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Abstract
Mercury (Hg) is a global pollutant emitted primarily as gaseous Hg0 that is deposited in aquatic and terrestrial ecosystems following its oxidation to HgII. From that point, microbes play a key role in determining Hg’s fate in the environment by participating in sequestration, oxidation, reduction, and methylation reactions. A wide diversity of chemotrophic and phototrophic microbes occupying oxic and anoxic habitats are known to participate directly in Hg cycling. Over the last few years, new findings have come to light that have greatly improved our mechanistic understanding of microbe-mediated Hg cycling pathways in the environment. In this review, we summarize recent advances in microbially mediated Hg cycling and take the opportunity to compare the relatively well-studied chemotrophic pathways to poorly understood phototrophic pathways. We present how the use of genomic and analytical tools can be used to understand Hg transformations and the physiological context of recently discovered cometabolic Hg transformations supported in anaerobes and phototrophs. Finally, we propose a conceptual framework that emphasizes the role that phototrophs play in environmental Hg redox cycling and the importance of better characterizing such pathways in the face of the environmental changes currently underway.
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Affiliation(s)
- Daniel S. Grégoire
- Biology Department, University of Ottawa, 30 Marie Curie, Ottawa, ON K1N 6N5, Canada
| | - Alexandre J. Poulain
- Biology Department, University of Ottawa, 30 Marie Curie, Ottawa, ON K1N 6N5, Canada
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2
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Buffon G, Blasi ÉADR, Rativa AGS, Lamb TI, Gastmann R, Adamski JM, Schwambach J, Ricachenevsky FK, Heringer AS, Silveira V, Lopes MCB, Sperotto RA. Unraveling Rice Tolerance Mechanisms Against Schizotetranychus oryzae Mite Infestation. FRONTIERS IN PLANT SCIENCE 2018; 9:1341. [PMID: 30279693 PMCID: PMC6153315 DOI: 10.3389/fpls.2018.01341] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 08/24/2018] [Indexed: 05/17/2023]
Abstract
Rice is the staple food for over half of the world's population. Infestation of Schizotetranychus oryzae (Acari: Tetranychidae) causes great losses in rice productivity. To search for rice genotypes that could better tolerate S. oryzae infestation, we evaluated morphological and production parameters in Brazilian cultivars, and identified two cultivars with contrasting responses. Leaf damage during infestation was similar for all cultivars. However, infestation in Puitá INTA-CL resulted in reduction in the number of seeds per plant, percentage of full seeds, weight of 1,000 seeds, and seed length, whereas infestation in IRGA 423 increased weight of 1,000 seeds and seed length. Reduction in seed weight per plant caused by infestation was clearly higher in Puitá INTA-CL (62%) compared to IRGA 423 (no reduction detected), thus Puitá INTA-CL was established as susceptible, and IRGA 423 as tolerant to S. oryzae infestation. Photosynthetic parameters were less affected by infestation in IRGA 423 than in Puitá INTA-CL, evidencing higher efficiency of energy absorption and use. S. oryzae infestation also caused accumulation of H2O2, decreased cell membrane integrity (indicative of cell death), and accelerated senescence in leaves of Puitá INTA-CL, while leaves of IRGA 423 presented higher levels of total phenolics compounds. We performed proteomics analysis of Puitá INTA-CL and IRGA 423 leaves after 7 days of infestation, and identified 60 differentially abundant proteins (28 more abundant in leaves of Puitá INTA-CL and 32 in IRGA 423). Proteins related to plant defense, such as jasmonate synthesis, and related to other mechanisms of tolerance such as oxidative stress, photosynthesis, and DNA structure maintenance, together with energy production and general metabolic processes, were more abundant in IRGA 423. We also detected higher levels of silicon (as amorphous silica cells) in leaves of infested IRGA 423 plants compared to Puitá INTA-CL, an element previously linked to plant defense, indicating that it could be involved in tolerance mechanisms. Taken together, our data show that IRGA 423 presents tolerance to S. oryzae infestation, and that multiple mechanisms might be employed by this cultivar. These findings could be used in biotechnological approaches aiming to increase rice tolerance to mite infestation.
