Acclimatization of photosynthetic apparatus and antioxidant metabolism to excess soil cadmium in Buddleja spp.

AbstractHeavy metal (HM) pollutants can cause serious phytotoxicity or oxidative stress in plants. Buddleja L., commonly known as “butterfly bushes”, are frequently found growing on HM-contaminated land. However, to date, few studies have focused on the physiological and biochemical responses of Buddleja species to HM stress. In this study, potted seedlings of B. asiatica Lour. and B. macrostachya Wall. ex Benth. were subjected to various cadmium (Cd) concentrations (0, 25, 50, 100, and 200 mg kg−1) for 90 days. Both studied Buddleja species showed restricted Cd translocation capacity. Exposure to Cd, non-significant differences (p > 0.05) were observed, including quantum yield of photosystem II (PSII), effective quantum yield of PSII, photochemical quenching and non-photochemical quenching in both species between all studied Cd concentrations. Moreover, levels of cellular reactive oxygen species (ROS) significantly declined (p < 0.05) with low malondialdehyde concentrations. In B. asiatica, high superoxide dismutase and significantly enhanced (p < 0.05) peroxidase (POD) activity contributed greatly to the detoxification of excess ROS, while markedly enhanced POD activity was observed in B. macrostachya. Additionally, B. macrostachya showed higher membership function values than did B. asiatica. These results suggested that both Buddleja species exhibited high Cd resistance and acclimatization.

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Change in H+ Transport across Thylakoid Membrane as Potential Mechanism of 14.3 Hz Magnetic Field Impact on Photosynthetic Light Reactions in Seedlings of Wheat (Triticum aestivum L.)

Plants ◽

10.3390/plants10102207 ◽

2021 ◽

Vol 10 (10) ◽

pp. 2207

Author(s):

Ekaterina Sukhova ◽

Ekaterina Gromova ◽

Lyubov Yudina ◽

Anastasiia Kior ◽

Yana Vetrova ◽

...

Keyword(s):

Quantum Yield ◽

Photosystem Ii ◽

Thylakoid Membrane ◽

Photochemical Quenching ◽

Effective Quantum Yield ◽

Terrestrial Plants ◽

Short Term ◽

Low Frequencies ◽

Resonance Frequencies ◽

Non Photochemical Quenching

Natural and artificial extremely low-frequency magnetic fields (ELFMFs) are important factors influencing physiological processes in living organisms including terrestrial plants. Earlier, it was experimentally shown that short-term and long-term treatments by ELFMFs with Schumann resonance frequencies (7.8, 14.3, and 20.8 Hz) influenced parameters of photosynthetic light reactions in wheat leaves. The current work is devoted to an analysis of potential ways of this ELFMF influence on the light reactions. Only a short-term wheat treatment by 14.3 Hz ELFMF was used in the analysis. First, it was experimentally shown that ELFMF-induced changes (an increase in the effective quantum yield of photosystem II, a decrease in the non-photochemical quenching of chlorophyll fluorescence, a decrease in time of changes in these parameters, etc.) were observed under the action of ELFMF with widely ranging magnitudes (from 3 to 180 µT). In contrast, the potential quantum yield of photosystem II and time of relaxation of the energy-dependent component of the non-photochemical quenching were not significantly influenced by ELFMF. Second, it was shown that the ELFMF treatment decreased the proton gradient across the thylakoid membrane. In contrast, the H+ conductivity increased under this treatment. Third, an analysis of the simplest mathematical model of an H+ transport across the thylakoid membrane, which was developed in this work, showed that changes in H+ fluxes related to activities of the photosynthetic electron transport chain and the H+-ATP synthase were not likely a mechanism of the ELFMF influence. In contrast, changes induced by an increase in an additional H+ flux (probably, through the proton leakage and/or through the H+/Ca2+ antiporter activity in the thylakoid membrane) were in good accordance with experimental results. Thus, we hypothesized that this increase is the mechanism of the 14.3 Hz ELFMF influence (and, maybe, influences of other low frequencies) on photosynthetic light reactions in wheat.

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Physiological characterization of grapevine rootstocks grown in soil with increasing zinc doses

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v19n10p973-980 ◽

2015 ◽

Vol 19 (10) ◽

pp. 973-980 ◽

Cited By ~ 1

Author(s):

Jovani Zalamena ◽

George W. Melo ◽

Henrique P. Santos ◽

Leandro S. da Silva ◽

Flavio B. Fialho ◽

...

