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Made available in DSpace on 2022-04-28T19:44:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-11-15 Agaves have been used for centuries as a feedstock in dryland areas for fibers, food, and beverages, and have enormous potential for biofuel production. Brazil is the world's largest producer of Agave fiber (sisal). However, since the development of synthetic fibers, the national investment in Agave research has decreased drastically, leading to the cessation of the country's breeding programs. What is left of the Brazilian elite cultivars were planted at a germplasm bank in the middle of the semiarid. Surprisingly, after 7 years of abandonment, the plants were still healthy and did not show any clear signs of stress. Here, we aimed to investigate how these plants managed to cope with this environment and the molecular basis of their biomass traits. We assembled the transcriptomic atlas of Agave sisalana, Agave fourcroydes, and Agave hybrid 11648 ((A. amaniensis x A. angustifolia) x A. amaniensis). We observed that the cultivars activated a highly overlapping set of stress-response genes, which were the most expressed transcripts. Also, raffinose was detected at high concentrations, possibly acting as an osmolyte, though differences at its biosynthesis have been found depending on cultivar. Finally, we observed differences in recalcitrance that could be attributed to lignin composition and its biosynthetic pathway. Our data contribute new insights that can help molecular breeders to correspond to emerging expectations for Agave as biorenewables feedstocks for dryland areas. Laboratório de Genômica e BioEnergia Departamento de Genética Evolução Microbiologia e Imunologia UNICAMP Departamento de Bioprocessos e Biotecnologia Faculdade de Ciências Agronômicas UNESP Departamento de Botânica Instituto de Biociências USP Laboratório de Anatomia Vegetal Departamento de Biologia Vegetal UNICAMP Empresa Brasileira de Pesquisa Agropecuária - Algodão EMBRAPA High-Throughput Sequencing Facility School of Medicine UNC Centro para Computação em Engenharia e Ciências UNICAMP Departamento de Bioprocessos e Biotecnologia Faculdade de Ciências Agronômicas UNESP

Sisal is a common name for different plant varieties in the genus Agave (especially Agave sisalana) used for high-quality natural leaf fiber extraction. Despite the economic value of these plants, we still lack information about the diversity of viruses (virome) in non-tequilana species from the genus Agave. In this work, by associating RNA and DNA deep sequencing we were able to identify 25 putative viral species infecting A. sisalana, A. fourcroydes, and Agave hybrid 11648, including one strain of Cowpea Mild Mottle Virus (CPMMV) and 24 elements likely representing new viruses. Phylogenetic analysis indicated they belong to at least six viral families: Alphaflexiviridae, Betaflexiviridae, Botourmiaviridae, Closteroviridae, Partitiviridae, Virgaviridae, and three distinct unclassified groups. We observed higher viral taxa richness in roots when compared to leaves and stems. Furthermore, leaves and stems are very similar diversity-wise, with a lower number of taxa and dominance of a single viral species. Finally, approximately 50% of the identified viruses were found in all Agave organs investigated, which suggests that they likely produce a systemic infection. This is the first metatranscriptomics study focused on viral identification in species from the genus Agave. Despite having analyzed symptomless individuals, we identified several viruses supposedly infecting Agave species, including organ-specific and systemic species. Surprisingly, some of these putative viruses are probably infecting microorganisms composing the plant microbiota. Altogether, our results reinforce the importance of unbiased strategies for the identification and monitoring of viruses in plant species, including those with asymptomatic phenotypes.

