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Souza PVL, Hou LY, Sun H, Poeker L, Lehman M, Bahadar H, Domingues-Junior AP, Dard A, Bariat L, Reichheld JP, Silveira JAG, Fernie AR, Timm S, Geigenberger P, Daloso DM. Plant NADPH-dependent thioredoxin reductases are crucial for the metabolism of sink leaves and plant acclimation to elevated CO 2. Plant Cell Environ 2023. [PMID: 37267089 DOI: 10.1111/pce.14631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 05/05/2023] [Accepted: 05/13/2023] [Indexed: 06/04/2023]
Abstract
Plants contain three NADPH-thioredoxin reductases (NTR) located in the cytosol/mitochondria (NTRA/B) and the plastid (NTRC) with important metabolic functions. However, mutants deficient in all NTRs remained to be investigated. Here, we generated and characterised the triple Arabidopsis ntrabc mutant alongside with ntrc single and ntrab double mutants under different environmental conditions. Both ntrc and ntrabc mutants showed reduced growth and substantial metabolic alterations, especially in sink leaves and under high CO2 (HC), as compared to the wild type. However, ntrabc showed higher effective quantum yield of PSII under both constant and fluctuating light conditions, altered redox states of NADH/NAD+ and glutathione (GSH/GSSG) and lower potential quantum yield of PSII in sink leaves in ambient but not high CO2 concentrations, as compared to ntrc, suggesting a functional interaction between chloroplastic and extra-chloroplastic NTRs in photosynthesis regulation depending on leaf development and environmental conditions. Our results unveil a previously unknown role of the NTR system in regulating sink leaf metabolism and plant acclimation to HC, while it is not affecting full plant development, indicating that the lack of the NTR system can be compensated, at least to some extent, by other redox mechanisms.
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Affiliation(s)
- Paulo V L Souza
- LabPlant, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Brazil
| | - Liang-Yu Hou
- Ludwig-Maximilians-University Munich, Planegg-Martinsried, Germany
| | - Hu Sun
- University of Rostock, Rostock, Germany
| | - Louis Poeker
- Ludwig-Maximilians-University Munich, Planegg-Martinsried, Germany
| | - Martin Lehman
- Ludwig-Maximilians-University Munich, Planegg-Martinsried, Germany
| | - Humaira Bahadar
- LabPlant, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Brazil
| | | | - Avilien Dard
- Laboratoire Génome et Développement des Plantes, Unité Mixte de Recherche 5096, Centre National de la Recherche Scientifique, Université de Perpignan Via Domitia, Perpignan, France
| | - Laetitia Bariat
- Laboratoire Génome et Développement des Plantes, Unité Mixte de Recherche 5096, Centre National de la Recherche Scientifique, Université de Perpignan Via Domitia, Perpignan, France
| | - Jean-Philippe Reichheld
- Laboratoire Génome et Développement des Plantes, Unité Mixte de Recherche 5096, Centre National de la Recherche Scientifique, Université de Perpignan Via Domitia, Perpignan, France
| | | | | | | | | | - Danilo M Daloso
- LabPlant, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Brazil
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Souza RS, Resende MFS, Ferreira LCA, Ferraz RS, Araújo MVV, Bastos CV, Silveira JAG, Moreira TF, Meneses RM, Carvalho AU, Leme FOP, Facury Filho EJ. Monitoring bovine tick fever on a dairy farm: An economic proposal for rational use of medications. J Dairy Sci 2021; 104:5643-5651. [PMID: 33663816 DOI: 10.3168/jds.2020-19504] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 12/21/2020] [Indexed: 11/19/2022]
Abstract
