Photosynthetica, 2019 (vol. 57), issue 4

Exogenous calcium-induced physiological and biochemical changes in tree peony (Paeonia section Moutan DC.) under drought stress

X.Y. ZHANG, Z.W. FANG, H.N. LIU, D.Q. ZHAO, J. TAO

Photosynthetica 2019, 57(4):904-911 | DOI: 10.32615/ps.2019.108

Tree peony (Paeonia section Moutan DC.) is an excellent ornamental plant, of which Paeonia ostii (P. ostii) has a high oil value. It is widely cultivated in China, but severe drought affects its growth. In this study, the effects of exogenous calcium on drought-induced damage of P. ostii were studied. The results showed that under drought stress, leaf water content showed a downward trend, while reactive oxygen species (ROS), relative electrical conductivity (REC), proline (Pro) content, and related antioxidant enzymes increased significantly. Spraying CaCl₂ could effectively slow leaf wilting and water...

Effects of polyamines on agronomic traits and photosynthetic physiology of wheat under high temperature stress

J.G. JING, S.Y. GUO, Y.F. LI, W.H. LI

Photosynthetica 2019, 57(4):912-920 | DOI: 10.32615/ps.2019.104

Two spring wheat varieties were used to study alleviating effects of exogenous spermine (Spm) and spermidine (Spd) on agronomic traits and photosynthesis under high temperature treatment (HT). Our results showed that HT significantly decreased grain mass per panicle of heat-resistant variety (XC 6) by 25% and heat-sensitive variety (XC 31) by 32%. After HT, i.e., at 13 d after flowering, the decrease in net photosynthetic rate of XC 6 (38%) was lower than that of XC 31 (53%); the reason for this was related to XC 6, which could maintain correspondingly normal chlorophyll content (Chl), stomatal conductance (g_s), transpiration...

Photosynthesis response to severe water deficit in terminal stems of Myriolimon ferulaceum

M.À. CONESA, J. GALMÉS

Photosynthetica 2019, 57(4):921-930 | DOI: 10.32615/ps.2019.110

Myriolimon ferulaceum is a leafless species and close relative to Limonium inhabiting the same harsh environments in the rocky coast and salt marshes, with discontinuous distribution in western and central coast of the Mediterranean Basin and southern Iberian Peninsula. In order to test for the drought adaptive importance of photosynthesis in stems, and to decipher advantages and drawbacks of stem vs. leaf photosynthesis under drought conditions, M. ferulaceum was grown under the well-watered and severe water deficit conditions used in previous experiments with Limonium. Growth, stem anatomy, photosynthesis and gas exchange,...

Selenium improves the transport dynamics and energy conservation of the photosynthetic apparatus of in vitro grown Billbergia zebrina (Bromeliaceae)

A.F.C. SOUZA, J.P.R. MARTINS, A.B.P.L. GONTIJO, A.R. FALQUETO

Photosynthetica 2019, 57(4):931-941 | DOI: 10.32615/ps.2019.105

Selenium (Se) is a nonessential element to plants. However, Se is known to have a beneficial effect when present in low concentrations (Pilon-Smith et al. 2009). Several studies have demonstrated multiple impacts of Se on plant physiology, such as increased biomass production (Chen et al. 2014, Jiang et al. 2015, Feng et al. 2016), delayed senescence (Xue et al. 2001), increased tolerance to oxidative damage (Feng et al. 2013, Diao et al. 2014, Qing et al. 2015, Tang et al. 2015), increased production of carotenoid pigments (Ning et al. 2016), higher tolerance to photooxidative stresses...

