study showed the deactivation of...

Genotypic differences in leaf gas exchange and growth responses to deficit irrigation in reticulatus and inodorus melons (Cucumis melo L.)

S.P. SHARMA, D.I. LESKOVAR, K.M. CROSBY

Photosynthetica 2019, 57(1):237-247 | DOI: 10.32615/ps.2019.022

Leaf gas exchange and growth responses of three melon cultivars, i.e., Mission, Da Vinci (var. reticulatus), and Super Nectar (var. inodorus) to two irrigation regimes, 50 and 100% crop evapotranspiration (ETc) were investigated under water-limited conditions of southwest Texas. In 2012, deficit irrigation (50% ETc) significantly decreased above-ground biomass, leaf area, leaf number, and specific leaf area, while leaf gas exchange, relative water content, water potential, chlorophyll fluorescence (F_v/F_m), and chlorophyll content (SPAD index) were not affected. However, in the drier year 2011, deficit irrigation...

Interactive effects of temperature and phosphorus nutrition on soybean: leaf photosynthesis, chlorophyll fluorescence, and nutrient efficiency

S.K. SINGH, V.R. REDDY, D.H. FLEISHER, D.J. TIMLIN

Photosynthetica 2019, 57(1):248-257 | DOI: 10.32615/ps.2019.036

An experiment was conducted to assess interactive effects of temperature (22, 26, 30, and 34°C daily mean T) and phosphorus (P) fertilization (sufficient, 0.5 mM, and deficient, 0.08 mM P) on soybean physiological traits. The P deficiency decreased leaf P concentration over approximately 50% across temperature regimes. However, a marked decrease in physiological traits under P deficiency was primarily observed below and at optimum temperature (26°C) but not at warmer temperatures. This resulted in a significant P × T interaction for parameters such as net photosynthetic rate (P_N), stomatal conductance, quantum yield of PSII (Φ_PSII),...

Allocation pattern, photosynthetic performance and sugar metabolism in hydroponically grown seedlings of loquat (Eriobotrya japonica Lindl.) subjected to salinity

M.-I.N. SOTIRAS, I.E. PAPADAKIS, M. LANDI, G. TSANIKLIDIS, P.I. TSIANTAS, M. PSYCHOYOU

Photosynthetica 2019, 57(1):258-267 | DOI: 10.32615/ps.2019.018

Hydroponically grown loquat seedlings were subjected to increasing NaCl concentrations (0, 12, 24, and 48 mM) for 42 d. At the whole plant level, Na⁺ and Cl^- accumulated proportionally to the salt treatments; however, Na⁺ accumulated prevalently in leaves whilst Cl^- accumulated prevalently in stems. Reduction of leaf biomass was only observed in seedlings grown with 48 mM NaCl, whereas net photosynthesis declined along with increasing NaCl concentration and salinity led to general accumulation of glucose, reduction of mannitol and sorbitol, and changes in pigment composition in loquat leaves. Increasing level...

Diurnal and seasonal variations in the photosynthetic performance and chlorophyll fluorescence of cassava 'Rayong 9' under irrigated and rainfed conditions

K. VONGCHAROEN, S. SANTANOO, P. BANTERNG, S. JOGLOY, N. VORASOOT, P. THEERAKULPISUT

Photosynthetica 2019, 57(1):268-285 | DOI: 10.32615/ps.2019.027

Diurnal photosynthesis responses of cassava cultivar Rayong 9 ('RY9') three months after planting, grown in a field conditions under irrigated and rainfed conditions, were evaluated during the rainy, cool, and hot seasons. Under the mild conditions of the rainy and cool seasons, net photosynthetic rates (P_N) increased in parallel with light intensity and attained the maximum at 13.00 or 11.00 h. In the hot season, P_N attained the prominent peak at 9.00 h, after which stomatal conductance decreased rapidly coordinated with declining P_N and nonphotochemical quenching was enhanced. Photosynthetically...

