Combining Gas Exchange and Chlorophyll Fluorescence to Assess the Adaptability of Medicinal Plant Aesculus chinensis Compared to Two Imported Aesculus Species

2013 ◽  
Vol 726-731 ◽  
pp. 4330-4336
Author(s):  
Hai Yan Fu ◽  
Fu Qiang Song ◽  
Jia Sen Wu ◽  
Xiang Shi Kong ◽  
Dan Dan Qi
Keyword(s):  
Chlorophyll Fluorescence ◽  
Electron Transport ◽  
Gas Exchange ◽  
Tree Species ◽  
Light Energy ◽  
The Other ◽  
Photochemical Quenching ◽  
Chlorophyll Fluorescence Parameters ◽  
Psii Photochemistry

Analysis of gas exchange and determination of chlorophyll fluorescence parameters in leaves of three tree species including Aesculus chinensis, A. octandra and A. hybrida were conducted under field conditions and then comparison was carried out. The results showed that the light compensation point (LCP) was significantly different among the three tree species, of which the LCP of A. chinensis with 12.53 μmol·m-2·s-1 that of the lowest was notable lower than that of the other two species (36.11 and 46.41 μmol·m-2·s-1respectively). On the other hand, the light saturation point (LSP) of the three tree species also showed remarked different and the LSP of A. chinensis was 1475 μmol·m-2·s-1 which was dramatic higher than that of the other two species respective to 1366.67 and 1025 μmol·m-2·s-1. Beside, the maximum net photosynthetic rate (MNPR) was different too, MNPR of A. chinensis was 9.47μmol CO 2·m-2·s-1which was higher than the other two species (5.91 and 2.30 μmol CO 2·m-2·s-1 respectively), indicating A. chinensis had a higher photosynthetic capacity and stronger utilization ability for light energy. Moreover, the electron transport rate (ETR) of A. chinensis was higher than A. octandra and A. hybrida, the ETR of the former was 55.800 that were 1.33 and 1.44 times of the later two respectively. Quantum yield of PSII photochemistry (ФPSII) in A. chinensis was higher than A. octandra and A. hybrida, the ФPSII of the former was 0.470 that were 1.21 and 1.15 times of the later two respectively. Furthermore, the photochemical quenching (qP) of A. chinensis was 0.975 much higher than A. octandra and A. hybrida respective to 1.10 and 1.10 times of the later two respectively. These three photochemical parameters with dramatic different among the three different tree species suggested A. chinensis had a high activity of electron transport and conversion efficiency for light energy.

scholarly journals Chlorophyll fluorescence response of wheat to exogenous application of growth regulators under terminal drought stress

2015 ◽  
Vol 70 (1) ◽  
pp. 13
Author(s):  
Hamid Mohammadi ◽  
Mohsen Janmohammadi ◽  
Naser Sabaghnia
Keyword(s):  
Chlorophyll Fluorescence ◽  
Drought Stress ◽  
Electron Transport ◽  
Quantum Yield ◽  
Photochemical Quenching ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters ◽  
Exogenous Application ◽  
Terminal Drought ◽  
Terminal Drought Stress

<p>Drought stress negatively affects plant photosynthesis and disturbs the electron transport activity. Evaluation of the chlorophyll fluorescence parameters might reflect influence of the environmental stress on plants and can be applied as an indicator of the primary photochemistry of photosynthesis. In current study the effect of foliar application of benzylaminopurine (BAP, a synthetic cytokinin) and abscisic acid (ABA) on chlorophyll fluorescence parameters of relatively drought tolerant (Pishtaz) and susceptible (Karaj3) bread wheat genotypes under well watered and terminal water deficit condition have been evaluated. Terminal drought was induced by withholding water at anthesis stage (Zadoks scale 65). Results showed that coefficient of non-photochemical quenching of variable fluorescence (qN), quantum yield of PS II photochemistry (ΦPSII) and photochemical quenching (qP) were affected by hormone spray treatments. So that evaluation of parameters at 7 day after foliar treatments revealed that ABA significantly increased electron transport rate (ETR) and qN while considerably decreased ΦPSII, gs and maximum quantum yield of photosystem II (Fv/Fm). However exogenous application of cytokinin could increase gs, Fv/Fm and ΦPSII and the highest value of these parameters was recorded in <em>cytokinin </em>treated plants of Pishtaze cv. under well watered condition. Nevertheless, evaluation of the parameters in different periods after spraying showed that with approaching the maturity stage some traits like as gs, Fv/Fm and ETR significantly decreased in both genotypes. Evaluation of gs and Chlorophyll fluorescence parameters of genotypes between different irrigation levels showed that although cv. Pishtaz showed higher performance of PSII under well watered condition, it failed to maintain its superiority under stress condition. This finding suggests that some more responsive parameter like gs, Fv/Fm and ΦPSII can be considered as reliable indicator for understanding the biochemical and physiological effects of exogenous application of phytohormones under terminal drought stress.</p>

scholarly journals Effects of nitrogen supply level on photosynthesis and chlorophyll fluorescence characteristics of rice under salt stress

