Embrapa Recursos Geneticos e Biotecnologia


Embrapa Recursos Geneticos e Biotecnologia

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Ferreira M.C.,University of Brasilia | Vieira D.L.M.,Embrapa Recursos Geneticos e Biotecnologia
Ecological Engineering | Year: 2017

Topsoil translocation has been effective for the restoration of plant communities, but until recently this method had not been used for tropical dry forest restoration. We tested different methods of topsoil deposition for restoring a dry forest on an abandoned limestone quarry. We also tested the effects of irrigation during the first dry season after topsoil deposition. The study was conducted in the Federal District of Brazil. A 2.1-ha area was cleared of vegetation, and the topsoil from that site was deposited on an exotic pasture field 1.4 km away. First, a secondary forest was clear-cut, and the first 30 cm of topsoil were removed and translocated. The soil was transported in dump trucks to the deposition site, which had been scarified in advance, and deposited by either forming 1.25-m-tall mounds or by leveling the soil into a 40-cm or 20-cm deep layer using a hydraulic excavator. The seed bank and the availability of root and stem fragments in the soil were both surveyed. The origin of the regenerants was categorized as either from seed or resprouting. We estimated vegetation cover for each life form, and measured all trees and lianas. After six months, 74% of the tree individuals and 60% of the liana individuals came from resprouting. Ruderal herbs and shrubs germinated from seeds. After 28 months, there were 51 species of trees, 8 species of lianas, 12 species of shrubs, and 34 species of herbs in the deposition treatments. The three deposition treatments were thickly covered with herbaceous/shrubby species, and had nine times the number of species (44 vs. 5) and five times the tree density (1.17 ind./m2 vs. 0.25 ind./m2) as the non-deposition control. Tree survival was relatively high in both the non-irrigated and irrigated treatments. The total cost of topsoil translocation was 9604 USD, and the output was 0.43 ha deposited/ha excavated when forming mounds of soil, 5951 USD and output of 0.75 when leveling to a 40-cm layer, and 3551 USD and 1.5 for a 20-cm layer of deposited material. However, deposition and transportation costs are fixed costs of establishing a new quarry that can be deducted from the total cost of restoration. Topsoil translocation was effective in kick-starting the succession process of a tropical dry forest. © 2017 Elsevier B.V.

Mendes G.C.,Federal University of Viçosa | Reis P.A.B.,Federal University of Viçosa | Calil I.P.,Federal University of Viçosa | Carvalho H.H.,Federal University of Viçosa | And 2 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2013

Prolonged endoplasmic reticulum and osmotic stress synergistically activate the stress-induced N-rich protein-mediated signaling that transduces a cell death signal by inducing GmNAC81 (GmNAC6) in soybean. To identify novel regulators of the stress-induced programmed cell death (PCD) response, we screened a two-hybrid library for partners of GmNAC81. We discovered another member of the NAC (NAM-ATAF1,2-CUC2) family, GmNAC30, which binds to GmNAC81 in the nucleus of plant cells to coordinately regulate common target promoters that harbor the core cis-regulatory element TGTG[TGC]. We found that GmNAC81 and GmNAC30 can function either as transcriptional repressors or activators and cooperate to enhance the transcriptional regulation of common target promoters, suggesting that heterodimerization may be required for the full regulation of gene expression. Accordingly, GmNAC81 and GmNAC30 display overlapping expression profiles in response to multiple environmental and developmental stimuli. Consistent with a role in PCD, GmNAC81 and GmNAC30 bind in vivo to and transactivate hydrolytic enzyme promoters in soybean protoplasts. A GmNAC81/GmNAC30 binding site is located in the promoter of the caspase-1-like vacuolar processing enzyme (VPE) gene, which is involved in PCD in plants. We demonstrated that the expression of GmNAC81 and GmNAC30 fully transactivates the VPE gene in soybean protoplasts and that this transactivation was associated with an increase in caspase-1-like activity. Collectively, our results indicate that the stress-induced GmNAC30 cooperates with GmNAC81 to activate PCD through the induction of the cell death executioner VPE.

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.

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.

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.

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