Photosynthesis in reciprocal grafts of drought-tolerant and drought-sensitive cultivars of soybean under water stress

S.Y. LI, W.B. WANG, X.D. YAO, C.L. WANG, Y.Q. CAO, L.J. ZHANG, H.J. ZHANG, F.T. XIE, S.H. SONG

Photosynthetica 2019, 57(4):942-949 | DOI: 10.32615/ps.2019.109

Maintaining greater photosynthetic performance is important to improve drought resistance in soybean. However, photosynthetic response mechanisms to drought via the interaction between root and shoot remain to be clarified. Here, we investigated the roles of roots and shoots in photosynthetic responses to water stress. Grafted plants of drought-tolerant cultivar L14 and drought-sensitive cultivar L21 were grown in the pot-culture experiments. Some photosynthetic and physiological traits were measured after water-stress treatments during a podding stage. The L14 as rootstock showed a stronger growth vigor under water stress, leading to increases...

Chlorophyll fluorescence for prediction of yellow lupin (Lupinus luteus L.) and pea (Pisum sativum L.) susceptibility to drought

K. JUZOŃ, I. CZYCZYŁO-MYSZA, A. OSTROWSKA, I. MARCIŃSKA, E. SKRZYPEK

Photosynthetica 2019, 57(4):950-959 | DOI: 10.32615/ps.2019.102

Drought has become an essential environmental factor limiting plant productivity. In order to detect differences in chlorophyll (Chl) a fluorescence, Chl concentration (in SPAD units), and yield parameters of yellow lupin ('Morocco 4' and 'Taper') and pea ('Wenus' and 'SZD165'), drought stress was initiated by withholding water for 14 d (25% of field water capacity). A significant decrease of leaf relative water content was found in tested cultivars. SPAD values did not show significant changes in all cultivars. The maximum photochemical efficiency and area over the Chl a fluorescence induction curve decreased in both species under drought....

Exogenous ascorbic acid delayed leaf senescence of early flowering rice mutant FTL10

Q.L. ZHANG, W.Q. DING, Y.X. WEI, H. GAO, C.L. PENG

Photosynthetica 2019, 57(4):960-966 | DOI: 10.32615/ps.2019.113

FTL10 is an early flowering mutant of OsFTL10-suppressed transgenic rice (Oryza sativa L.) with premature senescence phenotype. Early leaf senescence can cause negative effects on rice yield, therefore delaying leaf senescence and prolonging the leaf functional stage is one of the important approaches to increase the rice yield. It is well known that ascorbic acid (AsA) is involved in regulating plant growth. To explore the effect of AsA on leaf senescence of FTL10, we treated rice leaves with 0.28 mM AsA. Results showed that total antioxidant capacity was higher and reactive oxygen species were lower in the AsA-treated group. The expression...

Effects of cadmium exposure on the growth, photosynthesis, and antioxidant defense system in two radish (Raphanus sativus L.) cultivars

J. XIN, X.H. ZHAO, Q.L. TAN, X.C. SUN, Y.Y. ZHAO, C.X. HU

Photosynthetica 2019, 57(4):967-973 | DOI: 10.32615/ps.2019.076

Radish is representative root vegetable; its edible parts are directly in contact with Cd-contaminated fields. Two radish cultivars (H4 and L19) with different resistance to Cd were selected to compare their growth, photosynthesis, and antioxidant systems. Our results revealed that H4 was more sensitive to Cd pollution than L19; a significant decrease in the biomass of H4 was observed at higher Cd concentrations. With increasing Cd concentrations, the net photosynthetic rate, effective quantum yield of PSII photochemistry, electron transport rate through PSII, and photochemical quenching were all lowered, however, reductions were more obvious in H4...

Advances in the members and biosynthesis of chlorophyll family

N.W. QIU, D.C. JIANG, X.S. WANG, B.S. WANG, F. ZHOU

Photosynthetica 2019, 57(4):974-984 | DOI: 10.32615/ps.2019.116

Chlorophylls are vital for photosynthesis, allowing plants to absorb energy from light for photosynthesis. More than one hundred species of chlorophyll have been identified. Among them, chlorophylls a, b, c (c₁, c₂, and c₃), d, and f exist in oxygenic photosynthetic organisms (e.g., higher plants, algae, and cyanobacteria), whereas anoxygenic photosynthetic bacteria possess bacteriochlorophylls a, b, c, d, e, and g. These chlorophylls have different chemical structures and properties that enable photosynthetic organisms...