2019 ◽  
pp. 741
Author(s):  
Chen Xu ◽  
Qian Li ◽  
Xiaolong Liu ◽  
Hongjun Wang ◽  
Fenglou Ling
Keyword(s):  
Salt Stress ◽  
Chlorophyll Fluorescence ◽  
Photochemical Quenching ◽  
Effective Quantum Yield ◽  
Plasma Membrane Permeability ◽  
Chlorophyll Fluorescence Parameters ◽  
Nitrogen Levels ◽  
Fluorescence Characteristics ◽  
Psii Photochemistry ◽  
Lower Magnitude

The change of photosynthesis and chlorophyll fluorescence parameters of rice were studied in five nitrogen levels during tillering, booting, and heading periods under salt stress. The net photosynthetic rate (PN), stomatal conductance (gs), transpiration rate (E), apparent mesophyll conductance (AMC), effective quantum yield of PSII photochemistry (ΦPSII), electron transport rate (ETR), and photochemical quenching coefficient (qP) were significantly declined under salt stress and exhibited a lower magnitude of decline in the 2N, 1N, and 1/2N treatments respectively during tillering, booting, and heading periods. The stomatal limit value (Ls), Nonphotochemical quenching (NPQ) and plasma membrane permeability were significantly increased and exhibited a lower magnitude of increase in the 2N, 1N, and 1/2N treatments respectively during tillering, booting, and heading periods. The amount of nitrogen in the nutrient solution should be reduced 50% after the heading period to decrease salt damage to rice under salt stress.

scholarly journals Spectral Composition of Light Affects Sensitivity to UV-B and Photoinhibition in Cucumber

2021 ◽  
Vol 11 ◽  
Author(s):  
Carolina Falcato Fialho Palma ◽  
Victor Castro-Alves ◽  
Luis Orlando Morales ◽  
Eva Rosenqvist ◽  
Carl-Otto Ottosen ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Light Intensity ◽  
Leaf Gas Exchange ◽  
Red Light ◽  
Broad Band ◽  
Green Light ◽  
Light Conditions ◽  
Chlorophyll Fluorescence Parameters ◽  
Psii Photochemistry

Ultraviolet B (UV-B) (280–315 nm) and ultraviolet A (UV-A) (315–400 nm) radiation comprise small portions of the solar radiation but regulate many aspects of plant development, physiology and metabolism. Until now, how plants respond to UV-B in the presence of different light qualities is poorly understood. This study aimed to assess the effects of a low UV-B dose (0.912 ± 0.074 kJ m–2 day–1, at a 6 h daily UV exposure) in combination with four light treatments (blue, green, red and broadband white at 210 μmol m–2 s–1 Photosynthetically active radiation [PAR]) on morphological and physiological responses of cucumber (Cucumis sativus cv. “Lausanna RZ F1”). We explored the effects of light quality backgrounds on plant morphology, leaf gas exchange, chlorophyll fluorescence, epidermal pigment accumulation, and on acclimation ability to saturating light intensity. Our results showed that supplementary UV-B significantly decreased biomass accumulation in the presence of broad band white, blue and green light, but not under red light. UV-B also reduced the photosynthetic efficiency of CO2 fixation (α) when combined with blue light. These plants, despite showing high accumulation of anthocyanins, were unable to cope with saturating light conditions. No significant effects of UV-B in combination with green light were observed for gas exchange and chlorophyll fluorescence parameters, but supplementary UV-B significantly increased chlorophyll and flavonol contents in the leaf epidermis. Plants grown under red light and UV-B significantly increased maximum photosynthetic rate and dark respiration compared to pure red light. Additionally, red and UV-B treated plants exposed to saturating light intensity showed higher quantum yield of photosystem II (PSII), fraction of open PSII centres and electron transport rate and showed no effect on the apparent maximum quantum efficiency of PSII photochemistry (Fv/Fm) or non-photochemical quenching, in contrast to solely red-light conditions. These findings provide new insights into how plants respond to UV-B radiation in the presence of different light spectra.