In this study, we evaluated the monitoring of tick fever (TF) in a Brazilian dairy farm in the Minas Gerais state, Brazil, from July 10 to August 4, 2018. We aimed to identify diagnostic and treatment flaws in the protocol adopted by the farm, and to establish a novel and accurate TF monitoring protocol based on precision dairy farming and rational use of antimicrobials and antiparasitic drugs, while evaluating the economic benefits of the proposed strategy. We monitored TF in 395 heifer calves aged between 3 and 14 mo. According to the farm's standard protocol, all calves with an increase of 0.5°C in rectal temperature compared with the previous week's measurement were treated for Anaplasma spp. and Babesia spp. Blood smears were collected from the tail tip of the treated calves. During the last week of the study, we prepared blood smears of all calves regardless of treatment indication. Economic analysis was performed. The results indicated that at least 56.86% (261/459) of the calves did not require treatment for TF, whereas only 23.09% (106/459) had treatment indications. Negative blood smears (45.97%; 211/459) indicated the possibility of calves being affected by another disease or a condition that was not being adequately treated or those not necessarily sick. These results demonstrate the excessive use of medications, representing a direct economic loss, in addition to potentially favoring the occurrence of resistance to antimicrobials. In contrast, 9.42% (26/276) of calves had no treatment indication based on rectal temperature but had treatment indications based on blood smears. Only 5.73% (42/735) of blood smears had co-infection with hemopathogens, and none had triple co-infection. Therefore, we proposed the monitoring of TF using rectal temperature and microscopic analysis. If implemented, this strategy would result in a direct annual savings of approximately $22,638.96 (77.99%) related to medication for the treatment of TF. Therefore, implementing the proposed protocol would be cheaper than treatment based only on rectal temperatures. The currently implemented TF protocols overestimate the occurrence of TF, resulting in overtreatment. Thus, implementing a TF monitoring protocol based on a microscopy tool is justified, with benefits including rational use of medication, potential to generate savings, and reduced morbidity and mortality rates, in addition to enabling other diagnoses.
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Affiliation(s)
- R S Souza
- Department of Veterinary Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Minas Gerais, 31270-901, Brazil
| | - M F S Resende
- Department of Preventive Veterinary Medicine, Veterinary School, Universidade Federal de Minas Gerais, Minas Gerais, 31270-901, Brazil
| | - L C A Ferreira
- Department of Veterinary Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Minas Gerais, 31270-901, Brazil
| | - R S Ferraz
- Department of Veterinary Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Minas Gerais, 31270-901, Brazil
| | - M V V Araújo
- Department of Veterinary Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Minas Gerais, 31270-901, Brazil
| | - C V Bastos
- Department of Preventive Veterinary Medicine, Veterinary School, Universidade Federal de Minas Gerais, Minas Gerais, 31270-901, Brazil
| | - J A G Silveira
- Department of Parasitology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Minas Gerais, 31270-901, Brazil
| | - T F Moreira
- Department of Veterinary Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Minas Gerais, 31270-901, Brazil
| | - R M Meneses
- Department of Veterinary Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Minas Gerais, 31270-901, Brazil
| | - A U Carvalho
- Department of Veterinary Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Minas Gerais, 31270-901, Brazil
| | - F O P Leme
- Department of Veterinary Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Minas Gerais, 31270-901, Brazil
| | - E J Facury Filho
- Department of Veterinary Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Minas Gerais, 31270-901, Brazil.
