CURRENT MICROBIOLOGY
·
2014
·Vol. 70
·期 1
·27-34
·
IF 1.359
Wang Shuzhi,Pan Xiangliang,Zhang Daoyong
The
knowledge of the effects of Sb(V) on the physiological characteristics of cyanobacteria was still limited. In the present study, responses of photosystem I and II (PSI and PSII), cyclic electron flow (CEF), and interphotosystem electron transport of Microcystis aeruginosa to 5–100 mg/l Sb(V) were synchronously measured using the Dual-PAM-100. 5 mg/l Sb (V) significantly inhibited PSII activity, but had no significant effects on PSI activity. At higher concentrations of Sb(V), the quantum yield and electron transport of PSI were less affected compared to PSII. The ratio of Y (II)/ Y (I) significantly decreased with increasing Sb(V) concentration. It decreased from 0.7 for control to 0.4 for 100 mg/l Sb(V)-treated cells, indicating that the change of the distribution of quantum yields between two photosystems and more serious inhibition of PSII under stress of Sb(V) compared to PSI. CEF was activated associated with the inhibition of linear electron flow after exposure to Sb(V). The contribution of Y (CEF) to the quantum yield and activity of PSI increased with increasing Sb(V) concentrations. The cyclic electron transport rate made a significant contribution to electron transport rate of PSI, especially at high Sb(V) concentration (100 mg/l) and high illumination (above 555 μmol photons/m 2 /s). The stimulation of CEF was essential for the higher tolerance of PSI than PSII to Sb(V).
研究领域:
植物学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2021
·
IF 5.279
Yanjing Guo,Weizhe Liu,He Wang,Xiaoxiong Wang,Sheng Qiang,Hazem M. Kalaji,Reto Jörg Strasser,Shiguo Chen
A biocontrol method plays an important role in weed management. In this study, we aimed to clarify the phytotoxicity of the mycotoxin patulin (PAT) and reveal its mode of action as a new natural photosystem II (PSII) inhibitor. Phytotoxicity test showed that PAT has herbicidal activity and causes significant leaf lesions on Ageratina adenophora. Under a half-inhibition concentration I50 (2.24 μM), the observed significant decrease in oxygen evolution rate and the increase in the J-step of the chlorophyll fluorescence rise OJIP curve indicated that PAT strongly reduces photosynthetic efficiency by blocking electron transport from the primary to secondary plastoquinone acceptors (QA to QB) of PSII. Molecular modeling of PAT docking to the A. adenophora D1 protein suggested that PAT bounds to the QB site by forming hydrogen bonds to histidine 252 in the D1 protein. It is proposed that PAT is a new natural PSII inhibitor and has the potential to be developed into a bioherbicide or used as a template scaffold for discovering novel derivatives with more potent herbicidal activity.
研究领域:
植物学
·
分子生物学
·
农业科学
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DOI
高影响因子
CURRENT MICROBIOLOGY
·
2012
·Vol. 65
·期 6
·733-741
·
IF 1.815
Wang Shuzhi,Pan Xiangliang
In this study, effects of antimony Sb(V) on growth, pigments content, oxygen evolution, and photosystem II (PSII) activity of Microcystis aeruginosa were investigated. JIP-test, Q
− A
reoxidation kinetic test and S-state test were used in this study to study the energy distribution and electron transport in PSII. Treatment with Sb(V) at various concentrations ranging from 5 to 100 mg/l had long-term effects on growth, pigments content, and oxygen evolution of M . aeruginosa . Low concentration of Sb(V) had no significant inhibition of the biomass production and PSII activity but inhibited the pigment synthesis. Growth, pigments content, oxygen evolution, and PSII activity were seriously inhibited when treated by high concentration of Sb(V) (100 mg/l). The target sites of Sb(V) toxic effect on the PSII of M . aeruginosa were mainly on the donor side and the apparatus in the light-dependent reaction. The quantum yield for photochemistry, density of reaction centers and photosynthesis performance index decreased, whereas the dissipated energy increased. PSII activity of M . aeruginosa was promoted when exposure to 50 mg/l Sb(V) by increasing the density of active reaction centers and electron transport after Q
− A
.