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Affiliation(s)
- Giseli Buffon
- Graduate Program in Biotechnology, Universidade do Vale do Taquari, Lajeado, Brazil
| | | | | | - Thainá Inês Lamb
- Biological Sciences and Health Center, Universidade do Vale do Taquari, Lajeado, Brazil
| | - Rodrigo Gastmann
- Biological Sciences and Health Center, Universidade do Vale do Taquari, Lajeado, Brazil
| | - Janete Mariza Adamski
- Graduate Program in Botany, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Joséli Schwambach
- Graduate Program in Biotechnology, Universidade de Caxias do Sul, Caxias do Sul, Brazil
| | - Felipe Klein Ricachenevsky
- Graduate Program in Agrobiology, Universidade Federal de Santa Maria, Santa Maria, Brazil
- Graduate Program in Cell and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Angelo Schuabb Heringer
- Laboratory of Biotechnology, Universidade Estadual do Norte Fluminense “Darcy Ribeiro” (UENF), Campos dos Goytacazes, Brazil
| | - Vanildo Silveira
- Laboratory of Biotechnology, Universidade Estadual do Norte Fluminense “Darcy Ribeiro” (UENF), Campos dos Goytacazes, Brazil
- Integrative Biology Unit, Genomic and Proteomic Facility, Universidade Estadual do Norte Fluminense “Darcy Ribeiro” (UENF), Campos dos Goytacazes, Brazil
| | | | - Raul Antonio Sperotto
- Graduate Program in Biotechnology, Universidade do Vale do Taquari, Lajeado, Brazil
- Biological Sciences and Health Center, Universidade do Vale do Taquari, Lajeado, Brazil
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3
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Zhang Y, Guo S, Jiang Z, Mao G, Ji X, He Z. Rox-DNA Functionalized Silicon Nanodots for Ratiometric Detection of Mercury Ions in Live Cells. Anal Chem 2018; 90:9796-9804. [PMID: 30014694 DOI: 10.1021/acs.analchem.8b01574] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A ratiometric fluorescent sensor for mercury ions (Hg2+) has been constructed via covalent functionalization of silicon nanodot (SiND) with Hg2+-specific 6-carboxy-X-rhodamine (Rox)-tagged DNA. For the Rox-DNA functionalized SiND, the red fluorescence of Rox can be quenched by the blue-emitting SiND in the presence of Hg2+ due to structural change in DNA, which serves as the response signal. Meawhile, the fluorescence of SiND is insensitive to Hg2+ and acts as the reference signal. The wavelength difference in the optimal emission peak is as large as 190 nm between SiND (422 nm) and Rox (612 nm), which can efficaciously exclude the interference of the two emission peaks, and facilitates dual-color visualization of Hg2+ ions. The biofunctionalization of SiND improves the acid-base stability of SiND significantly, which is favorable for its application in the intracellular environment. Accordingly, a sensitive, simple, precise and rapid method for tracing Hg2+ was proposed. The limit of detection and precision of this method for Hg2+ was 9.2 nM and 8.8% (50 nM, n = 7), respectively. The increase of Hg2+ concentration in the range of 10-1500 nM was in accordance with linearly increase of the I422/ I612 ratio. As for practical application, the recoveries in spiked human urine and serum samples were in the range of 81-107%. Moreover, this fluorescent nanosensor was utilized to the ratiometric detection of Hg2+ in HeLa cells.