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3
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Estevam LGTM, Fonseca Junior AA, Silvestre BT, Hemetrio NS, Almeida LR, Oliveira MM, Silva SM, Ribeiro MFB, Silveira JAG. Seven years of evaluation of ectoparasites and vector-borne pathogens among ring-tailed coatis in an urban park in southeastern Brazil. Vet Parasitol Reg Stud Reports 2020; 21:100442. [PMID: 32862904 DOI: 10.1016/j.vprsr.2020.100442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 07/16/2020] [Accepted: 07/26/2020] [Indexed: 11/19/2022]
Abstract
Wild animals have been recognized as potential reservoirs of vector-borne pathogens. Proximity between these animals and urban areas increases the need to know which pathogens these are and whether they can infect domestic animals and humans. In Mangabeiras Municipal Park in Belo Horizonte, Brazil, coatis live near the urban area, which is mainly occupied by human residents and their domestic animals. Therefore, the objective of this study was to detect, through molecular and direct methods, the presence of ectoparasites and hemoparasites in coatis. A total of 216 samples were collected, of which 209 samples were from first-captures and seven were from recaptures. The following parasites were found: ticks of the genus Amblyomma, lice of the species Neotrichodectes pallidus and fleas of the species Rhopalopsyllus lutzi lutzi and Ctenocephalides felis felis. All the samples were negative for the family Anaplasmataceae and the species Leishmania sp. and Trypanosoma cruzi. The hemoparasites Trypanosoma evansi, Hepatozoon procyonis, Babesia sp. and Sarcocystis neurona were found. The area of the present study is not endemic for T. evansi, which therefore suggests that these coatis may be acting as reservoirs or sentinels of this parasite. This finding is of great epidemiological importance and should be investigated more closely. Thus, this study showed that there is a great variety of pathogens in the park that transit among coatis and, probably, among other animals that inhabit or live close to the park.
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Affiliation(s)
- L G T M Estevam
- Departament of Parasitology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - A A Fonseca Junior
- National Agriculture and Livestock Laboratory - LANAGRO, Ministry of Agriculture, Livestock and Food Supply - MAPA, Minas Gerais, Brazil
| | - B T Silvestre
- Departament of Parasitology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - N S Hemetrio
- City Hall of Belo Horizonte, Municipal Parks Foundation, Minas Gerais, Brazil
| | - L R Almeida
- Departament of Parasitology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - M M Oliveira
- Departament of Imunology, Microbiology and Parasitology, Institute of Biomedical Sciences, Universidade Federal de Uberlândia, Minas Gerais, Brazil
| | - S M Silva
- Departament of Imunology, Microbiology and Parasitology, Institute of Biomedical Sciences, Universidade Federal de Uberlândia, Minas Gerais, Brazil
| | - M F B Ribeiro
- Departament of Parasitology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - J A G Silveira
- Departament of Parasitology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
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Alencar VTCB, Lobo AKM, Carvalho FEL, Silveira JAG. High ammonium supply impairs photosynthetic efficiency in rice exposed to excess light. Photosynth Res 2019; 140:321-335. [PMID: 30694432 DOI: 10.1007/s11120-019-00614-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 01/08/2019] [Indexed: 06/09/2023]
Abstract
Mechanisms involving ammonium toxicity, excess light, and photosynthesis are scarcely known in plants. We tested the hypothesis that high NH4+ supply in presence of high light decreases photosynthetic efficiency of rice plants, an allegedly tolerant species. Mature rice plants were previously supplied with 10 mM NH4+ or 10 mM NO3- and subsequently exposed to 400 µmol m-2 s-1 (moderate light-ML) or 2000 µmol m-2 s-1 (high light-HL) for 8 h. HL greatly stimulated NH4+ accumulation in roots and in a minor extent in leaves. These plants displayed significant delay in D1 protein recovery in the dark, compared to nitrate-supplied plants. These responses were related to reduction of both PSII and PSI quantum efficiencies and induction of non-photochemical quenching. These changes were also associated with higher limitation in the donor side and lower restriction in the acceptor side of PSI. This later response was closely related to prominent decrease in stomatal conductance and net CO2 assimilation that could have strongly affected the energy balance in chloroplast, favoring ATP accumulation and NPQ induction. In parallel, NH4+ induced a strong increase in the electron flux to photorespiration and, inversely, it decreased the flux to Rubisco carboxylation. Overall, ammonium supply negatively interacts with excess light, possibly by enhancing ammonium transport towards leaves, causing negative effects on some photosynthetic steps. We propose that high ammonium supply to rice combined with excess light is capable to induce strong delay in D1 protein turnover and restriction in stomatal conductance, which might have contributed to generalized disturbances on photosynthetic efficiency.