Effects of exogenous glucose and sucrose on photosynthesis in triticale seedlings under salt stress

L.H. WANG, G.L. LI, S. WEI, L. J. LI, S.Y. ZUO, X. LIU, W.R. GU, J. LI

Photosynthetica 2019, 57(1):286-294 | DOI: 10.32615/ps.2019.030

Salinization disturbs metabolic processes of plants and results in reduced growth and productivity. In our study, the Dongnong 8809 variety of triticale (×Triticosecale Wittmack) was evaluated for its physiological responses to salt stress during the seedling stage. We evaluated biomass production, relative chlorophyll content, chlorophyll fluorescence, and leaf gas-exchange parameters. Our results indicated that salt stress greatly reduced matter accumulation, SPAD value, photosynthetic capacity. However, seedlings treated with exogenous sugars showed significantly enhanced matter accumulation, SPAD value, quantum yield of PSII, electron transport...

The nutritional status and fluorescence characteristics of maize cultivars with different chlorophyll content and yields

Y. WANG, Z.C. AN, R.K. Li, X. YANG, Y.F. HUANG, R.X. SHAO, Y.L. YE

Photosynthetica 2019, 57(1):295-302 | DOI: 10.32615/ps.2019.032

Chlorophyll (Chl) is generally positively related to corn grain yields; however, light-leaf-colored maize may also achieve high yields. Thus, Chl is seemingly not a key parameter for maize producers. Modern maize cultivars (55) were divided into four types, based on grain yields and ear leaf SPAD readings. The results revealed that there was no correlation between the SPAD readings and corn grain yields across different maize cultivars. High-yield maize possessed higher nitrogen, phosphorus, and potassium accumulation and utilization compared to that of low-yield maize; the N-transport efficiency of low yield and high SPAD was the lowest among various...

Shading of mature leaves systemically regulates photosynthesis and leaf area of new developing leaves via hormones

Y.S. WU, W.Z. GONG, Y.M. WANG, W.Y. YANG

Photosynthetica 2019, 57(1):303-310 | DOI: 10.32615/ps.2019.021

In order to explore whether leaf area of developing leaves was regulated by systemic irradiance signal from mature leaves, we investigated the leaf area, leaf anatomy, photosynthesis, auxin, gibberellin, and cytokinin contents of new developing leaves in soybean growing under conditions of shaded mature leaves (MS), shaded whole plants (WS), and under full sunlight (NS). The results showed that developing leaves under MS exhibited the higher leaf area and leaf mass than that of WS. Blade thickness, palisade tissue thickness, sponge tissue thickness, cell size, cell numbers, net photosynthetic rate, stomatal conductance, transpiration rate, and cytokinin...

Intraspecific variation in photosynthetic nitrogen-use efficiency is positively related to photosynthetic rate in rice (Oryza sativa L.) plants

M. YE, S.B. PENG, Y. LI

Photosynthetica 2019, 57(1):311-319 | DOI: 10.32615/ps.2019.011

To explore the natural variation in leaf photosynthesis and investigate its relations with leaf nitrogen (N) status, 121 rice cultivars were pot-grown and their leaf photosynthetic rate (P_N) and N content were measured on the flag leaves at heading stage before anthesis. The results showed that there were substantial natural variations in P_N, leaf N content based on leaf area and leaf mass, and photosynthetic N-use efficiency (PNUE). P_N ranged between 15.4 and 32.6 μmol m^-2 s^-1; P_N and PNUE of four widely grown cultivars in China were significantly lower...

Transcriptome analysis revealed the effect of a combination of red and blue LEDs on photosynthesis, chlorophyll and carotenoid biosynthesis in Brassica campestris L.