Different strategies of acclimation of photosynthesis, electron transport and antioxidative activity in leaves of two cotton species to water deficit

2016 ◽  
Vol 43 (5) ◽  
pp. 448 ◽  
Author(s):  
Xiao-Ping Yi ◽  
Ya-Li Zhang ◽  
He-Sheng Yao ◽  
Hong-Hai Luo ◽  
Ling Gou ◽  
...  
Keyword(s):  
Electron Transport ◽  
Water Deficit ◽  
Heat Dissipation ◽  
Photosynthetic Apparatus ◽  
Light Energy ◽  
Photochemical Quenching ◽  
Antioxidant Systems ◽  
Mehler Reaction ◽  
Cotton Species ◽  
Excess Light

To better understand the adaptation mechanisms of the photosynthetic apparatus of cotton plants to water deficit conditions, the influence of water deficit on photosynthesis, chlorophyll a fluorescence and the activities of antioxidant systems were determined simultaneously in Gossypium hirsutum L. cv. Xinluzao 45 (upland cotton) and Gossypium barbadense L. cv. Xinhai 21 (pima cotton). Water deficit decreased photosynthesis in both cotton species, but did not decrease chlorophyll content or induce any sustained photoinhibition in either cotton species. Water deficit increased ETR/4 − AG, where ETR/4 estimates the linear photosynthetic electron flux and AG is the gross rate of carbon assimilation. The increase in ETR/4 − AG, which represents an increase in photorespiration and alternative electron fluxes, was particularly pronounced in Xinluzao 45. In Xinluzao 45, water deficit increased the activities of antioxidative enzymes, as well as the contents of reactive oxygen species (ROS), which are related to the Mehler reaction. In contrast, moderate water deficit particularly increased non-photochemical quenching (NPQ) in Xinhai 21. Our results suggest that Xinluzao 45 relied on enhanced electron transport such as photorespiration and the Mehler reaction to dissipate excess light energy under mild and moderate water deficit. Xinhai 21 used enhanced photorespiration for light energy utilisation under mild water deficit but, when subjected to moderate water deficit, possessed a high capacity for dissipating excess light energy via heat dissipation.

Xanthophyll cycle, light energy dissipation and photosystem II down-regulation in senescent leaves of wheat plants grown in the field

2001 ◽  
Vol 28 (10) ◽  
pp. 1023 ◽  
Author(s):  
Congming Lu ◽  
Qingtao Lu ◽  
Jianhua Zhang ◽  
Qide Zhang ◽  
Tingyun Kuang
Keyword(s):  
Energy Dissipation ◽  
Photosystem Ii ◽  
Excitation Energy ◽  
Xanthophyll Cycle ◽  
Light Energy ◽  
Photochemical Quenching ◽  
Down Regulation ◽  
Psii Efficiency ◽  
Psii Photochemistry ◽  
Assimilation Capacity

Photosynthesis, the xanthophyll cycle, light energy dissipation and down-regulation of photosystem II (PSII) in senescent leaves of wheat plants grown in the field were investigated. With the progress of senescence, maximal efficiency of PSII photochemistry decreased only slightly early in the morning but substantially at midday. Actual PSII efficiency, photochemical quenching, efficiency of excitation capture by open PSII centres, and the I–P phase of fluorescence induction curves decreased significantly and such decreases were much more evident at midday than in the morning. At the same time, non-photochemical quenching, thermal dissipation and de-epoxidation status of the xanthophyll cycle increased, with much greater increases at midday than in the morning. These results suggest that the xanthophyll cycle played a role in photoprotection of PSII in senescent leaves by dissipating excess excitation energy. Taking into account the substantial decrease in photosynthetic capacity in senescent leaves, our data seem to support the view that the decrease in actual PSII efficiency in senescent leaves may represent a mechanism to down-regulate photosynthetic electron transport to match the decreased CO2 assimilation capacity and avoid photodamage of PSII from excess excitation energy.

scholarly journals Waterlogging tolerance evaluation of fifteen poplar clones cultivated in the Jianghan Plain of China