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Affiliation(s)
- V T C B Alencar
- Departamento de Bioquímica e Biologia Molecular, Laboratório de Metabolismo de Plantas, Universidade Federal do Ceará, Av. Humberto Monte 2825, Campus do Pici, Bl. 907, CP 6020, Fortaleza, Ceará, CEP 60451-970, Brazil
| | - A K M Lobo
- Departamento de Bioquímica e Biologia Molecular, Laboratório de Metabolismo de Plantas, Universidade Federal do Ceará, Av. Humberto Monte 2825, Campus do Pici, Bl. 907, CP 6020, Fortaleza, Ceará, CEP 60451-970, Brazil
| | - F E L Carvalho
- Departamento de Bioquímica e Biologia Molecular, Laboratório de Metabolismo de Plantas, Universidade Federal do Ceará, Av. Humberto Monte 2825, Campus do Pici, Bl. 907, CP 6020, Fortaleza, Ceará, CEP 60451-970, Brazil
| | - J A G Silveira
- Departamento de Bioquímica e Biologia Molecular, Laboratório de Metabolismo de Plantas, Universidade Federal do Ceará, Av. Humberto Monte 2825, Campus do Pici, Bl. 907, CP 6020, Fortaleza, Ceará, CEP 60451-970, Brazil.
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5
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Rêgo WMF, Costa JGL, Baraviera RCA, Pinto LV, Bessa GL, Lopes REN, Silveira JAG, Vitor RWA. Genetic diversity of Toxoplasma gondii isolates obtained from free-living wild birds rescued in Southeastern Brazil. Int J Parasitol Parasites Wildl 2018; 7:432-438. [PMID: 30479944 PMCID: PMC6240670 DOI: 10.1016/j.ijppaw.2018.11.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 10/31/2018] [Accepted: 11/04/2018] [Indexed: 11/30/2022]
Abstract
Recent studies carried out in Brazil have shown that strains from the same Toxoplasma gondii genotype can infect humans, domestic animals (dogs and cats) and animals slaughtered for human consumption (pigs, sheep, goats, and chickens), suggesting a common infection route. However, little is known about the importance of free-living wild birds within this epidemiological context. The objective of this work was to isolate, genotype, and evaluate the virulence for mice of new isolates of T. gondii obtained from free-living wild birds from the state of Minas Gerais, Southeastern Brazil. From August 2016 to June 2017, T. gondii was isolated from the hearts and brains collected from 6 out of 45 free-living wild birds, namely, a roadside hawk (Rupornis magnirostris), a campo flicker (Colaptes campestris), a southern caracara (Caracara plancus) and a tropical screech-owl (Megascops choliba), all rescued in Belo Horizonte. One isolate was obtained from a toco toucan (Ramphastos toco), rescued in Cristiano Otoni, and another was obtained from southern caracara, rescued in Santa Luzia. Five different genotypes were identified by PCR-RFLP. A unique genotype was shared in two different isolates obtained from a southern caracara and a toco toucan. This genotype has never been previously described in any other host or place. Three isolates were classified as of intermediary virulence and three isolates as avirulent for mice. The combined analysis of alleles ROP18/ROP5 (a serine/threonine kinase, and a polymorphic pseudokinase, respectively) was effective in determining the virulence of five of all the isolates with the exception of that from R. magnirostris. Atypical isolates of T. gondii obtained from free-living wild birds rescued in the state of Minas Gerais share the same genotypes of strains that infect humans, domestic animals, and animals slaughtered for human consumption.