Background Plant pathogenesis related-1 (PR-1) proteins belong to the CAP superfamily and have been characterized as markers of induced defense against pathogens. Moniliophthora perniciosa and Moniliophthora roreri are hemibiotrophic fungi that respectively cause the witches’ broom disease and frosty pod rot in Theobroma cacao. Interestingly, a large number of plant PR-1-like genes are present in the genomes of both species and many are up-regulated during the biotrophic interaction. In this study, we investigated the evolution of PR-1 proteins from 22 genomes of Moniliophthora isolates and 16 other Agaricales species, performing genomic investigation, phylogenetic reconstruction, positive selection search and gene expression analysis. Results Phylogenetic analysis revealed conserved PR-1 genes (PR-1a, b, d, j), shared by many Agaricales saprotrophic species, that have diversified in new PR-1 genes putatively related to pathogenicity in Moniliophthora (PR-1f, g, h, i), as well as in recent specialization cases within M. perniciosa biotypes (PR-1c, k, l) and M. roreri (PR-1n). PR-1 families in Moniliophthora with higher evolutionary rates exhibit induced expression in the biotrophic interaction and positive selection clues, supporting the hypothesis that these proteins accumulated adaptive changes in response to host–pathogen arms race. Furthermore, although previous work showed that MpPR-1 can detoxify plant antifungal compounds in yeast, we found that in the presence of eugenol M. perniciosa differentially expresses only MpPR-1e, k, d, of which two are not linked to pathogenicity, suggesting that detoxification might not be the main function of most MpPR-1. Conclusions Based on analyses of genomic and expression data, we provided evidence that the evolution of PR-1 in Moniliophthora was adaptive and potentially related to the emergence of the parasitic lifestyle in this genus. Additionally, we also discuss how fungal PR-1 proteins could have adapted from basal conserved functions to possible roles in fungal pathogenesis.

Viral infections pose intense burdens to healthcare systems and global economies. The correct diagnosis of viral diseases represents a crucial step towards effective treatments and control. Biosensors have been successfully implemented as accessible and accurate detection tests for some of the most important viruses. While most biosensors are based on physical or chemical interactions of cell-free components, the complexity of living microorganisms holds a poorly explored potential for viral detection in the face of the advances of synthetic biology. Indeed, cell-based biosensors have been praised for their versatility and economic attractiveness, however, yeast platforms for viral disease diagnostics are still limited to indirect antibody recognition. Here we propose a novel strategy for viral detection in Saccharomyces cerevisiae, which combines the transductive properties of G Protein-Coupled Receptors (GPCRs) with the Yeast Surface Display (YSD) of specific enzymes enrolled in the viral recognition process. The GPCR/YSD complex might allow for active virus detection through a modulated signal activated by a GPCR agonist, whose concentration correlates to the viral titer. Additionally, we explore this methodology in a case study for the detection of highly pathogenic coronaviruses that share the same cell receptor upon infection (i.e. the Angiotensin-Converting Enzyme 2, ACE2), as a conceptual example of the potential of the GPCR/YSD strategy for the diagnosis of COVID-19.