2021 ◽  
Vol 49 (3) ◽  
pp. 12421
Author(s):  
Ruonan GENG ◽  
Xinye ZHANG ◽  
Xiaoping FAN ◽  
Qian HU ◽  
Tianhong NI ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Survival Rates ◽  
Biomass Accumulation ◽  
Co2 Concentration ◽  
Jianghan Plain ◽  
Waterlogging Tolerance ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters

To provide references for poplar cultivation in waterlogged prone area of Jianghan Plain of China, the waterlogging tolerance of 15 poplar clones widely cultivated in these areas were evaluated based on their responses to 45-day waterlogging stress followed by 15-day drainage recovery in morphology, growth, biomass accumulation, leaf gas exchange and chlorophyll fluorescence parameters. The results showed that the normal watered seedlings (CK) of the 15 clones grew vigorously during the experiment, and no defoliation and death occurred. For the seedlings under waterlogging treatment (water 10 cm above the soil surface), its morphology changed markedly, including slowing growth, chlorosis and abscission of leaves, development of hypertrophied lenticels and adventitious roots etc. Waterlogging stress significantly inhibited the seedling growth of height and ground diameter, biomass accumulation, as well as leaf gas exchange and chlorophyll fluorescence parameters of the 15 clones with varying degrees. The net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), intercellular CO2 concentration/ environmental CO2 concentration (Ci/Ca), variable fluorescence (Fv), variable fluorescence/ initial fluorescence (Fv/Fo) and PS Ⅱ primary light energy conversion efficiency (Fv/Fm) decreased gradually with the prolonged waterlogging, and reached their bottom on day 45. During the terminal recovery stage, the leaf gas exchange and chlorophyll fluorescence parameters of the most clones increased, but their recovery abilities were significantly different. At the end of the experiment, the highest survival rates (100%) were observed in DHY, HS-1, HS-2, I-72, I-69, I-63 and NL-895, and the lowest (zero) occurred in XYY. Survival rates of the other clones ranged from 33.33% to 83.33%. Both results of cluster analysis and membership function analysis showed that HS-1, I-69, DHY, NL-895 and HS-2 had the strongest waterlogging tolerance, XYY and HBY were the worst, and the other clones were moderate. These results would provide guidance not only for the selection of cultivated varieties in Jianghan Plain, but also for the selection of hybrid parents for waterlogging resistance breeding.

scholarly journals Effect of Drought Stress on Chlorophyll Fluorescence Parameters, Phytochemical Contents, and Antioxidant Activities in Lettuce Seedlings

Horticulturae ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 238
Author(s):  
Yu Kyeong Shin ◽  
Shiva Ram Bhandari ◽  
Jung Su Jo ◽  
Jae Woo Song ◽  
Jun Gu Lee
Keyword(s):  
Ascorbic Acid ◽  
Chlorophyll Fluorescence ◽  
Drought Stress ◽  
Quantum Yield ◽  
Antioxidant Activities ◽  
Growth Parameters ◽  
Photochemical Quenching ◽  
Total Phenol Content ◽  
Effective Quantum Yield ◽  
Chlorophyll Fluorescence Parameters

This study monitored changes in chlorophyll fluorescence (CF), growth parameters, soil moisture content, phytochemical content (proline, ascorbic acid, chlorophyll, total phenol content (TPC), and total flavonoid content (TFC)), and antioxidant activities in 12-day-old lettuce (Lactuca sativa L.) seedlings grown under drought stress (no irrigation) and control (well irrigated) treatments in controlled conditions for eight days. Measurements occurred at two-day intervals. Among ten CF parameters studied, effective quantum yield of photochemical energy conversion in PSII (Y(PSII)), coefficient of photochemical quenching (qP), and coefficient of photochemical quenching of variable fluorescence based on the lake model of PSII (qL) significantly decreased in drought-stressed seedlings from day 6 of treatment compared to control. In contrast, maximum quantum yield (Fv/Fm), ratio of fluorescence (Rfd), and quantum yield of non-regulated energy dissipation in PSII (Y(NO)) were significantly affected only at the end. All growth parameters decreased in drought-stressed seedlings compared to control. Proline started increasing from day 4 and showed ~660-fold elevation on day 8 compared to control. Chlorophyll, ascorbic acid, TPC, TFC, and antioxidant activities decreased in drought-stressed seedlings. Results showed major changes in all parameters in seedlings under prolonged drought stress. These findings clarify effects of drought stress in lettuce seedlings during progressive drought exposure and will be useful in the seedling industry.

scholarly journals Comparative research of photosynthetic processes in selected poikilohydric organisms from Mediterranean and Central-European alpine habitats