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Affiliation(s)
- Yanan Zhang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences , Wuhan University , Wuhan 430072 , China
| | - Shan Guo
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences , Wuhan University , Wuhan 430072 , China
| | - Zhuoran Jiang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences , Wuhan University , Wuhan 430072 , China
| | - Guobin Mao
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences , Wuhan University , Wuhan 430072 , China
| | - Xinghu Ji
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences , Wuhan University , Wuhan 430072 , China
| | - Zhike He
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences , Wuhan University , Wuhan 430072 , China
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Buffon G, Blasi ÉADR, Rativa AGS, Lamb TI, Gastmann R, Adamski JM, Schwambach J, Ricachenevsky FK, Heringer AS, Silveira V, Lopes MCB, Sperotto RA. Unraveling Rice Tolerance Mechanisms Against Schizotetranychus oryzae Mite Infestation. FRONTIERS IN PLANT SCIENCE 2018. [PMID: 30279693 DOI: 10.1101/281733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Rice is the staple food for over half of the world's population. Infestation of Schizotetranychus oryzae (Acari: Tetranychidae) causes great losses in rice productivity. To search for rice genotypes that could better tolerate S. oryzae infestation, we evaluated morphological and production parameters in Brazilian cultivars, and identified two cultivars with contrasting responses. Leaf damage during infestation was similar for all cultivars. However, infestation in Puitá INTA-CL resulted in reduction in the number of seeds per plant, percentage of full seeds, weight of 1,000 seeds, and seed length, whereas infestation in IRGA 423 increased weight of 1,000 seeds and seed length. Reduction in seed weight per plant caused by infestation was clearly higher in Puitá INTA-CL (62%) compared to IRGA 423 (no reduction detected), thus Puitá INTA-CL was established as susceptible, and IRGA 423 as tolerant to S. oryzae infestation. Photosynthetic parameters were less affected by infestation in IRGA 423 than in Puitá INTA-CL, evidencing higher efficiency of energy absorption and use. S. oryzae infestation also caused accumulation of H2O2, decreased cell membrane integrity (indicative of cell death), and accelerated senescence in leaves of Puitá INTA-CL, while leaves of IRGA 423 presented higher levels of total phenolics compounds. We performed proteomics analysis of Puitá INTA-CL and IRGA 423 leaves after 7 days of infestation, and identified 60 differentially abundant proteins (28 more abundant in leaves of Puitá INTA-CL and 32 in IRGA 423). Proteins related to plant defense, such as jasmonate synthesis, and related to other mechanisms of tolerance such as oxidative stress, photosynthesis, and DNA structure maintenance, together with energy production and general metabolic processes, were more abundant in IRGA 423. We also detected higher levels of silicon (as amorphous silica cells) in leaves of infested IRGA 423 plants compared to Puitá INTA-CL, an element previously linked to plant defense, indicating that it could be involved in tolerance mechanisms. Taken together, our data show that IRGA 423 presents tolerance to S. oryzae infestation, and that multiple mechanisms might be employed by this cultivar. These findings could be used in biotechnological approaches aiming to increase rice tolerance to mite infestation.
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Affiliation(s)
- Giseli Buffon
- Graduate Program in Biotechnology, Universidade do Vale do Taquari, Lajeado, Brazil
| | | | | | - Thainá Inês Lamb
- Biological Sciences and Health Center, Universidade do Vale do Taquari, Lajeado, Brazil
| | - Rodrigo Gastmann
- Biological Sciences and Health Center, Universidade do Vale do Taquari, Lajeado, Brazil
| | - Janete Mariza Adamski
- Graduate Program in Botany, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Joséli Schwambach
- Graduate Program in Biotechnology, Universidade de Caxias do Sul, Caxias do Sul, Brazil
| | - Felipe Klein Ricachenevsky
- Graduate Program in Agrobiology, Universidade Federal de Santa Maria, Santa Maria, Brazil
- Graduate Program in Cell and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Angelo Schuabb Heringer
- Laboratory of Biotechnology, Universidade Estadual do Norte Fluminense "Darcy Ribeiro" (UENF), Campos dos Goytacazes, Brazil
| | - Vanildo Silveira