Made available in DSpace on 2020-12-10T20:10:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-08-14 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Serrapilheira Institute Background The need to restructure the world's energy matrix based on fossil fuels and mitigate greenhouse gas emissions stimulated the development of new biobased technologies for renewable energy. One promising and cleaner alternative is the use of second-generation (2G) fuels, produced from lignocellulosic biomass sugars. A major challenge on 2G technologies establishment is the inefficient assimilation of the five-carbon sugar xylose by engineeredSaccharomyces cerevisiaestrains, increasing fermentation time. The uptake of xylose across the plasma membrane is a critical limiting step and the budding yeastS. cerevisiaeis not designed with a broad transport system and regulatory mechanisms to assimilate xylose in a wide range of concentrations present in 2G processes. Results Assessing diverse microbiomes such as the digestive tract of plague insects and several decayed lignocellulosic biomasses, we isolated several yeast species capable of using xylose. Comparative fermentations selected the yeastCandida sojaeas a potential source of high-affinity transporters. Comparative genomic analysis elects four potential xylose transporters whose properties were evaluated in the transporter null EBY.VW4000 strain carrying the xylose-utilizing pathway integrated into the genome. While the traditional xylose transporter Gxf1 allows an improved growth at lower concentrations (10 g/L), strains containing Cs3894 and Cs4130 show opposite responses with superior xylose uptake at higher concentrations (up to 50 g/L). Docking and normal mode analysis of Cs4130 and Gxf1 variants pointed out important residues related to xylose transport, identifying key differences regarding substrate translocation comparing both transporters. Conclusions Considering that xylose concentrations in second-generation hydrolysates can reach high values in several designed processes, Cs4130 is a promising novel candidate for xylose uptake. Here, we demonstrate a novel eukaryotic molecular transporter protein that improves growth at high xylose concentrations and can be used as a promising target towards engineering efficient pentose utilization in yeast. Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Biorenewable Natl Lab LNBR, BR-13083100 Campinas, SP, Brazil Univ Campinas UNICAMP, Inst Biol, Genet & Mol Biol Grad Program, Campinas, Brazil Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Biosci Natl Lab LNBio, BR-13083970 Campinas, SP, Brazil Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Synchrotron Light Lab LNLS, BR-13083970 Campinas, SP, Brazil Sao Paulo State Univ, UNESP, Dept Phys, Inst Biosci Humanities & Exact Sci, BR-15054000 Sao Jose Do Rio Preto, SP, Brazil Sao Paulo State Univ, UNESP, Dept Phys, Inst Biosci Humanities & Exact Sci, BR-15054000 Sao Jose Do Rio Preto, SP, Brazil FAPESP: 2017/08519-6 FAPESP: 2017/05078-9 FAPESP: 2018/00888-5 CNPq: 430291/2018-3 CAPES: 001 Serrapilheira Institute: Serra1708-16205

Plants recognize a wide variety of microbial molecules to detect and respond to potential invaders. Recognition of Microbe-Associated Molecular Patterns (MAMPs) by cell surface receptors initiate a cascade of biochemical responses that include, among others, ion fluxes across the plasma membrane. A consequence of such event is a decrease in the concentration of extracellular H(+) ions, which can be experimentally detected in plant cell suspensions as a shift in the pH of the medium. Thus, similarly to reactive oxygen species (ROS) accumulation, phosphorylation of MAP kinases and induction of defense-related genes, MAMP-induced medium alkalinization can be used as a proxy for the activation of plant immune responses. Here, we describe a detailed protocol for the measurement of medium alkalinization of tobacco BY-2 cell suspensions upon treatment with two different MAMPs: chitohexamers derived from fungal cell walls (NAG6; N-acetylglucosamine) and the flagellin epitope flg22, found in the bacterial flagellum. This method provides a reliable and fast platform to access MAMP-Triggered Immunity (MTI) in tobacco cell suspensions and can be easily adapted to other plant species as well as to other MAMPs.

Background Second-generation ethanol production is a clean bioenergy source with potential to mitigate fossil fuel emissions. The engineering of Saccharomyces cerevisiae for xylose utilization is an essential step towards the production of this biofuel. Though xylose isomerase (XI) is the key enzyme for xylose conversion, almost half of the XI genes are not functional when expressed in S. cerevisiae. To date, protein misfolding is the most plausible hypothesis to explain this phenomenon. Results This study demonstrated that XI from the bacterium Propionibacterium acidipropionici becomes functional in S. cerevisiae when co-expressed with GroEL-GroES chaperonin complex from Escherichia coli. The developed strain BTY34, harboring the chaperonin complex, is able to efficiently convert xylose to ethanol with a yield of 0.44 g ethanol/g xylose. Furthermore, the BTY34 strain presents a xylose consumption rate similar to those observed for strains carrying the widely used XI from the fungus Orpinomyces sp. In addition, the tetrameric XI structure from P. acidipropionici showed an elevated number of hydrophobic amino acid residues on the surface of protein when compared to XI commonly expressed in S. cerevisiae. Conclusions Based on our results, we elaborate an extensive discussion concerning the uncertainties that surround heterologous expression of xylose isomerases in S. cerevisiae. Probably, a correct folding promoted by GroEL-GroES could solve some issues regarding a limited or absent XI activity in S. cerevisiae. The strains developed in this work have promising industrial characteristics, and the designed strategy could be an interesting approach to overcome the non-functionality of bacterial protein expression in yeasts. Electronic supplementary material The online version of this article (10.1186/s12896-017-0389-7) contains supplementary material, which is available to authorized users.