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Affiliation(s)
- W M F Rêgo
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (ICB-UFMG), CEP, 31270-901, Belo Horizonte, MG, Brazil
| | - J G L Costa
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (ICB-UFMG), CEP, 31270-901, Belo Horizonte, MG, Brazil
| | - R C A Baraviera
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (ICB-UFMG), CEP, 31270-901, Belo Horizonte, MG, Brazil
| | - L V Pinto
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (ICB-UFMG), CEP, 31270-901, Belo Horizonte, MG, Brazil
| | - G L Bessa
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (ICB-UFMG), CEP, 31270-901, Belo Horizonte, MG, Brazil
| | - R E N Lopes
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (ICB-UFMG), CEP, 31270-901, Belo Horizonte, MG, Brazil
| | - J A G Silveira
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (ICB-UFMG), CEP, 31270-901, Belo Horizonte, MG, Brazil
| | - R W A Vitor
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (ICB-UFMG), CEP, 31270-901, Belo Horizonte, MG, Brazil
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6
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Lima Neto MC, Cerqueira JVA, da Cunha JR, Ribeiro RV, Silveira JAG. Cyclic electron flow, NPQ and photorespiration are crucial for the establishment of young plants of Ricinus communis and Jatropha curcas exposed to drought. Plant Biol (Stuttg) 2017; 19:650-659. [PMID: 28403551 DOI: 10.1111/plb.12573] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 04/06/2017] [Indexed: 05/11/2023]
Abstract
Although plant physiological responses to drought have been widely studied, the interaction between photoprotection, photorespiration and antioxidant metabolism in water-stressed plants is scarcely addressed. This study aimed to evaluate the physiological adjustments preserving photosynthesis and growth in two plant species with different tolerance to drought: Jatropha curcas and Ricinus communis. We measured stress indicators, gas exchange, photochemistry of PSII and PSI, antioxidant enzymes, cyclic electron flow and photorespiration. Physiological stress indicators associated with reduction in growth confirmed R. communis as sensitive and J. curcas as tolerant to drought. Drought induced loss of photosynthesis in R. communis, whereas J. curcas maintained higher leaf gas exchange and photochemistry under drought. In addition, J. curcas showed higher dissipation of excess energy and presented higher cyclic electron flow when exposed to drought. Although none of these mechanisms have been triggered in R. communis, this species showed increases in photorespiration. R. communis displayed loss of Rubisco content while the Rubisco relative abundance did not change in J. curcas under drought. Accordingly, the in vivo maximum Rubisco carboxylation rate (Vcmax ) and the maximum photosynthetic electron transport rate driving RuBP regeneration (Jmax ) were less affected in J. curcas. Both species displayed an efficient antioxidant mechanism by increasing activities of ascorbate peroxidase (APX) and superoxide dismutase (SOD). Overall, we suggest that the modulation of different photoprotective mechanisms is crucial to mitigate the effects caused by excess energy, maintaining photosynthetic apparatus efficiency and promoting the establishment of young plants of these two species under drought.
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Affiliation(s)
- M C Lima Neto
- UNESP - Biosciences Institute, São Paulo State University - UNESP, Coastal Campus, Praça Infante Dom Henrique s/n, São Vicente, São Paulo, Brazil
| | - J V A Cerqueira
- Department of Biochemistry and Molecular Biology, Plant Metabolism Laboratory, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - J R da Cunha
- Department of Biochemistry and Molecular Biology, Plant Metabolism Laboratory, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - R V Ribeiro
- Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - J A G Silveira
- Department of Biochemistry and Molecular Biology, Plant Metabolism Laboratory, Federal University of Ceará, Fortaleza, Ceará, Brazil