Whole leaf photosynthetic light response in a carnivorous plant species Sarracenia alata

K.A. HOPKINS, D.A. GRAVATT

Photosynthetica 2019, 57(4):985-992 | DOI: 10.32615/ps.2019.119

Photosynthetic light-response curves of mature leaves of Sarracenia alata were generated and characterized using a custom built chamber (2.79 L) capable of accommodating whole leaves, or pitchers, coupled to a LI-COR 6400XT Portable Photosynthesis System. In addition to generating light-response curves, chlorophyll content, leaf area, and dry mass measurements were obtained for each pitcher. Gas-exchange variables from the light-response curves are reported on a leaf area and dry mass basis. Calculated light-saturated photosynthesis was found to be 2.09 µmol(CO₂) m^-2 s^-1 with a light-saturation...

Effect of intercropping on leaf senescence related to physiological metabolism in proso millet (Panicum miliaceum L.)

X.W. GONG, C.J. LIU, U. FERDINAND, K. DANG, G. ZHAO, P. YANG, B.L. FENG

Photosynthetica 2019, 57(4):993-1006 | DOI: 10.32615/ps.2019.112

The field experiments were conducted to explore the changes in metabolism related to leaf senescence in proso millet (Panicum miliaceum L.) under proso millet/mung bean intercropping system. Results showed that intercropping increased leaf photosynthesis, as measured by the increased net photosynthetic rate and chlorophyll content, maximum photochemical efficiency of PSII, and decreased nonphotochemical quenching coefficient. These responses resulted in the increased leaf number and area and reduced yellowing leaf rate; leaf photosynthetic capacity was maintained for longer periods. Such improvements occurred due to enhanced activities of protective...

Foliar application of selenium (Se) at heading stage induces regulation of photosynthesis, yield formation, and quality characteristics in fragrant rice

H.W. LUO, L.X. HE, B. DU, Z.M. WANG, A.X. ZHENG, R.F. LAI, X.R. TANG

Photosynthetica 2019, 57(4):1007-1014 | DOI: 10.32615/ps.2019.114

In order to study the effect of foliar application of sodium selenate on fragrant rice performance at the heading stage, the present study was conducted with two fragrant rice cultivars, 'Meixiangzhan-2' and 'Xiangyaxiangzhan'. At the heading stage, six concentrations of sodium selenate solution (0, 10, 20, 30, 40, and 50 μmol L^-1) were sprinkled to plants. Our results showed that foliar application of sodium selenate increased chlorophyll contents in rice leaves and upregulated net photosynthetic rate at the grain-filling stage. The enhancement was observed in grain yield, seed-setting rate, and in 1,000-grain mass. The highest yield...

Characterization of the ecophysiological responses of three pomegranate cultivars to salinity

A. OLMO, F. GARCIA-SANCHEZ, I. SIMON, V. LIDON, M. ALFOSEA-SIMON, J.M. CAMARA-ZAPATA, J.J. MARTINEZ-NICOLAS, S. SIMON-GRAO

Photosynthetica 2019, 57(4):1015-1024 | DOI: 10.32615/ps.2019.103

In order to understand photosynthetic responses of pomegranate plants (Punica granatum L.) to salinity, an experiment was conducted with three varieties, 'Mollar de Elche', 'Valenciana', and 'Wonderful', irrigated with seven salt concentrations (0, 40, 60, 80, 100, 120, and 140 mM NaCl). At the end of the experiment, parameters of gas exchange, chlorophyll fluorescence, water relations, and sugar and chloride concentrations were measured in leaves. As the concentration of NaCl increased, the concentration of Cl^- in leaves was elevated, and the CO₂ assimilation rate, stomatal conductance, variable fluorescence/maximum fluorescence...