Here, we report the genome assembly of a Saccharomyces cerevisiae SA1-derived haploid (FMY097) indigenous strain isolated from a Brazilian ethanol distillery. FMY097 was recently reported to be a highly aldehyde-resistant strain capable of producing bioethanol in the presence of up to 40 mM furfural and 80 mM 5-hydroxymethylfurfural.

Background The Ceratocystis genus harbors a large number of phytopathogenic fungi that cause xylem parenchyma degradation and vascular destruction on a broad range of economically important plants. Ceratocystis cacaofunesta is a necrotrophic fungus responsible for lethal wilt disease in cacao. The aim of this work is to analyze the genome of C. cacaofunesta through a comparative approach with genomes of other Sordariomycetes in order to better understand the molecular basis of pathogenicity in the Ceratocystis genus. Results We present an analysis of the C. cacaofunesta genome focusing on secreted proteins that might constitute pathogenicity factors. Comparative genome analyses among five Ceratocystidaceae species and 23 other Sordariomycetes fungi showed a strong reduction in gene content of the Ceratocystis genus. However, some gene families displayed a remarkable expansion, in particular, the Phosphatidylinositol specific phospholipases-C (PI-PLC) family. Also, evolutionary rate calculations suggest that the evolution process of this family was guided by positive selection. Interestingly, among the 82 PI-PLCs genes identified in the C. cacaofunesta genome, 70 genes encoding extracellular PI-PLCs are grouped in eight small scaffolds surrounded by transposon fragments and scars that could be involved in the rapid evolution of the PI-PLC family. Experimental secretome using LC–MS/MS validated 24% (86 proteins) of the total predicted secretome (342 proteins), including four PI-PLCs and other important pathogenicity factors. Conclusion Analysis of the Ceratocystis cacaofunesta genome provides evidence that PI-PLCs may play a role in pathogenicity. Subsequent functional studies will be aimed at evaluating this hypothesis. The observed genetic arsenals, together with the analysis of the PI-PLC family shown in this work, reveal significant differences in the Ceratocystis genome compared to the classical vascular fungi, Verticillium and Fusarium. Altogether, our analyses provide new insights into the evolution and the molecular basis of plant pathogenicity. Electronic supplementary material The online version of this article (10.1186/s12864-018-4440-4) contains supplementary material, which is available to authorized users.

Crop diseases caused by fungi constitute one of the most important problems in agriculture, posing a serious threat to food security [1]. To establish infection, phytopathogens interfere with plant immune responses [2, 3]. However, strategies to promote virulence employed by fungal pathogens, especially non-model organisms, remain elusive [4], mainly because fungi are more complex and difficult to study when compared to the better-characterized bacterial pathogens. Equally incomplete is our understanding of the birth of microbial virulence effectors. Here, we show that the cacao pathogen Moniliophthora perniciosa evolved an enzymatically inactive chitinase (MpChi) that functions as a putative pathogenicity factor. MpChi is among the most highly expressed fungal genes during the biotrophic interaction with cacao and encodes a chitinase with mutations that abolish its enzymatic activity. Despite the lack of chitinolytic activity, MpChi retains substrate binding specificity and prevents chitin-triggered immunity by sequestering immunogenic chitin fragments. Remarkably, its sister species M. roreri encodes a second non-orthologous catalytically impaired chitinase with equivalent function. Thus, a class of conserved enzymes independently evolved as putative virulence factors in these fungi. In addition to unveiling a strategy of host immune suppression by fungal pathogens, our results demonstrate that the neofunctionalization of enzymes may be an evolutionary pathway for the rise of new virulence factors in fungi. We anticipate that analogous strategies are likely employed by other pathogens. Fiorin et al. demonstrate that two fungal pathogens of cacao independently evolved catalytically dead chitinases that bind to chitin and prevent elicitation of plant immunity. The study exemplifies how pathogens may evolve effectors by repurposing the functions of enzymes that are conserved throughout evolution.

