Time filter

Source Type

Mehta A.,Embrapa Recursos Geneticos e Biotecnologia | Lopez-Maury L.,University of Seville | Florencio F.J.,University of Seville
Journal of Proteomics | Year: 2014

Cyanobacteria represent the largest and most diverse group of prokaryotes capable of performing oxygenic photosynthesis and are frequently found in environments contaminated with heavy metals. Several studies have been performed in these organisms in order to better understand the effects of metals such as Zn, Cd, Cu, Ni and Co. In Synechocystis sp. PCC 6803, genes involved in Ni, Co, Cu and Zn resistance have been reported. However, proteomic studies for the identification of proteins modulated by heavy metals have not been carried out. In the present work, we have analyzed the proteomic pattern alterations of the cyanobacterium Synechocystis sp. PCC 6803 in response to Ni, Co and Cd in order to identify the metabolic processes affected by these metals. We show that some proteins are commonly regulated in response to the different metal ions, including ribulose1,5-bisphosphate carboxylase and the periplasmic iron-binding protein FutA2, while others, such as chaperones, were specifically induced by each metal. We also show that the main processes affected by the metals are carbon metabolism and photosynthesis, since heavy metals affect proteins required for the correct functioning of these activities. Biological significance: This is the first report on the proteomic profile of Synechocystis sp. PCC 6803 wild type and mutant strains for the identification of proteins affected by the heavy metals Ni, Co and Cd. We have identified proteins commonly responsive to all three metals and also chaperones specifically modulated by each metal. Our data also supports previous studies that suggest the existence of additional sensor systems for Co. © 2014 Elsevier B.V.

da Silva T.L.,University of Sao Paulo | Scherwinski-Pereira J.E.,Embrapa Recursos Geneticos e Biotecnologia
Pesquisa Agropecuaria Brasileira | Year: 2011

The objective of this work was to evaluate in vitro storage of Piper aduncum and P. hispidinervum under slow-growth conditions. Shoots were stored at low temperatures (10, 20 and 25°C), and the culture medium was supplemented with osmotic agents (sucrose and mannitol - at 1, 2 and 3%) and abiscisic acid - ABA (0, 0.5, 1.0, 2.0 and 3.0 mg L-1). After six-months of storage, shoots were evaluated for survival and regrowth. Low temperature at 20°C was effective for the in vitro conservation of P. aduncum and P. hispidinervum shoots. In vitro cultures maintained at 20°C on MS medium showed 100% survival with slow-growth shoots. The presence of mannitol or ABA, in the culture medium, negatively affected shoot growth, which is evidenced by the low rate of recovered shoots.

Aragao F.J.L.,Embrapa Recursos Geneticos e Biotecnologia | Nogueira E.O.P.L.,Embrapa Recursos Geneticos e Biotecnologia | Tinoco M.L.P.,Embrapa Recursos Geneticos e Biotecnologia | Faria J.C.,Embrapa Arroz e Feijao
Journal of Biotechnology | Year: 2013

Golden mosaic of common bean is caused by the Bean golden mosaic virus (BGMV). The disease is one of the greatest constraints on bean production in Latin America and causes significant yield losses. The RNAi concept was explored to silence the rep (AC1) viral gene and a transgenic bean line immune to BGMV upon inoculation at high pressure was previously generated. Identification of the transgene insert confirmed the presence of a single locus corresponding to two intact copies of the RNAi cassette in opposite orientation and three intact copies of the AtAhas gene. It is flanked by Phaseolus genomic sequences and interspersed by one nuclear and three chloroplastic genomic sequences. Southern analyses showed that the transgenes were structurally stable for eight self-pollinated generations and after backcrosses with a non transgenic commercial variety. Transgene expression analyses revealed similar levels of siRNA in leaves of transgenic plants cultivated under field conditions in three distinct regions. siRNA were also analyzed during seed development in common bean transgenic plants. siRNA signals were also detected in seeds, albeit at significantly lower levels than those observed in leaves, and could not be detected in seeds cooked during 10. min. This information is relevant to demonstrate that GM beans are free of siRNA signals after cooking and therefore suitable for human consumption. Additionally, characterization of the locus where the transgene was integrated in the common bean genome provides a valuable tool to trace this GM bean material in the field and in the market. © 2013 Elsevier B.V.