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Silva EN, Silveira JAG, Rodrigues CRF, Viégas RA. Physiological adjustment to salt stress in Jatropha curcas is associated with accumulation of salt ions, transport and selectivity of K+, osmotic adjustment and K+/Na+ homeostasis. Plant Biol (Stuttg) 2015; 17:1023-9. [PMID: 25865670 DOI: 10.1111/plb.12337] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 04/08/2015] [Indexed: 05/26/2023]
Abstract
This study assessed the capacity of Jatropha curcas to physiologically adjust to salinity. Seedlings were exposed to increasing NaCl concentrations (25, 50, 75 and 100 mm) for 15 days. Treatment without NaCl was adopted as control. Shoot dry weight was strongly reduced by NaCl, reaching values of 35% to 65% with 25 to 100 mm NaCl. The shoot/root ratio was only affected with 100 mm NaCl. Relative water content (RWC) increased only with 100 mm NaCl, while electrolyte leakage (EL) was much enhanced with 50 mm NaCl. The Na(+) transport rate to the shoot was more affected with 50 and 100 mm NaCl. In parallel, Cl(-) transport rate increased with 75 and 100 mm NaCl, while K(+) transport rate fell from 50 mm to 100 mm NaCl. In roots, Na(+) and Cl(-) transport rates fell slightly only in 50 mm (to Na(+)) and 50 and 100 mm (to Cl(-)) NaCl, while K(+) transport rate fell significantly with increasing NaCl. In general, our data demonstrate that J. curcas seedlings present changes in key physiological processes that allow this species to adjust to salinity. These responses are related to accumulation of Na(+) and Cl(-) in leaves and roots, K(+)/Na(+) homeostasis, transport of K(+) and selectivity (K-Na) in roots, and accumulation of organic solutes contributing to osmotic adjustment of the species.
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Affiliation(s)
- E N Silva
- Faculdade de Educação, Ciências e Letras do Sertão, Central, Universidade Estadual do Ceará, Quixadá, Ceará, Brazil
| | - J A G Silveira
- Departamento de Bioquímica e Biologia Molecular/Instituto Nacional de Ciência e Tecnologia em Salinidade (INCTsal/CNPq), Universidade Federal do Ceará, Fortaleza, Ceará, Brazil
| | - C R F Rodrigues
- Departamento de Ecologia, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
- Faculdade Leão Sampaio, Juazeiro do Norte, CE, Brazil
| | - R A Viégas
- Departamento de Engenharia Florestal da UFPB, Universidade Federal de Campina Grande, Patos, Paraíba, Brazil
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8
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Lima Neto MC, Lobo AKM, Martins MO, Fontenele AV, Silveira JAG. Dissipation of excess photosynthetic energy contributes to salinity tolerance: a comparative study of salt-tolerant Ricinus communis and salt-sensitive Jatropha curcas. J Plant Physiol 2014; 171:23-30. [PMID: 24094996 DOI: 10.1016/j.jplph.2013.09.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 09/04/2013] [Accepted: 09/05/2013] [Indexed: 05/24/2023]
Abstract
The relationships between salt tolerance and photosynthetic mechanisms of excess energy dissipation were assessed using two species that exhibit contrasting responses to salinity, Ricinus communis (tolerant) and Jatropha curcas (sensitive). The salt tolerance of R. communis was indicated by unchanged electrolyte leakage (cellular integrity) and dry weight in leaves, whereas these parameters were greatly affected in J. curcas. The leaf Na+ content was similar in both species. Photosynthesis was intensely decreased in both species, but the reduction was more pronounced in J. curcas. In this species biochemical limitations in photosynthesis were more prominent, as indicated by increased C(i) values and decreased Rubisco activity. Salinity decreased both the V(cmax) (in vivo Rubisco activity) and J(max) (maximum electron transport rate) more significantly in J. curcas. The higher tolerance in R. communis was positively associated with higher photorespiratory activity, nitrate assimilation and higher cyclic electron flow. The high activity of these alternative electron sinks in R. communis was closely associated with a more efficient photoprotection mechanism. In conclusion, salt tolerance in R. communis, compared with J. curcas, is related to higher electron partitioning from the photosynthetic electron transport chain to alternative sinks.