The pathogenic fungi Moniliophthora perniciosa causes Witches’ Broom Disease (WBD) of cacao. The structure of MpPR-1i, a protein expressed by M. perniciosa when it infects cacao, are presented. This is the first reported de novo structure determined by single-wavelength anomalous dispersion phasing upon soaking with selenourea. Each monomer has flexible loop regions linking the core alpha-beta-alpha sandwich topology that comprise ~50% of the structure, making it difficult to generate an accurate homology model of the protein. MpPR-1i is monomeric in solution but is packed as a high ~70% solvent content, crystallographic heptamer. The greatest conformational flexibility between monomers is found in loops exposed to the solvent channel that connect the two longest strands. MpPR-1i lacks the conserved CAP tetrad and is incapable of binding divalent cations. MpPR-1i has the ability to bind lipids, which may have roles in its infection of cacao. These lipids likely bind in the palmitate binding cavity as observed in tablysin-15, since MpPR-1i binds palmitate with comparable affinity as tablysin-15. Further studies are required to clarify the possible roles and underlying mechanisms of neutral lipid binding, as well as their effects on the pathogenesis of M. perniciosa so as to develop new interventions for WBD.

The development of biocatalysts capable of fermenting xylose, a five-carbon sugar abundant in lignocellulosic biomass, is a key step to achieve a viable production of second-generation ethanol. In this work, a robust industrial strain of Saccharomyces cerevisiae was modified by the addition of essential genes for pentose metabolism. Subsequently, taken through cycles of adaptive evolution with selection for optimal xylose utilization, strains could efficiently convert xylose to ethanol with a yield of about 0.46 g ethanol/g xylose. Though evolved independently, two strains carried shared mutations: amplification of the xylose isomerase gene and inactivation of ISU1, a gene encoding a scaffold protein involved in the assembly of iron-sulfur clusters. In addition, one of evolved strains carried a mutation in SSK2, a member of MAPKKK signaling pathway. In validation experiments, mutating ISU1 or SSK2 improved the ability to metabolize xylose of yeast cells without adaptive evolution, suggesting that these genes are key players in a regulatory network for xylose fermentation. Furthermore, addition of iron ion to the growth media improved xylose fermentation even by non-evolved cells. Our results provide promising new targets for metabolic engineering of C5-yeasts and point to iron as a potential new additive for improvement of second-generation ethanol production.

Made available in DSpace on 2018-12-11T17:30:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-10-13 Made available in DSpace on 2018-12-11T17:30:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-10-13 Made available in DSpace on 2018-12-11T17:30:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-10-13 Termites are considered one of the most efficient decomposers of lignocelluloses on Earth due to their ability to produce, along with its microbial symbionts, a repertoire of carbohydrate-active enzymes (CAZymes). Recently, a set of Pro-oxidant, Antioxidant, and Detoxification enzymes (PAD) were also correlated with the metabolism of carbohydrates and lignin in termites. The lower termite Coptotermes gestroi is considered the main urban pest in Brazil, causing damage to wood constructions. Recently, analysis of the enzymatic repertoire of C. gestroi unveiled the presence of different CAZymes. Because the gene profile of CAZy/PAD enzymes endogenously synthesized by C. gestroi and also by their symbiotic protists remains unclear, the aim of this study was to explore the eukaryotic repertoire of these enzymes in worker and soldier castes of C. gestroi. Our findings showed that worker and soldier castes present similar repertoires of CAZy/PAD enzymes, and also confirmed that endo-glucanases (GH9) and beta-glucosidases (GH1) were the most important glycoside hydrolase families related to lignocellulose degradation in both castes. Classical cellulases such as exo-glucanases (GH7) and endo-glucanases (GH5 and GH45), as well as classical xylanases (GH10 and GH11), were found in both castes only taxonomically related to protists, highlighting the importance of symbiosis in C. gestroi. Moreover, our analysis revealed the presence of Auxiliary Activity enzyme families (AAs), which could be related to lignin modifications in termite digestomes. In conclusion, this report expanded the knowledge on genes and proteins related to CAZy/PAD enzymes from worker and soldier castes of lower termites, revealing new potential enzyme candidates for second-generation biofuel processes. Laborat�rio Nacional de Ci�ncia e Tecnologia do Bioetanol (CTBE) Centro Nacional de Pesquisa em Energia e Materiais (CNPEM) Departamento de Bioqu�mica e Biologia Tecidual Universidade Estadual de Campinas (UNICAMP) Laborat�rio de Gen�mica e Express�o Universidade Estadual de Campinas (UNICAMP) Centro de Hematologia e Hemoterapia (Hemocentro) Universidade Estadual de Campinas (UNICAMP) Laborat�rio de Espectrometria de Massas Laborat�rio Nacional de Bioci�ncias (LNBIO) Centro Nacional de Pesquisa em Energia e Materiais (CNPEM) Departamento de Biologia Instituto de Bioci�ncias Universidade Estadual Paulista (UNESP) Departamento de Biologia Instituto de Bioci�ncias Universidade Estadual Paulista (UNESP)