研究领域:
环境科学
·
微生物学
·
植物生理学
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DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Zhiheng Li,Jiazheng Chen,Jie Chen,Jiaojun Jin,Hanmei Chen,Huijun Liu
Due to the persistence of ionic liquids (ILs) in aquatic environments, it is necessary to reveal their ecological risk to aquatic organisms. Herein, the biotoxicity of two alkyl-methylimidazolium nitrate ILs ([C 10 mim]NO 3 and [C 12 mim]NO 3 ) against Scenedesmus obliquus were studied. Results showed that the growth inhibition of S. obliquus increased with increasing concentrations of ILs, maximum values of 94.61% at 4 mg/L of [C 10 mim]NO 3 and 97.34% at 0.8 mg/L of [C 12 min]NO 3 were observed. The fluorescence parameters of photosystem II, such as light quantum yield and electron transfer rate, showed a negative relationship with the exposure dose. [C 12 mim]NO 3 had a more significant effect than [C 10 mim]NO 3 . Moreover, the redox homeostasis of algae was disrupted; the accumulation of reactive oxygen species , leading to obvious inhibition of superoxide dismutase and catalase activities was observed. A metabolomic analysis indicated that the contents of most metabolites were reduced significantly, and fructose and galactose decreased significantly by 42.3% and 88.6%, respectively, in the [C 10 mim]NO 3 treatment compared to those in the control. The inhibition of amino acid biosynthesis and glyoxylate and dicarboxylate metabolism explained the more serious biotoxicity of [C 12 mim]NO 3 than that of [C 10 mim]NO 3 . This study facilitates a better understanding of the environmental safety and ecological risks of ILs.
研究领域:
环境科学
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植物生理学
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DOI
PubMed
高影响因子
Marine Drugs
·
2021
·Vol. 19
·期 6
·336
·
IF 5.118
Ni Wu,Mengmeng Tong,Siyu Gou,Weiji Zeng,Zhuoyun Xu,Tianjiu Jiang
Chattonellaspecies,C. marinaandC. ovata, are harmful raphidophycean flagellates known to have hemolytic effects on many marine organisms and resulting in massive ecological damage worldwide. However, knowledge of the toxigenic mechanism of these ichthyotoxic flagellates is still limited. Light was reported to be responsible for the hemolytic activity (HA) ofChattonellaspecies. Therefore, the response of photoprotective, photosynthetic accessory pigments, the photosystem II (PSII) electron transport chain, as well as HA were investigated in non-axenicC. marinaandC. ovatacultures under variable environmental conditions (light, iron and addition of photosynthetic inhibitors). HA and hydrogen peroxide (H2O2) were quantified using erythrocytes and pHPA assay. Results confirmed that% HA ofChattonellawas initiated by light, but was not always elicited during cell division. Exponential growth ofC. marinaandC. ovataunder the light over 100 µmol m−2s−1or iron-sufficient conditions elicited high hemolytic activity. Inhibitors of PSII reduced the HA ofC. marina, but had no effect onC. ovata. The toxicological response indicated that HA inChattonellawas not associated with the photoprotective system, i.e., xanthophyll cycle and regulation of reactive oxygen species, nor the PSII electron transport chain, but most likely occurred during energy transport through the light-harvesting antenna pigments. A positive, highly significant relationship between HA and chlorophyll (chl) biosynthesis pigments, especially chlc2and chla, in both species, indicated that hemolytic toxin may be generated during electron/energy transfer through the chlc2biosynthesis pathway.Keywords:Chattonella marina;Chattonella ovata;hemolytic activity;photosystem II;hydrogen peroxide;chlorophyllc2
研究领域:
生物学
·
生态学
·
毒理学
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DOI
PubMed
高影响因子
PEST MANAGEMENT SCIENCE
·
2023
·Vol. 80
·期 1
·133-148
·
IF 4.1