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Affiliation(s)
- Milton C Lima Neto
- Departamento de Bioquímica e Biologia Molecular/INCTsal-CNPq/MCT, Laboratório de Metabolismo de Plantas, Universidade Federal do Ceará, CP 6004, CEP 60455-970 Fortaleza, Ceará, Brazil
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9
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Ribeiro CW, Carvalho FEL, Rosa SB, Alves-Ferreira M, Andrade CMB, Ribeiro-Alves M, Silveira JAG, Margis R, Margis-Pinheiro M. Modulation of genes related to specific metabolic pathways in response to cytosolic ascorbate peroxidase knockdown in rice plants. Plant Biol (Stuttg) 2012; 14:944-955. [PMID: 22686276 DOI: 10.1111/j.1438-8677.2012.00587.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
As a central component of the hydrogen peroxide detoxifying system in plant cells, ascorbate peroxidases (APX) play an essential role in the control of intracellular reactive oxygen species (ROS) levels. To characterise the function of cytosolic APX isoforms (OsAPX1 and OsAPX2) in the mechanisms of plant defence, OsAPX1/2 knockdown rice plants were previously obtained. OsAPX1/2 knockdown plants (APx1/2s) exhibited a normal phenotype and development, even though they showed a global reduction of APX activity and increased hydrogen peroxide accumulation. To understand how rice plants compensate for the deficiency of cytosolic APX, expression and proteomic analyses were performed to characterise the global expression pattern of the APx1/2s mutant line compared with non-transformed plants. Our results strongly suggest that deficiencies in cytosolic APX isoforms markedly alter expression of genes associated with several key metabolic pathways, especially of genes involved in photosynthesis and antioxidant defence. These metabolic changes are compensatory because central physiological processes such as photosynthesis and growth were similar to non-transformed rice plants. Our analyses showed modulation of groups of genes and proteins related to specific metabolic pathways. Among the differentially expressed genes, the largest number corresponded to those with catalytic activity. Genes related to oxidative stress, carbohydrate metabolism, photosynthesis and transcription factor-encoding genes were also modulated. These results represent an important step toward understanding of the role played by cytosolic APX isoforms and hydrogen peroxide in the regulation of metabolism by redox modulation in monocots.
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Affiliation(s)
- C W Ribeiro
- Biotechnology Center, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
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Silveira JAG, Rabelo EML, Ribeiro MFB. Molecular detection of tick-borne pathogens of the family Anaplasmataceae in Brazilian brown brocket deer (Mazama gouazoubira, Fischer, 1814) and marsh deer (Blastocerus dichotomus, Illiger, 1815). Transbound Emerg Dis 2011; 59:353-60. [PMID: 22136597 DOI: 10.1111/j.1865-1682.2011.01278.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Deer are important natural reservoir hosts of Anaplasmataceae. The present study used nested PCR and nucleotide sequencing to evaluate the occurrence of Anaplasmataceae species in 23 free-living and six captive specimens of the cervids Mazama gouazoubira and Blastocerus dichotomus in Minas Gerais State, Brazil. Blood samples were tested for the presence of Ehrlichia and Anaplasma spp. using nPCR assays and sequencing of the msp4, msp1 and 16S rRNA genes. The identity of each sequence was confirmed by comparison with sequences available from GenBank using BLAST software. Of the animals investigated, 93.1% (27/29) were infected with haemoparasites including Anaplasma marginale (79.3%), Ehrlichia chaffeensis (3.4%), Anaplasma bovis (3.4%) and Anaplasma spp. (assigned to A. platys and A. phagocytophilum) (17.2%). Co-infection occurred in 20% (6/29) of the deer examined. Four (13.8%) were infected with A. marginale and Anaplasma sp., one (3.4%) was infected with A. marginale and E. chaffeensis, and one (3.4%) was infected with A. marginale and A. bovis. The results of the present study suggest that cross-protection does not occur in these deer. Immunological cross-reaction occurs when sera are tested diagnostically because these bacteria are closely related taxonomically, reinforcing the importance of molecular diagnosis followed by nucleotide sequencing.
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Affiliation(s)
- J A G Silveira
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil
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