The draft genome of Salmonella enterica serovar Enteritidis phage type 4 (PT4) strain IOC4647/2004, isolated from a poultry farm in São Paulo state, was obtained with high-throughput Illumina sequencing platform, generating 4,173,826 paired-end reads with 251 bp. The assembly of 4,804,382 bp in 27 scaffolds shows strong similarity to other S . Enteritidis strains.

The main goals of the present study included the screening and identification of cellulase producing wild yeasts, isolated from samples collected from different Brazilian biomes. They were selected according to their capabilities of degrading carboxymethyl cellulose (CMC) and micro-crystalline cellulose (SERVACEL ® ), as single carbon sources in solid medium. After the step of solid medium selection, yeast cells were grown in liquid medium containing cellulose (SERVACEL ® ); in shake flasks at temperature of 30°C and 150 rpm agitation for 288 h. Three specific activities were evaluated: endoglucanase (CMCase), total activity (filter paper activity), and cellobiase. From a total of 390 strains of wild yeasts previously isolated, 16 strains performed cellulose hydrolysis, verified by the colorless halo in the solid medium. Among these 16 strains, 5 stood out as presenting higher levels of enzyme activity. The following step, screening in liquid medium, indicated only one strain as a potential producer of cellulases, named as AAJ6, for which the highest hydrolytic activity on carboxymethyl cellulose (0.33 U/ml) and filter paper (0.039 U/ml) was recorded. Afterwards, this wild yeast strain (AAJ6) was molecularly identified by sequencing the ITS1-5.8S-ITS2 and D1/D2 domains of the subunit (26 S) ribosomal DNA. Sequencing resulted in the identification of this strain as yeast-like fungus Acremonium strictum . Keywords: Acremonium strictum , screening, identification, yeast-like, cellulases