Qian Yang,Yanjing Guo,He Wang,Zhi Luo,Ying Chen,Mengyun Jiang,Huan Lu,Bernal E. Valverde,Sheng Qiang,Reto Jörg Strasser,Shiguo Chen
BACKGROUND Bioherbicides are becoming more attractive as safe weed control tools towards sustainable agriculture. Natural products constitute an important source chemicals and chemical leads for discovery and development of novel pesticide target sites. Citrinin is a bioactive compound produced by fungi of the genera Penicillium and Aspergillus . However, its physiological-biochemical mechanism as a phytotoxin remains unclear. RESULTS Citrinin causes visible leaf lesions on Ageratina adenophora similar to those produced by the commercial herbicide bromoxynil. Phytotoxicity bioassay tests using 24 plant species confirmed that citrinin has a broad activity spectrum and therefore has potential as a bioherbicide. Based on chlorophyll fluorescence studies, citrinin mainly blocks PSII electron flow beyond plastoquinone Q A at the acceptor side, resulting in the inactivation of PSII reaction centers. Furthermore, molecular modeling of citrinin docking to the A. adenophora D1 protein suggests that it binds to the plastoquinone Q B site by a hydrogen bond between the O1 hydroxy oxygen atom of citrinin and the histidine 215 of the D1 protein, the same way as classical phenolic PSII herbicides do. Finally, 32 new citrinin derivatives were designed and sorted according to free energies on the basis of the molecular model of an interaction between the citrinin molecule and the D1 protein. Five of the modeled compounds had much higher ligand binding affinity within the D1 protein compared with lead compound citrinin. CONCLUSION Citrinin is a novel natural PSII inhibitor that has the potential to be developed into a bioherbicide or utilized as a lead compound for discovery of new derivatives with high herbicidal potency. © 2023 Society of Chemical Industry.
研究领域:
植物学
·
农业科学
·
分子生物学
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DOI
PubMed
高影响因子
PHYCOLOGIA
·
2015
·
IF 1.915
Rui Liu,Xiaofei Ran,Fang Bai,Jinzhu Xu,Songqi Yang,Junqiong Shi,Zhongxing Wu
In order to investigate the toxicity targets of the secondary metabolite from aquatic plants, N-phenyl-2-naphthylamine, on Cylindrospermopsis raciborskii photosynthetic system II (PSII), we determined chlorophyll a (Chl a), specific growth rate (μ−d), photosynthetic rapid light curves and polyphasic Chl a fluorescence transients following exposure to N-phenyl-2-naphthylamine. The results showed significant decreases in Chl a following 48 h at high concentration (0.50 mg l−1) exposure to N-phenyl-2-naphthylamine. The PSII electron transfer rate and Chl a fluorescence transients appeared to be affected after the cells were exposed to concentrations of 0.50, 1.00 and 2.00 mg l−1. Exposure to higher concentration of N-phenyl-2-naphthylamine (> 0.50 mg l−1) mainly depressed the density of reaction centers (RC/CS0) and quantum energy flux ratios (ϕP0 and ϕE0) but increased the absorption flux per RC (ABS/RC), dissipated energy flux per RC (DI0/RC) and the average redox state of QA−/QA in the time span from 0 to tFmax (Sm/tFmax). However, exposure to low concentration (≤ 0.5 mg l−1) mainly inhibited the trapping energy fluxes per reaction center (TR0/RC), electron transport energy fluxes per reaction center (ET0/RC) and energy flux ratio (ψ0). This suggested that the donor and the acceptor sides of PSII were targets of N-phenyl-2-naphthylamine in C. raciborskii. Additionally, our results indicated that the toxicity target at low concentrations of N-phenyl-2-naphthylamine was at each step of electron transport between QA− and the Cyt b6/f complex; whereas, the reduction of QA was the potential target at high concentrations. We suggest that N-phenyl-2-naphthylamine may be a potential allelochemical to control harmful cyanobacterial blooms.