Simon M.F.,Embrapa Recursos Geneticos e Biotecnologia | Pennington T.,Royal Botanic Garden Edinburgh
International Journal of Plant Sciences | Year: 2012

A recent controversy concerns whether plant traits that are assumed to be adaptations to fire originally evolved in response to selective factors other than fire. We contribute to this debate by investigating the evolution of the endemic woody flora of the fire-prone Cerrado of central Brazil, the most species-rich savanna in the world. We review evidence from dated phylogenies and show that Cerrado lineages started to diversify less than 10 million years ago. These Cerrado lineages are characterized by fire-resistant traits such as thick, corky bark and root sprouting, which have been considered to have evolved as adaptations to drought or nutrient-deficient soils. However, the fact that the lineages carrying these features arose coincident with the rise to dominance of flammable C4 grasses and expansion of the savanna biome worldwide, and postdating the earlier origin of seasonal climates and the nutrient-poor, acid Cerrado soils suggests that such traits should be considered as adaptations to fire regimes. The nature of these features as adaptations to fire is further suggested by their absence or poor development in related lineages found in fire-free environments with similar edaphic conditions to the Cerrado and by their repeated independent origin in diverse lineages. We present evidence to demonstrate that the evolutionary barrier to entry to the Cerrado is a weak one, presumably because of the ease of evolution of the necessary adaptations to fire regimes for lineages inhabiting neighboring fire-free biomes. © 2012 by The University of Chicago. All rights reserved.

Lopes R.M.,University of Brasilia | Da Silveira Agostini-Costa T.,Embrapa Recursos Geneticos e Biotecnologia | Gimenes M.A.,Embrapa Recursos Geneticos e Biotecnologia | Silveira D.,University of Brasilia
Journal of Agricultural and Food Chemistry | Year: 2011

Arachis hypogaea, known as the peanut, is native to South America. Peanut contains several active components including flavonoids, phenolic acids, phytosterols, alkaloids, and stilbenes. Some therapeutic effects have been reported for peanut seed extracts, such as antioxidative, antibacterial, antifungal, and anti-inflammatory activities. This paper aims to give an overview of the chemical composition, focusing on secondary metabolites, and of the biological activity of A. hypogaea, to stimulate new studies about species of the Arachis genus. © 2011 American Chemical Society.

Paulini F.,Embrapa Recursos Geneticos e Biotecnologia | Paulini F.,University of Brasilia | Melo E.O.,Embrapa Recursos Geneticos e Biotecnologia
Reproduction in Domestic Animals | Year: 2011

Ovarian physiology is controlled by endocrine and paracrine signals, and the transforming growth factor β (TGFβ) superfamily has a pivotal role in this control. The Bone morphogenetic protein 15 (BMP15) and Growth differentiation factor 9 (GDF9) genes are relevant members of the TGFβ superfamily that encode proteins secreted by the oocytes into the ovarian follicles. Through a paracrine signalling pathway, these factors induce the follicular somatic cells to undergo mitosis and differentiation during follicular development. These events are controlled by a mutually dependent and coordinated fashion during the formation of the granulosa cell layers. Many studies have contributed to our knowledge concerning the paracrine factors acting within the follicular environment, especially regarding GDF9 and BMP15. We aimed to review the relevant contributions of these two genes to animal reproductive physiology. © 2010 Blackwell Verlag GmbH.