Background Drought is a widespread limiting factor in coffee plants. It affects plant development, fruit production, bean development and consequently beverage quality. Genetic diversity for drought tolerance exists within the coffee genus. However, the molecular mechanisms underlying the adaptation of coffee plants to drought are largely unknown. In this study, we compared the molecular responses to drought in two commercial cultivars (IAPAR59, drought-tolerant and Rubi, drought-susceptible) of Coffea arabica grown in the field under control (irrigation) and drought conditions using the pyrosequencing of RNA extracted from shoot apices and analysing the expression of 38 candidate genes. Results Pyrosequencing from shoot apices generated a total of 34.7 Mbp and 535,544 reads enabling the identification of 43,087 clusters (41,512 contigs and 1,575 singletons). These data included 17,719 clusters (16,238 contigs and 1,575 singletons) exclusively from 454 sequencing reads, along with 25,368 hybrid clusters assembled with 454 sequences. The comparison of DNA libraries identified new candidate genes (n = 20) presenting differential expression between IAPAR59 and Rubi and/or drought conditions. Their expression was monitored in plagiotropic buds, together with those of other (n = 18) candidates genes. Under drought conditions, up-regulated expression was observed in IAPAR59 but not in Rubi for CaSTK1 (protein kinase), CaSAMT1 (SAM-dependent methyltransferase), CaSLP1 (plant development) and CaMAS1 (ABA biosynthesis). Interestingly, the expression of lipid-transfer protein (nsLTP) genes was also highly up-regulated under drought conditions in IAPAR59. This may have been related to the thicker cuticle observed on the abaxial leaf surface in IAPAR59 compared to Rubi. Conclusions The full transcriptome assembly of C. arabica, followed by functional annotation, enabled us to identify differentially expressed genes related to drought conditions. Using these data, candidate genes were selected and their differential expression profiles were confirmed by qPCR experiments in plagiotropic buds of IAPAR59 and Rubi under drought conditions. As regards the genes up-regulated under drought conditions, specifically in the drought-tolerant IAPAR59, several corresponded to orphan genes but also to genes coding proteins involved in signal transduction pathways, as well as ABA and lipid metabolism, for example. The identification of these genes should help advance our understanding of the genetic determinism of drought tolerance in coffee. Electronic supplementary material The online version of this article (doi:10.1186/s12870-016-0777-5) contains supplementary material, which is available to authorized users.

Ventricular hypertrophy is one of the major myocardial responses to pressure overload (PO). Most studies on early myocardial response focus on the days or even weeks after induction of hypertrophic stimuli. Since mechanotransduction pathways are immediately activated in hearts undergoing increased work load, it is reasonable to infer that the myocardial gene program may be regulated in the first few hours. In the present study, we monitored the expression of some genes previously described in the context of myocardial hypertrophic growth by using the Northern blot technique, to estimate the mRNA content of selected genes in rat myocardium for the periods 1, 3, 6, 12 and 48 h after PO stimuli. Results revealed an immediate switch in the expression of genes encoding alpha and beta isoforms of myosin heavy chain, and up-regulation of the cardiac isoform of alpha actin. We also detected transitory gene regulation as the increase in mitochondrial cytochrome c oxidase 1 gene expression, parallel to down-regulation of genes encoding sarco(endo)plasmic reticulum Ca(+2) ATPase and sodium-calcium exchanger. Taken together, these results indicate that initial myocardial responses to increased work load include alterations in the contractile properties of sarcomeres and transitory adjustment of mitochondrial bioenergetics and calcium availability.

Theobroma cacao is a tropical understory tree that is one of the most important perennial crops in agriculture. Treasured by ancient civilizations in Mesoamerica for over 3,000 years, the cocoa bean now supports a multibillion-dollar industry that is involved in the production and commercialization of chocolate, a treat appreciated worldwide. The cacao tree is originally from the Amazon rainforest and is currently grown in more than 50 countries throughout the humid tropics, serving as a major source of income for over 40 million people. Each year, more than 3 million tons of cocoa beans are produced, mostly by smallholder farmers in areas of high biodiversity. Notably, the cacao tree does not require direct sunlight and naturally grows under the canopy of other, taller trees. This characteristic often encourages farmers to preserve existing forests and to plant additional trees to shelter their cacao plants [1], thereby reducing the environmental impacts of cacao cultivation. Despite its great importance, the cacao tree is affected by a number of untreatable diseases that reduce fruit production and threaten our global supply of cacao. Among them, witches’ broom disease (WBD) stands out as one of the most severe problems that affect this crop, accounting for production losses of up to 90%.