2018 ◽  
Vol 8 (2) ◽  
pp. 286-298
Author(s):  
Gabriella Nora Maria Giudici ◽  
Josef Hájek ◽  
Miloš Barták ◽  
Svatava Kubešová
Keyword(s):  
Czech Republic ◽  
Chlorophyll Fluorescence ◽  
Photochemical Quenching ◽  
Marchantia Polymorpha ◽  
Effective Quantum Yield ◽  
Response Curves ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters ◽  
Mediterranean Habitats ◽  
Non Photochemical Quenching

Dehydration-induced decrease in photosynthetic activity was investigated in five poikilohydric autotrophs using chlorophyll fluorescence parameters recorded during controlled desiccation. For the study, two representatives of mosses from alpine zone (Rhizomnium punctatum, Rhytidiadelphus squarrosus) of the Jeseníky Mts. (Czech Republic) were used. Other two experimental species were mediterranean habitats liverwort (Pellia endiviifolia) and moss (Palustriella commutata), collected from under Woodwardia radicans canopy in the Nature Reserve Valle delle Ferriere (Italy). The last species was a liverwort (Marchantia polymorpha) collected from lowland site (Brno, Moravia, Czech Republic). We investigated the relationship between relative water content (RWC) and several chlorophyll fluorescence parameters evaluating primary photochemical processes of photosynthesis, such as effective quantum yield of photosynthetic processes in photosystem II (ΦPSII), and non-photochemical quenching (qN). With desiccation from fully wet (RWC = 100%) to dry state (RWC = 0%), ΦPSII exhibited a rapid (R. punctatum) and slow decline of ΦPSII (R. squarrosus, P. endiviifolia, M. polymorpha, and P. commutata). Shapes of dehydration-response curves were species-specific. RWC0.5, i.e. the RWC at which the sample showed half of maximum ΦPSII, reflected the species-specificity. It reached 65% in desiccation sensitive (R. punctatum), 53% and 43% in semi-tolerant (P. commutata and R. squarrosus), 24% and 18% in desiccation-tolerant species (P. endiviifolia and M. polymorpha). In all experimental species, non-photochemical quenching (qN) of absorbed light energy showed high values at RWC = 100% and a slight increase with desiccation. Steady state chlorophyll fluorescence (FS) remained high during desiccation and was not correlated with ΦPSII.  

scholarly journals Changes in Photo-Protective Energy Dissipation of Photosystem II in Response to Beneficial Bacteria Consortium in Durum Wheat under Drought and Salinity Stresses

2020 ◽  
Vol 10 (15) ◽  
pp. 5031 ◽  
Author(s):  
Mohammad Yaghoubi Khanghahi ◽  
Sabrina Strafella ◽  
Carmine Crecchio
Keyword(s):  
Chlorophyll Fluorescence ◽  
Energy Dissipation ◽  
Quantum Yield ◽  
Photosystem Ii ◽  
Excitation Energy ◽  
Durum Wheat ◽  
Photochemical Quenching ◽  
Plant Growth Promoting Bacteria ◽  
Psii Photochemistry ◽  
Non Photochemical Quenching

The present research aimed at evaluating the harmless dissipation of excess excitation energy by durum wheat (Triticum durum Desf.) leaves in response to the application of a bacterial consortium consisting of four plant growth-promoting bacteria (PGPB). Three pot experiments were carried out under non-stress, drought (at 40% field capacity), and salinity (150 mM NaCl) conditions. The results showed that drought and salinity affected photo-protective energy dissipation of photosystem II (PSII) increasing the rate of non-photochemical chlorophyll fluorescence quenching (NPQ (non-photochemical quenching) and qCN (complete non-photochemical quenching)), as well as decreasing the total quenching of chlorophyll fluorescence (qTQ), total quenching of variable chlorophyll fluorescence (qTV) and the ratio of the quantum yield of actual PSII photochemistry, in light-adapted state to the quantum yield of the constitutive non-regulatory NPQ (PQ rate). Our results also indicated that the PGPB inoculants can mitigate the adverse impacts of stresses on leaves, especially the saline one, in comparison with the non-fertilized (control) treatment, by increasing the fraction of light absorbed by the PSII antenna, PQ ratio, qTQ, and qTV. In the light of findings, our beneficial bacterial strains showed the potential in reducing reliance on traditional chemical fertilizers, in particular in saline soil, by improving the grain yield and regulating the amount of excitation energy.

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