Keyword(s):

Quantum Yield ◽

Photosystem Ii ◽

Fluorescence Analysis ◽

Photochemical Quenching ◽

Effective Quantum Yield ◽

Physiological Characterization ◽

Physiological Variables ◽

Negative Effect ◽

Soil Zn ◽

Non Photochemical Quenching

ABSTRACTThis study aimed to evaluate the performance of grapevine rootstocks under increasing levels of Zn in the soil and to identify physiological variables that can be used as indicators of excess of Zn in the soil. The rootstocks SO4, Paulsen1103, IAC572, IAC313 and 420A were grown in pots containing soil, which received Zn doses of 0, 20, 40, 80 or 160 mg kg-1 of soil. Dry matter (DM), Zn content in shoots and roots, chlorophyll index, initial fluorescence (Fo), maximum fluorescence (Fm), maximum quantum yield of photosystem II (Fv/Fm), effective quantum yield of photosystem II (Y-II) and non-photochemical quenching (NPQ) were evaluated. The increase of Zn levels in the soil decreased DM in all rootstocks, and IAC572 was superior to the others. The variation in the indices of chlorophyll a and b had little expression in relation the soil Zn levels, but allowed identifying that the rootstocks Paulsen 1103, 420A and SO4 are sensitive to Zn toxicity and that IAC572 and IAC313 were not sensitive to the tested levels. Fluorescence analysis showed a negative effect of Zn contents on the variables Fo, Fm, Y-II and NPQ in all rootstocks, which proved to be good indicators of Zn phytotoxicity.

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Photoacclimation in three species of freshwater red algae

Brazilian Journal of Plant Physiology ◽

10.1590/s1677-04202007000100003 ◽

2007 ◽

Vol 19 (1) ◽

pp. 23-34 ◽

Cited By ~ 13

Author(s):

Anna I.N. Bautista ◽

Orlando Necchi Jr.

Keyword(s):

Quantum Yield ◽

High Irradiance ◽

Photochemical Quenching ◽

Effective Quantum Yield ◽

Low Light ◽

Recovery Capacity ◽

Long Time ◽

Freshwater Red Algae ◽

Non Photochemical Quenching ◽

Short Time

Three freshwater Rhodophyta species (Audouinella eugenea, A. hermannii and Compsopogon coeruleus) were tested as to their responses (photosynthesis, growth and pigment concentration) to two irradiances (low light, LL, 65 µmol m-2 s-1 and high light, HL, 300 µmol m-2 s-1) and two periods (short time, ST, 4 d, and long time, LT, 28 d). Higher growth rates were consistently observed at LL but significant differences were observed only for A. hermannii. Higher values of photoinhibition at LL were found for the three species, which is consistent with the dynamic photoinhibition as a reversible photoprotective mechanism against high irradiance. Light-induced decreases of effective quantum yield (EQY) were observed in the three species consisting of pronounced decreases from LL to HL. Rapid increases of non-photochemical quenching (NPQ) were observed mainly at LL, indicating energy dissipation by reaction centers. Results revealed distinct photoacclimation strategies to deal with high irradiances: the two Audouinella species had only characteristics of shade-adapted algae: acclimation by changes of size of photosystem units (PSU) under LT and by PSU number under ST; higher values of the photoinhibition parameter (beta) and NPQ, and lower values of EQY at LL; higher recovery capacity of potential quantum yield (PQY) at LL and under ST; highly significant positive correlation of electron transport rate (ETR) with NPQ. In addition, C. coeruleus mixed some characteristics of sun-adapted algae: acclimation by changes of PSU number under LT and by PSU size under ST; higher recovery capacity of EQY than the other two species; weak or no correlation of ETR with NPQ. Thus, these characteristics indicate that C. coeruleus cope with high irradiances more efficiently than the Audouinella species.

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Assessment of Heat-tolerance Potential in QTL Introgressed Lines of Hybrid Rice Restorer, KMR-3R through PS-II Efficiency

International Journal of Environment and Climate Change ◽

10.9734/ijecc/2021/v11i1130540 ◽

2021 ◽

pp. 258-266

Author(s):

V. Jaldhani ◽

D. Sanjeeva Rao ◽

P. Beulah ◽

B. Srikanth ◽

P. R. Rao ◽

...