研究领域:
水生生物学
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环境科学
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植物生理学
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产品关联
DOI
高影响因子
CHEMOSPHERE
·
2016
·
IF 3.698
Liqiao Jin,Xingkai Che,Zishan Zhang,Yuting Li,Huiyuan Gao,Shijie Zhao
Phenanthrene is a polycyclic aromatic hydrocarbon (PAH) that is widely distributed in the environment and seriously affects the growth and development of plants. To clarify the mechanisms of the direct effects of phenanthrene on the plant photosynthetic apparatus, we measured short-term phenanthrene-treated cucumber leaves. Phenanthrene inhibited Rubisco carboxylation activity, decreasing photosynthesis rates (Pn). And phenanthrene inhibited photosystem II (PSII) activity, thereby blocking photosynthetic electron transport. The inhibition of the light and dark reactions decreased the photosynthetic electron transport rate (ETR) and increased the excitation pressure (1−qP). Under high light, the maximum photochemical efficiency of photosystem II (F v /F m ) in phenanthrene-treated cucumber leaves decreased significantly, but photosystem I (PSI) activity (Δ I/I o ) did not. Phenanthrene also caused a J-point rise in the OJIP curve under high light, which indicated that the acceptor side of PSII Q A to Q B electron transfer was restricted. This was primarily due to the net degradation of D1 protein, which is caused by the accumulation of reactive oxygen species (ROS) in phenanthrene-treated cucumber leaves under high light. This study demonstrated that phenanthrene could directly inhibit photosynthetic electron transport and Rubisco carboxylation activity to decrease net Pn. Under high light, phenanthrene caused the accumulation of ROS, resulting in net increases in D1 protein degradation and consequently causing PSII photoinhibition .
研究领域:
植物生理学
·
环境科学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
CURRENT MICROBIOLOGY
·
2024
·Vol. 82
·期 1
·1-12
·
IF 2.3
Cheng Jie,Tan Long,Lu Xue,Zheng Mengyu,Xu Chengshuai,Xu Wei,Jiang Tong,Zhang Chaobo
In recent years, the frequent occurrence of algal blooms has posed continuous threats to aquatic ecosystems and social safety. Environmentally friendly algae-inhibiting methods utilizing allelopathic substances offer advantages such as convenient application and low costs, presenting a bright application prospect in the fields of water and ecological restoration. This study aimed to investigate the procedure for extracting total flavonoids from Zanthoxylum bungeanum leaves and assess allelopathic mechanism of Z. bungeanum leaf extracts on Microcystis aeruginosa . The optimal extraction conditions were determined as follows: solvent-to-material ratio = 10 mL/g; extraction time = 55 min; ethanol volume fraction = 80%; and ultrasonic temperature = 80 °C. Antioxidant activity tests revealed that Z. bungeanum leaf extracts exhibit superior capacity compared to Butylated hydroxytoluene (BHT) but inferior to Vitamin C (VC). Moreover, high-concentration Z. bungeanum leaf extracts can disrupt the structures of oxygen-evolving complexes at the donor sides of photosystem II (PSII) reaction center and influence energy distribution at PSII reaction centers, thereby inhibiting electron transmission activities at both donor and receptor sides of the PSII reaction center. The elucidated allelopathic mechanism of Z. bungeanum leaf extracts provides theoretical evidence for the algal-bloom control and the development of allelopathic algae-inhibiting agents, offering a reference for the further comprehensive development and utilization of Z. bungeanum . Graphical High-concentration Z. bungeanum leaf extracts can disrupt the structures of oxygen-evolving complexes at the donor sides of photosystem II (PSII) reaction center and influence energy distribution at PSII reaction centers, thereby inhibiting electron transmission activities at both donor and receptor sides of the PSII reaction center.