Bonatto C.C.,University of Brasilia | Silva L.P.,Embrapa Recursos Geneticos e Biotecnologia
Journal of the Science of Food and Agriculture | Year: 2015

BACKGROUND: Chocolate authentication is a key aspect of quality control and safety. Matrix-assisted laser desorption ionization time-of flight (MALDI-TOF) mass spectrometry (MS) has been demonstrated to be useful for molecular profiling of cells, tissues, and even food. The present study evaluated if MALDI-TOF MS analysis on low molecular mass profile may classify chocolate samples according to the cocoa content. RESULTS: The molecular profiles of seven processed commercial chocolate samples were compared by using MALDI-TOF MS. Some ions detected exclusively in chocolate samples corresponded to the metabolites of cocoa or other constituents. This method showed the presence of three distinct clusters according to confectionery and sensorial features of the chocolates and was used to establish a mass spectra database. Also, novel chocolate samples were evaluated in order to check the validity of the method and to challenge the database created with the mass spectra of the primary samples. Thus, the method was shown to be reliable for clustering unknown samples into the main chocolate categories. CONCLUSION: Simple sample preparation of the MALDI-TOF MS approach described will allow the surveillance and monitoring of constituents during the molecular profiling of chocolates. © 2014 Society of Chemical Industry.

Citadin C.T.,Embrapa Recursos Geneticos e Biotecnologia | Cruz A.R.R.,Embrapa Recursos Geneticos e Biotecnologia | Aragao F.J.L.,Embrapa Recursos Geneticos e Biotecnologia
Plant Cell Reports | Year: 2013

Key message: Here we present the development of cowpea lines tolerant to a herbicide from imidazoline class (imazapyr). Plants presented tolerance to fourfold the commercial recommended dose for weed control. Cowpea is one of the most important and widely cultivated legumes in many parts of the world. Its cultivation is drastically affected by weeds, causing damages during growth and development of plants, competing for light, nutrients and water. Consequently, weed control is critical, especially using no-tillage farming systems. In tropical regions, no-till farming is much easier with the use of herbicides to control weeds. This study was conducted to evaluate the possibility of obtaining transgenic cowpea plants resistant to imidazolinone, which would facilitate weed control during the summer season. The biolistic process was used to insert a mutated acetohydroxyacid synthase coding gene (Atahas) which confers tolerance to imazapyr. The transgene integration was confirmed by Southern blot analysis. Out of ten lines tested for tolerance to 100 g ha-1 imazapyr, eight presented some tolerance. One line (named 59) revealed high herbicide tolerance and developmental growth comparable to non-transgenic plants. This line was further tested for tolerance to higher herbicide concentrations and presented tolerance to 400 g ha-1 imazapyr (fourfold the commercial recommended dose) with no visible symptoms. Line 59 will be the foundation for generating imidazolinone-tolerant cowpea varieties, which will facilitate cultivation of this crop in large areas. © 2013 Springer-Verlag Berlin Heidelberg.

Pastore J.F.B.,Embrapa Recursos Geneticos e Biotecnologia
Phytotaxa | Year: 2013

Names of Polygalaceae used by Vellozo in his Flora Fluminensis are reviewed within the current floristic context of the State of Rio de Janeiro and its bordering areas, as well as the morphological evidence provided. Nearly all of Vellozo's names are placed as synonyms of older names, except for a new combination for Polygala disperma as Bredemeyera and Polygala appendiculata which is considered a valid name for P. leptocaulis. All names not yet typified are here lectotypified, except for B. autranii. © 2013 Magnolia Press.

Pastore J.F.B.,Embrapa Recursos Geneticos e Biotecnologia
Phytotaxa | Year: 2014

This paper is a review of all Polygalaceae material on which the treatments of the family by Saint-Hilaire and Moquin- Tandon in 1828 and Saint-Hilaire in 1829 were based. It includes type designation for the names of all new taxa there proposed, except for Polygala paludosa var. ambigua. Some of the Saint-Hilaire and Moquin-Tandon's names which were omitted in several Neotropical Polygalaceous treatments are here reviewed. Therefore, one of them, Polygala sellowiana, is here re-established as the correct name for the species better known as P. sabulosa. More detailed information is provided for Saint-Hilaire's Polygalaceae collection. © 2014 Magnolia Press.

Loading Embrapa Recursos Geneticos e Biotecnologia collaborators
Loading Embrapa Recursos Geneticos e Biotecnologia collaborators