Mitigation mechanism of ozone-induced reduction in net photosynthesis of Bangladeshi wheat under soil salinity stress

M.Z.U. KAMAL, M. YAMAGUCHI, Y. KINOSE, T. IZUTA

Photosynthetica 2019, 57(4):1025-1034 | DOI: 10.32615/ps.2019.115

To clarify the combined effects of O₃ and soil salinity on net photosynthetic rate, stomatal conductance, and radical scavenging system of Bangladeshi spring wheat cv. BAW1059, plants were grown in two soil salinity levels (irrigated with 0 and 150 mM NaCl solutions) and exposed to three O₃ concentrations [charcoal-filtered air (CF), 1.0-fold the ambient O₃ concentration (1.0×O₃), and 1.5-fold the ambient O₃ concentration (1.5×O₃)]. The soil salinity mitigated adverse effects of O₃ on net photosynthesis in the 7^th and flag leaves. The soil salinity did not induce...

Factors playing role in heat acclimation processes in barley and oat plants

É. DARKÓ, R. KHALIL, N. ELSAYED, M. PÁL, K.Á. HAMOW, G. SZALAI, J. TAJTI, Q.T. NGUYEN, N.T. NGUYEN, V.N. LE, T. JANDA

Photosynthetica 2019, 57(4):1035-1043 | DOI: 10.32615/ps.2019.122

In the present study, the heat acclimation processes (growing at 30/27°C for 2 weeks) in spring and winter varieties of barley (Hordeum vulgare L., varieties 'Conchita' and 'Mv Initium') and oat (Avena sativa L., varieties 'Mv Pehely' and 'Mv Hópehely') were characterized. Temperature dependence of certain chlorophyll a fluorescence induction parameters indicated the efficiency of heat acclimation. Heat treatment induced the activity of glutathinone-S-transferase, but decreased the amounts of the major polyamines. A significant increase in cadaverine content was found in 'Conchita'. 1,3-diaminopropane contents after heat acclimation...

Photosynthetic induction is slower in young leaves than in mature leaves in a tropical invader, Chromolaena odorata

S.B. ZHANG, Y.J. HAO, Q.L. DENG

Photosynthetica 2019, 57(4):1044-1052 | DOI: 10.32615/ps.2019.120

Chromolaena odorata is a noxious invasive perennial herb in tropics and subtropics throughout the world. However, photosynthetic induction of this invader is not well understood. Here, we measured the induction of gas exchange and chlorophyll fluorescence in young and mature leaves of Chromolaena odorata. During photosynthetic induction, the young leaves exhibited higher biochemical and total limitations to photosynthesis than that of the mature leaves. Photosynthetic induction in this invader was affected by a mix of biochemical and stomatal limitations. Under a strong photosynthetic photon flux density, nonphotochemical quenching was rapidly...

Epiphytic orchids Stanhopea tigrina and Prosthechea cochleata are differentially affected by drought in a subtropical cloud forest

C.I. GUEVARA-PÉREZ, P. DELGADO-SÁNCHEZ, J.A. TORRES-CASTILLO, J.D. FLORES-RIVAS, G. MENDIETA-LEIVA, E. DE LA ROSA-MANZANO

Photosynthetica 2019, 57(4):1053-1065 | DOI: 10.32615/ps.2019.123

We investigated the physiological responses of two epiphytic orchids under three light regimes of 20, 50, and 70% of total daily radiation under drought and rewatering conditions. Stanhopea tigrina was the one more affected because it exhibited strong photoinhibition and reduction of both electron transport rate and nocturnal acidity under drought and high radiation. However, this species maintained relatively high relative water content (RWC) values and underwent osmotic adjustment during the drought period and recovered photosynthetic variables during watered period. Prosthechea cochleata maintained similar water and photosynthetic...