Keyword(s):

High Temperature ◽

Quantum Yield ◽

Temperature Stress ◽

Heat Tolerance ◽

Photosynthetic Apparatus ◽

High Temperature Stress ◽

Maximum Efficiency ◽

Photochemical Quenching ◽

Psii Photochemistry ◽

Heat Tolerant

Aims: To assess heat-induced PSII damage and efficiency in eight promising backcross introgression lines (BC2F6) of KMR-3R/N22 possessing qHTSF1.1 and qHTSF4.1. Study Design: Randomized Complete Block Design (RCBD) with three replications. Place and Duration of Study: ICAR-Indian Institute of Rice Research, Hyderabad India during wet/rainy (Kharif) season 2018. Methodology: Eight ILs (BC2F6) and parents were evaluated for heat tolerance. The high- temperature stress was imposed by enclosing the crop with a poly cover tent (Polyhouse) just before the anthesis stage. The fluorescence parameters viz., maximum efficiency of PSII photochemistry (Fv/Fm), Electron transport rate (ETR), effective PSII quantum yield (ΦPSII), coefficient of photochemical quenching (qP) and coefficient of non-photochemical quenching (qN) were measured under ambient and high-temperature stress. Results: The heat-tolerance potential of ILs was assessed in terms of PSII activity. The results indicated that significant differences were observed between treatments (T), genotypes (G) and the interaction between T × G. The physiological basis of introgressed QTLs controls the spikelet fertility by maintaining the productive and adaptive strategies in heat-tolerant QTL introgressed lines with stable photosynthetic apparatus (PSII) under high-temperature stress. Conclusion: The Fv/Fm ratio denotes the maximum quantum yield of PSII. The heat-tolerant QTL introgressed lines exhibited stable photosynthetic apparatus (PSII) and noted better performance under high-temperature stress. They may be used as donors for fluorescence traits in breeding rice for high-temperature tolerance.

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Acquired tolerance of the photosynthetic apparatus to photoinhibition as a result of growing Solanum lycopersicum at moderately higher temperature and light intensity

Functional Plant Biology ◽

10.1071/fp18264 ◽

2019 ◽

Vol 46 (6) ◽

pp. 555 ◽

Cited By ~ 2

Author(s):

Milena T. Gerganova ◽

Aygyun K. Faik ◽

Maya Y. Velitchkova

Keyword(s):

High Temperature ◽

Quantum Yield ◽

Light Intensity ◽

Electron Flow ◽

Photosynthetic Apparatus ◽

High Light ◽

Cyclic Electron Flow ◽

Photochemical Quenching ◽

Kinetics Of ◽

Moderately High Temperature

The kinetics of photoinhibition in detached leaves from tomato plants (Solanium lycopersicum L. cv. M82) grown for 6 days under different combinations of optimal and moderately high temperature and optimal and high light intensity were studied. The inhibition of PSII was evaluated by changes in maximal quantum yield, the coefficient of photochemical quenching and the quantum yield of PSII. The changes of PSI activity was estimated by the redox state of P700. The involvement of different possible protective processes was checked by determination of nonphotochemical quenching and cyclic electron flow around PSI. To evaluate to what extent the photosynthetic apparatus and its response to high light treatment was affected by growth conditions, the kinetics of photoinhibition in isolated thylakoid membranes were also studied. The photochemical activities of both photosystems and changes in the energy distribution and interactions between them were evaluated by means of a Clark electrode and 77 K fluorescence analysis. The data showed an increased tolerance to photoinhibition in plants grown under a combination of moderately high temperature and light intensity, which was related to the stimulation of cyclic electron flow, PSI activity and rearrangements of pigment–protein complexes, leading to a decrease in the excitation energy delivered to PSII.

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Salt stress resilience potential of a fungal inoculant isolated from tea cultivation area in maize

Biologia ◽

10.1515/biolog-2017-0068 ◽

2017 ◽

Vol 72 (6) ◽

Cited By ~ 3

Author(s):

Nuran Durmus ◽

Abdullah Muhammed Yesilyurt ◽

Necla Pehlivan ◽

Sengul Alpay Karaoglu

Keyword(s):