T. ZHANG, Y.Y. SHI, F.Z. PIAO, N.S. DU, Z.Q. SUN

Photosynthetica 2019, 57(1):320-331 | DOI: 10.32615/ps.2019.034

Here, we analyzed the transcriptomes of Brassica campestris L. ssp. chinensis Makino under the treatment of a combination of red (R) and blue (B) light. In total, 5,643 differentially expressed genes (DEGs) were found under the R and B combination compared with the white light. An analysis of the DEGs enriched in photosynthesis and antenna proteins showed that there were many more upregulated subunits in PSII than those in PSI. The DEGs encoding the cytochrome b₆f complex, photosynthetic electron transport, ATP synthases, and key genes involved in chlorophyll (Chl) and carotenoids (Car) biosynthesis were also...

Identification of a GLDH-overexpressing Arabidopsis mutant and its responses to high-light stress

X.T. ZHENG, X.H. ZHANG, Y.Z. WANG, M.L. CAI, M. LI, T.J. ZHANG, C.L. PENG

Photosynthetica 2019, 57(1):332-341 | DOI: 10.32615/ps.2019.038

Ascorbic acid (AsA) is an important antioxidant protecting plant against environmental stresses. L-galactono-1,4-lactone dehydrogenase (GLDH) is a key enzyme in AsA synthesis pathway. To investigate the roles of AsA in mitigating high light (HL) damage, Arabidopsis GLDH mutants SALK_060087 and SALK_008236 with altered GLDH-expression were screened for homozygotes. No homozygotes were identified from SALK_060087, but most individuals of the SALK_008236 line (GLDH-236OE) were GLDH-overexpressing homozygous mutants accumulating more AsA than wild type (WT). An investigation of the physiological responses to HL demonstrated...

Comprehensive effects of exogenous salicylic acid and light on chlorophyll fluorescence parameters and photosynthetic oxygen evolution in Ulva prolifera

P.L. ZHUO, Y.H. LI, J.L. ZHONG, M.S. ZHENG, W.R. ZHU, N.J. XU

Photosynthetica 2019, 57(1):342-349 | DOI: 10.32615/ps.2019.035

Ulva prolifera is one of the causative species of green tides. Salicylic acid (SA) alleviated the high-temperature damage by up-regulating a portion of antioxidant-related proteins, however, little is understood regarding the impacts of SA under high light in this species. In order to study the regulation effects of SA on U. prolifera under different light conditions, we grew this species under three SA concentrations (0, 2.5, 5.0 µg mL^-1) and three light levels [high light (HL): 400 μmol(photon) m^-2 s^-1, medium light (ML): 160 μmol(photon) m^-2 s^-1, and low light (LL): 70 μmol(photon)...

Photosynthetic capacity, osmotic adjustment and antioxidant system in sugar beet (Beta vulgaris L.) in response to alkaline stress

C.L. ZOU, Y.B. WANG, L. LIU, D. LIU, P.R. WU, F.F. YANG, B. WANG, T. TONG, X.M. LIU, C.F. LI

Photosynthetica 2019, 57(1):350-360 | DOI: 10.32615/ps.2019.010

Photosynthetic characteristics of sugar beet cultivars KWS0143 and Beta464 were studied under alkaline conditions, including 0 (A₀, control), 25 (A₁), 50 (A₂), 75 (A₃), and 100 mM of mixed alkali (Na₂CO3:NaHCO3, 1:2). A₂, A₃, and A₄ reduced net photosynthetic rate (P_N), stomatal conductance, and transpiration rate, but rose intercellular CO₂ concentration. Reduction in P_N occurred probably due to nonstomatal limitation. The decrease in efficiency of photosynthetic electron transport might be the main reason for the...

Editorial

Editorial 2019

Helena Synková

Photosynthetica 2019, 57(1):i

At the end of 2018, Photosynthetica was pressed to close one period of its existence under wings of the international giant, Springer Nature, which had arranged our distribution since 1997. Starting January 2019, Photosynthetica has become an open-access journal with our old, but ever present publisher, Institute of Experimental Botany, ASCR, Prague. We had to switch also from our previous online peer-review system, ScholarOne, into the new one, Actavia.