Cotton leaf photosynthetic characteristics, biomass production, and their correlation analysis under different irrigation and phosphorus application

J.H. LI, Y.Y. WANG, N.N. LI, R.H. ZHAO, A. KHAN, J. WANG, H.H. LUO

Photosynthetica 2019, 57(4):1066-1075 | DOI: 10.32615/ps.2019.118

Water and fertilizer application are the yield improvement approaches in cotton production, especially in arid regions. We hypothesized that irrigation and phosphorus fertilization regimes would enhance cotton leaf photosynthesis capacity. We examined two irrigation levels, i.e., normal irrigation (W₁: 3,750 m³ hm^-2) and limited irrigation (W₂: 2,500 m³ hm^-2), combined with no phosphorus (P₀) and P application (P₁: applying P₂O₅ with the ratio of the fertilizer to dry soil being 0.15 g kg^-1). Leaf area (LA), net photosynthetic...

Changes in photosynthesis, chloroplast ultrastructure, and antioxidant metabolism in leaves of sorghum under waterlogging stress

R.D. ZHANG, Y.F. ZHOU, Z.X. YUE, X.F. CHEN, X. CAO, X.X. XU, Y.F. XING, B. JIANG, X.Y. AI, R.D. HUANG

Photosynthetica 2019, 57(4):1076-1083 | DOI: 10.32615/ps.2019.124

Waterlogging limits plant growth and yield. We investigated the effects of waterlogging stress on leaf photosynthesis, chlorophyll fluorescence, antioxidant capacity, chloroplast ultrastructure, and yield of sorghum (Sorghum bicolor L.). Two sorghum cultivars, Jinuoliang01 (JN01, waterlogging-tolerant cultivar) and Jinza31 (JZ31, waterlogging-sensitive cultivar) were subjected to a 12-d waterlogging treatment; the plants of the two cultivars which were not subjected to waterlogging were used as control (CK), respectively. After waterlogging treatment, the yield of JZ31 and JN01 decreased by 72.3 and 52.9%, the net photosynthetic rate of JZ31...

Yield and photochemical activity of selected rice cultivars from Eastern India under medium depth stagnant flooding

D. PANDA, A. RAY, R.K. SARKAR

Photosynthetica 2019, 57(4):1084-1093 | DOI: 10.32615/ps.2019.126

Stagnant flooding (SF) is a serious threat for rice production in rainfed lowland areas of Southeast Asian countries. To overview the SF effect, photosynthetic performances and productivity were studied with three landraces (Ravana, Kamini, and Rashpanjor) and four high-yielding cultivars (Savitri, Savitri-Sub1, Gayatri, and Varshadhan) of rice under medium depth (40-50 cm) of water level. Stagnant flooding significantly increased the stem elongation and decreased yield and yield attributing parameters. The chlorophyll a fluorescence rises from O- to P-step with distinct J- and I-step were noticed in all the cultivars up to 75 d of SF. Prolonged...

Effects of high temperature and high light on photosystem II activity in leaves of two Bauhinia species

S.B. ZHANG, Q.L. DENG, Y.J. HAO

Photosynthetica 2019, 57(4):1094-1099 | DOI: 10.32615/ps.2019.128

It is, so far, unclear whether lianas and trees differ in photosynthetic thermotolerance and response to high temperature and high light. Here, photosynthetic thermotolerance was compared in the leaves of Bauhinia brachycarpa (tree) and Bauhinia comosa (liana). Moreover, the combined treatments of four temperatures (25, 35, 40, and 45°C) and two light intensities [500 and 2,000 μmol(photon) m^-2 s^-1] were used to investigate the effects of high temperature and high light on PSII activity. The results showed that B. brachycarpa leaves exhibited higher photosynthetic thermotolerance, leaf mass per area, and...