Salt Stress ◽

Water Status ◽

Cost Effective ◽

Nacl Stress ◽

Photochemical Quenching ◽

Effective Quantum Yield ◽

Stress Resilience ◽

Ps Ii ◽

Tea Plants ◽

Non Photochemical Quenching

AbstractAgriculture needs to be sustained by organic processes in current era as population explosion energy and the number of individuals undernourished are raising public concerns. Global warming poses additional threat by lifting the damage of salt stress especially in agro-economically vital crops like maize whose cultivation dates back to Mayans. To that end, cost-effective and organic fungal agents may be great candidates in stress resilience. We isolated the fungal strain from the soil of tea plants and characterized that via 5.8 S rDNA gene with internal transcribed spacer ITS-1 and ITS-2 regions, then named the target strain as TA. Reduced maximum quantum efficiency of PS II (Fv/Fm), the effective quantum yield of PS2 (ΦPS2), electron transport rate (ETR), photochemical quenching (qP) and increased non-photochemical quenching (NPQ) were detected in maize plants stressed with dose dependent salt. Enhanced Fv/Fm, ΦPS2, ETR, qP and decreased NPQ was observed in TA primed plus NaCl treated plants. TA biopriming significantly increased the lengths, fresh and dry weights of root/shoots and decreased the lipid peroxidation. Maize seedlings bioprimed with TA had less MDA and higher soluble protein, proline, total chlorophyll, carotenoid and RWC under NaCl. Furthermore, SOD, GPX and GR activities were much more increased in root and leaves of TA primed seedlings, however CAT activity did not significantly change. This is the first report to our knowledge that TA reverses the damage of NaCl stress on maize growth through improving water status, antioxidant machinery and especially photosynthetic capacity.

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Comparisons of Chlorophyll Fluorescence and Physiological Characteristics of Wheat Seedlings Influenced by Iso-Osmotic Stresses from Polyethylene Glycol and Sodium Chloride

Agronomy ◽

10.3390/agronomy10030325 ◽

2020 ◽

Vol 10 (3) ◽

pp. 325

Author(s):

Chiu-Yueh Lan ◽

Kuan-Hung Lin ◽

Chun-Liang Chen ◽

Wen-Dar Huang ◽

Chang-Chang Chen

Keyword(s):

Chlorophyll Fluorescence ◽

Polyethylene Glycol ◽

Sodium Chloride ◽

Energy Dissipation ◽

Quantum Yield ◽

Photochemical Quenching ◽

Effective Quantum Yield ◽

Wheat Seedlings ◽

Level 3 ◽

Level 2

Wheat (Triticum aestivum) cultivar Taichung SEL.2 (TCS2) is a salt-tolerance variety, but the mechanism involved remains unclear. This study aims to distinguish between the non-ionic osmotic and salt-mediated physiological effects on TCS2. Osmotic agents polyethylene glycol (PEG) and sodium chloride (NaCl) were applied at three iso-osmotic levels, level 1 containing 24% (w/v) PEG and 200 mM NaCl, level 2 containing 26.5% (w/v) PEG and 250 mM NaCl), and level 3 containing 29% (w/v) PEG and 300 mM NaCl, respectively. According to the investigation of chlorophyll fluorescence in the better NaCl-treated seedlings, maximal quantum yield of photosystem II (PSII) (Fv/Fm) and significant higher effective quantum yield of PSII (ΦPSII) at level 3 were observed. Meanwhile, the non-photochemical quenching of PSII (NPQ) and the quantum yield of regulated energy dissipation of PSII [Y(NPQ)] were significantly higher in the NaCl-treated seedlings, and the quantum yield of non-regulated energy dissipation of PSII [Y(NO)] in the NaCl-treated seedlings was lower than the PEG-treated ones at level 2 and level 3. Furthermore, the less extensive degradation of photosynthetic pigments, the better ascorbate peroxidase (APX) activity and the less accumulation of malondialdehyde (MDA) were also observed in NaCl-treated seedlings. In the morphological traits, shoot elongation in NaCl-treated seedlings was also preserved. These results suggest that TCS2 is more resistant to NaCl-induced osmotic stress than to the PEG-induced stress. This study contributes to plant breeder interest in drought- and/or salt-tolerant wheat varieties.

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

Horticulturae ◽

10.3390/horticulturae7080238 ◽

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.

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

Czech Polar Reports ◽

10.5817/cpr2018-2-24 ◽

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.

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

Applied Sciences ◽

10.3390/app10155031 ◽

2020 ◽

Vol 10 (15) ◽

pp. 5031 ◽

Cited By ~ 1

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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