- Laboratory of Biotechnology, Universidade Estadual do Norte Fluminense "Darcy Ribeiro" (UENF), Campos dos Goytacazes, Brazil
- Integrative Biology Unit, Genomic and Proteomic Facility, Universidade Estadual do Norte Fluminense "Darcy Ribeiro" (UENF), Campos dos Goytacazes, Brazil
| | | | - Raul Antonio Sperotto
- Graduate Program in Biotechnology, Universidade do Vale do Taquari, Lajeado, Brazil
- Biological Sciences and Health Center, Universidade do Vale do Taquari, Lajeado, Brazil
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Singh S, Mishra AK. Unraveling of cross talk between Ca(2+) and ROS regulating enzymes in Anabaena 7120 and ntcA mutant. J Basic Microbiol 2015; 56:762-78. [PMID: 26374944 DOI: 10.1002/jobm.201500326] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 08/09/2015] [Indexed: 01/25/2023]
Abstract
In order to understand a cross talk between Ca(2+) and ROS regulating enzymes and the possible involvement of ntcA gene, Anabaena sp. PCC 7120 and its derivative ntcA mutant grown in varied levels of calcium chloride (0, 1, 10, and 100 mM) have been investigated. Scanning Electron Microscopy showed abnormal structure formation at high calcium concentration (100 mM) both in wild type and mutant. Fv /Fm values suggested that 100 mM calcium concentration was detrimental for photosynthetic apparatus. SOD, catalase, APX, GR, and peroxidase activity were found to be maximum for 100 mM and minimum for 1 mM of exogenously supplied calcium salt. NADPH contents were higher for wild type than mutant. RAPD-PCR and SDS-PAGE analysis revealed a difference in DNA as well as proteome pattern with changes in calcium chloride regime. Prominent bands of approximately 70, 33, 21, and 14 kDa expressed in the wild type served as the marker polypeptide bands under calcium supplementation. Results suggest that higher levels of calcium ion disturb the cellular homeostasis generating ROS, thereby inducing enhanced levels of antioxidative enzymes. Further, data also suggests possible involvement of ntcA gene in cross talk between calcium ion and ROS regulating enzymes.
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Affiliation(s)
- Savita Singh
- Department of Botany, Laboratory of Microbial Genetics, Banaras Hindu University, Varanasi, India
| | - Arun Kumar Mishra
- Department of Botany, Laboratory of Microbial Genetics, Banaras Hindu University, Varanasi, India
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Li X, Zhang L. Endophytic infection alleviates Pb(2+) stress effects on photosystem II functioning of Oryza sativa leaves. JOURNAL OF HAZARDOUS MATERIALS 2015; 295:79-85. [PMID: 25885166 DOI: 10.1016/j.jhazmat.2015.04.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 04/01/2015] [Accepted: 04/06/2015] [Indexed: 06/04/2023]
Abstract
The aims of this study were to examine the effect of Pb(2+) stress on the primary reaction of photosynthesis and to assess the potential benefits of endophytic infection on the Pb(2+) tolerance of rice seedlings. Rice inoculated with an endophytic fungus (E+) and non-inoculated (E-) were subjected to 0, 50, 100, 150 and 200 μM Pb(2+). The responses to Pb(2+) stress were characterized by the analysis of Chl a fluorescence. A comparison of E- with E+ rice seedlings, as evaluated by their performance index (PI(ABS) and PI(tot)), revealed the inhibitory effects of Pb(2+) on photosystem II (PSII) connectivity, the oxygen evolving complex (OEC), and on the J step of the induction curves, which is associated with an inhibition of electron transport from the quinone acceptor Q(A) to Q(B). Furthermore, the changes of the donor and the acceptor parameters of PSII were greater in E- than in E+ under Pb(2+) stress. These observations suggest that the efficiency and stability of PSII are markedly affected by Pb(2+) stress, and the photosynthetic energy conservation in E+ was more effective than in E-. We showed that endophytic infection plays an important role in enhancing the photosynthetic mechanism of rice seedlings exposed to Pb(2+) stress.
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Affiliation(s)
- Xuemei Li
- College of Chemistry and Life Science, Shenyang Normal University, Shenyang 110034, PR China.
| | - Lihong Zhang
- Environmental Science Department of Liaoning University,Shenyang 110036, PR China.
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Grégoire DS, Poulain AJ. A little bit of light goes a long way: the role of phototrophs on mercury cycling. Metallomics 2014; 6:396-407. [DOI: 10.1039/c3mt00312d] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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