Relative tolerance of photosystem II in spike, leaf, and stem of bread and durum wheat under desiccation

J. RANE, D. SHARMA, S. EKATPURE, L. AHER, M. KUMAR, S.V.S. PRASAD, A.N. NANKAR, N.P. SINGH

Photosynthetica 2019, 57(4):1100-1108 | DOI: 10.32615/ps.2019.111

In dryland regions, soil moisture stress often leads to desiccation and causes injury to photosynthetic machinery. Recently, chlorophyll fluorescence (ChlF)-based assessment of photosynthetic efficiency under drought stress is gaining attention due to advances in instrument development and methodology optimisation. Our study was designed to explore the use of spike photosynthetic efficiency as a trait to differentiate drought responses in wheat. Bread and durum wheat were assessed for spike, stem, and leaf tissue photosynthetic efficiency in response to progressive desiccation using ChlF imaging. Results showed that durum wheat had higher quantum efficiency...

Non-a chlorophylls in cyanobacteria

S.G. AVERINA, N.V. VELICHKO, A.A. PINEVICH, E.V. SENATSKAYA, A.V. PINEVICH

Photosynthetica 2019, 57(4):1109-1118 | DOI: 10.32615/ps.2019.130

In cyanobacteria and chloroplasts, chlorophyll a (Chl a) is not always the single type of Chl used in oxygenic photosynthesis. Rather, there is a series of non-a Chls, namely, b-type Chls, c-type Chls, Chl d, and Chl f. Plenty of reviews published over the past decades commented on these Chls in chloroplasts while only few analogously dealt with cyanobacteria. The review article takes an effort to span the gap. Cyanobacterial b-type and c-type Chls are exclusively antenna pigments; they absorb near-red and blue light, respectively, and facilitate waste-less energy input to reaction centers....

Response of the photosynthetic apparatus in the tropical fern Platycerium bifurcatum to increased ozone concentration

J. OLIWA, I. STAWOSKA, A. JANECZKO, J. OKLEŠŤKOVÁ, A. SKOCZOWSKI

Photosynthetica 2019, 57(4):1119-1129 | DOI: 10.32615/ps.2019.117

A rapid increase of ozone concentration up to the phytotoxic level is currently observed in the tropical forests. However, the effect of elevated concentration of O₃ on tropical ferns and epiphytes has not yet been described and mechanisms of tolerance remain unknown. The aim of this study was to determine the physiological response of the epiphytic fern Platycerium bifurcatum to a high concentration of ozone (150 ppb). In particular, changes in the course of photosynthesis and the pigment composition of sporotrophophyll leaves were taken into account. P. bifurcatum showed high resistance to the 4-week ozone stress. The effect...

Morphological and physiological responses of Spatholobus suberectus Dunn to nitrogen and water availability

Z.-X. ZHANG, J. ZHANG, Y. GONG, G.-Z. LIU, L.-L. GAO, P. ZHANG, C.-T. CAI

Photosynthetica 2019, 57(4):1130-1141 | DOI: 10.32615/ps.2019.125

A pot study was conducted to elucidate morphological and physiological responses of Spatholobus suberectus Dunn accessions to four nitrogen application rates (0, 10, 20, and 30 mmol L^-1) and two watering regimes (daily irrigation and irrigation every 10 d for a month). The results showed that water deficit led to marked decreases in leaf water relations and photosynthetic parameters regardless of the N treatments. Under drought conditions, the reductions in net photosynthesis occurred mainly due to stomatal factors. Although the leaf N content and stem mass ratio were positively correlated with N application, other morphological and...

Salinity variation effects on photosynthetic responses of the mangrove species Rhizophora mangle L. growing in natural habitats

D.M.S. LOPES, M.M.P. TOGNELLA, A.R. FALQUETO, M.L.G. SOARES

Photosynthetica 2019, 57(4):1142-1155 | DOI: 10.32615/ps.2019.121

This study evaluated the photosynthetic efficiency in Rhizophora mangle plants in two mangrove forests, the highest salinity (HS) area, and the lower salinity (LS) area. The CO₂ assimilation rate (P_N), stomatal conductance, leaf transpiration, intrinsic water-use efficiency, and chlorophyll a fluorescence L-band, IP-phase, and performance index were higher in the LS area. The instantaneous water-use efficiency, initial fluorescence, maximum fluorescence, and J-step were higher in the HS area. The plants growing in the HS area exhibited greater efficiency in electron transfer between the oxygen-evolving complex...