研究领域:
环境科学
·
植物学
·
生态学
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DOI
PubMed
高影响因子
ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY
·
2017
·Vol. 74
·期 4
·515-526
·
IF 2.467
Xiang Rong,Shi Junqiong,Yu Yi,Zhang Hongbo,Dong Congcong,Yang Yanjun,Wu Zhongxing
To investigate the effect of bisphenol A (BPA) on Cylindrospermopsis raciborskii (Cyanobacteria) and Scenedesmus quadricauda (Chlorophyta), we grew the two species at BPA concentrations of 0, 0.1, 1, 2, 5, 10, and 20 mg/L and examined their growth, lipid peroxidation, antioxidant enzyme activity, and chlorophyll a fluorescence. The 96-h EC 50 values (effective concentration causing 50% growth inhibition) for BPA in C. raciborskii and S. quadricauda were 9.663 ± 0.047, and 13.233 ± 0.069 mg/L, respectively. A significant reduction in chlorophyll a concentration was found in C. raciborskii and S. quadricauda when BPA concentrations were greater than 1 and 2 mg/L, respectively. Furthermore, F
v / F
m , Δ F / F
m ′, and qP decreased significantly at 10 mg/L BPA in C. raciborskii but started to decrease at 10 mg/L in S. quadricauda. The changes in chlorophyll fluorescence parameters ( α , rETR max ) that were obtained from the rapid light response curves of both algae species showed similar responses to F
v / F
m , Δ F / F
m ′, and qP under BPA-induced stress. Values for all of the chlorophyll fluorescence parameters in S. quadricauda were higher than in C. raciborskii ; however, the nonphotochemical quenching measured in C. raciborskii was considerably higher than it was in S. quadricauda . In addition, lipid peroxidation (determined as MDA content) and antioxidant enzyme activities (SOD and CAT) increased in both species as the BPA concentration increased. These results suggest that C. raciborskii is more sensitive to the effects of BPA than S. quadricauda and that photosystem II might be a target for the activity of BPA in vivo.
研究领域:
环境科学
·
植物生理学
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产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2016
·
IF 3.976
Zunwei Chen,Shufang Song,Yuezhong Wen
The priority pollutant chromium (Cr) was ubiquitous and great efforts have been made to reduce Cr (VI) into less-toxic Cr (III) by alga for the convenient availability and low expense. However, the functional role of organelle inside the algal cell in Cr (VI) reduction was poorly understood. In this study, organelles in green algae Chlorella vulgaris were extracted and further decorated for Cr (VI) reduction tests. Results showed that the chloroplast exhibited not only adsorption ability of total Cr (21.18% comparing to control) but also reduction potential of Cr (VI) (almost 70% comparing to control), whose most suitable working concentration was at 17 μg/mL. Furtherly, the isolated thylakoid membrane (ITM) showed better Cr (VI) reduction potential with the presence of sodium alginate (SA), even though the Hill reaction activity (HRA) was inhibited. As for photosystem II (PSII), the addition of mesoporous silica SBA-15 enhanced the reduction ability through improving the light-harvesting complex (LHC) II efficiency and electron transport rate. On the whole, the reduction ability order of the three kinds of materials based on chloroplast in C. vulgaris was PSII@SBA-15 > Chloroplast > ITM@SA. The attempt made in this study to reduce the Cr (VI) with C. vulgaris organelles might not only offer basement to detect the potential action mechanism of Cr (VI) reduction by C. vulgaris but also provide a new sight for the scavenge of heavy metal with biological materials.
研究领域:
环境科学
·
生物技术
·
污染控制
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产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2022
·
IF 12.92
Yuehui Li,Duanhui Si,Wangyin Wang,Song Xue,Wenzhe Shang,Zhanyou Chi,Can Li,Ce Hao,Govindjee Govindjee,Yantao Shi
For natural oxygenic photosynthesis, there is a consensus that H 2 O is oxidized to molecular oxygen by photosystem II (PSII) in the grana, while CO 2 assimilation takes place, long after oxygen evolution, in light-independent reactions, for example, through the Calvin-Benson Cycle in the stroma. Here, we report, for the first time, light-driven CO 2 assimilation by the PSII core complex, where the formation of methanol, along with the oxygen evolution, is validated by in - situ mass spectrometry, gas chromatography and isotopic labeling experiments. Such an unusual CO 2 assimilation is likely to be a simultaneous event along with the usual electron transfer occurring in normal light–independent assimilation. This discovery is extraordinary and is of great significance as it may substantially modify our understanding of the mechanism of photosynthesis.
研究领域:
植物生理学
·
光合作用
·
生物化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）