Changes in photosynthetic and chlorophyll fluorescence characteristics of sorghum under drought and waterlogging stress

F. ZHANG, K. ZHU, Y.Q. WANG, Z.P. ZHANG, F. LU, H.Q. YU, J.Q. ZOU

Photosynthetica 2019, 57(4):1156-1164 | DOI: 10.32615/ps.2019.136

Water stress is a key factor limiting sorghum growth and yield potential. This study investigated the changes in morphology, photosynthetic parameters, and fluorescence characteristics of sorghum under drought and waterlogging stress. The results indicated that these two types of water stress limited sorghum growth and led to a decrease in leaf chlorophyll (Chl), especially Chl a, which was accompanied by a decrease in net photosynthetic rate. In addition, under both types of water stress, the light-compensation point (LCP) and light-saturation point (LSP) both decreased, but the effect on these parameters was more obvious under drought. In...

Ecophysiological study of the impact of SiK^® fertilization on Castanea sativa Mill. seedling tolerance to high temperature

A. CARNEIRO-CARVALHO, R. ANJOS, A. AIRES, T. MARQUES, T. PINTO, J. GOMES-LARANJO

Photosynthetica 2019, 57(4):1165-1175 | DOI: 10.32615/ps.2019.099

The aim of this work was to evaluate the impact of Si fertilization on the resilience capacity of chestnut plants growing under high air temperatures and its recovery capacity after returning to optimal temperatures. Castanea sativa plants were supplied with 0, 5, 7.5, and 10 mM potassium silicate (SiK^®) and exposed for a month at each temperature, 25, 32, and 25°C. The results demonstrated that phytoliths were accumulated in the leaf tissues, both on the cell wall and xylem vessels, suggesting their role in the plant's tolerance to heat. Under high temperature, Si fertilization in chestnut plants increased the gas exchange and...

Chlorophyll biosynthesis and epidermal characteristics of the leaves of a variegated variety vs. all-green variety of Chlorophytum capense

Y.Q. ZHAO, L.H. DONG, B. HUANG, C.B. DING, Y.E. CHEN, Z.W. ZHANG, Y. JIANG, S. YUAN, M. YUAN

Photosynthetica 2019, 57(4):1176-1183 | DOI: 10.32615/ps.2019.129

Chlorophytum capense var. medio-pictum is widely used as a houseplant with its central yellowish white stripe in green leaves. This study investigated chlorophyll biosynthesis, and epidermal characteristics in leaf stripes of different color. The results showed that yellowish white leaf stripes (YS) have a lower 5-aminolevulinic acid (ALA) content than that of green stripes. Meanwhile, YS had higher coproporphyrinogen III (Coprogen III) and Mg-protoporphyrin monomethyl ester (Mpe) contents, but the lower content of protoporphyrinogen IX (Proto IX) and protochlorophyllide (Pchlide) compared to green stripes, suggesting that the occurrence of...

Enhancing the thermotolerance of tomato seedlings by heat shock treatment

Z.Q. YANG, C. XU, M.T. WANG, H.L. ZHAO, Y.J. ZHENG, H.J. HUANG, F. VUGUZIGA, M.A. UMUTONI

Photosynthetica 2019, 57(4):1184-1192 | DOI: 10.32615/ps.2019.127

The heat tolerance of tomato seedlings was significantly enhanced after heat shock treatment at 40°C for 4 h. Compared with the control, the heat-shocked tomato seedlings, on one hand, had a higher net photosynthetic rate (P_N), stomatal conductance, intercellular CO₂ concentration, water-use efficiency, maximal quantum yield of PSII photochemistry (F_v/F_m), electron transport rate, actual photochemical efficiency of PSII, and activity of antioxidant enzymes, on the other hand, had lower nonphotochemical quenching, relative conductivity, malondialdehyde content (MDA), and accumulation of reactive oxygen...