Background Eucalyptus species are the most widely planted hardwood species in the world and are renowned for their rapid growth and adaptability. In Brazil, one of the most widely grown Eucalyptus cultivars is the fast-growing Eucalyptus urophylla x Eucalyptus grandis hybrid. In a previous study, we described a chemical characterization of these hybrids when subjected to flavonoid supplementation on 2 distinct timetables, and our results revealed marked differences between the wood composition of the treated and untreated trees. Results In this work, we report the transcriptional responses occurring in these trees that may be related to the observed chemical differences. Gene expression was analysed through mRNA-sequencing, and notably, compared to control trees, the treated trees display differential down-regulation of cell wall formation pathways such as phenylpropanoid metabolism as well as differential expression of genes involved in sucrose, starch and minor CHO metabolism and genes that play a role in several stress and environmental responses. We also performed enzymatic hydrolysis of wood samples from the different treatments, and the results indicated higher sugar contents and glucose yields in the flavonoid-treated plants. Conclusions Our results further illustrate the potential use of flavonoids as a nutritional complement for modifying Eucalyptus wood, since, supplementation with flavonoids alters its chemical composition, gene expression and increases saccharification probably as part of a stress response. Electronic supplementary material The online version of this article (doi:10.1186/s12870-014-0301-8) contains supplementary material, which is available to authorized users.

Background High-throughput screening of physical, genetic and chemical-genetic interactions brings important perspectives in the Systems Biology field, as the analysis of these interactions provides new insights into protein/gene function, cellular metabolic variations and the validation of therapeutic targets and drug design. However, such analysis depends on a pipeline connecting different tools that can automatically integrate data from diverse sources and result in a more comprehensive dataset that can be properly interpreted. Results We describe here the Integrated Interactome System (IIS), an integrative platform with a web-based interface for the annotation, analysis and visualization of the interaction profiles of proteins/genes, metabolites and drugs of interest. IIS works in four connected modules: (i) Submission module, which receives raw data derived from Sanger sequencing (e.g. two-hybrid system); (ii) Search module, which enables the user to search for the processed reads to be assembled into contigs/singlets, or for lists of proteins/genes, metabolites and drugs of interest, and add them to the project; (iii) Annotation module, which assigns annotations from several databases for the contigs/singlets or lists of proteins/genes, generating tables with automatic annotation that can be manually curated; and (iv) Interactome module, which maps the contigs/singlets or the uploaded lists to entries in our integrated database, building networks that gather novel identified interactions, protein and metabolite expression/concentration levels, subcellular localization and computed topological metrics, GO biological processes and KEGG pathways enrichment. This module generates a XGMML file that can be imported into Cytoscape or be visualized directly on the web. Conclusions We have developed IIS by the integration of diverse databases following the need of appropriate tools for a systematic analysis of physical, genetic and chemical-genetic interactions. IIS was validated with yeast two-hybrid, proteomics and metabolomics datasets, but it is also extendable to other datasets. IIS is freely available online at: http://www.lge.ibi.unicamp.br/lnbio/IIS/.

Avian pathogenic Escherichia coli (APEC) infections are responsible for significant losses in the poultry industry worldwide. The disease might present as different local infections or as septicemia. Here, we present the draft genome sequences of three Brazilian APEC strains isolated from different kinds of infections. The availability of these APEC genome sequences is important for gaining a thorough understanding of the genomic features of E. coli , particularly those of this pathotype.

Made available in DSpace on 2014-12-03T13:11:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-11-11Bitstream added on 2014-12-03T13:22:47Z : No. of bitstreams: 1 WOS000327221600081.pdf: 1259635 bytes, checksum: 94a7f854e23462a4f12622699cd436d4 (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Centre de Cooperation Internationale en Recherche Agronomique pour le Developpement Plant genomes are massively invaded by transposable elements (TEs), many of which are located near host genes and can thus impact gene expression. In flowering plants, TE expression can be activated (de-repressed) under certain stressful conditions, both biotic and abiotic, as well as by genome stress caused by hybridization. In this study, we examined the effects of these stress agents on TE expression in two diploid species of coffee, Coffea canephora and C. eugenioides, and their allotetraploid hybrid C. arabica. We also explored the relationship of TE repression mechanisms to host gene regulation via the effects of exonized TE sequences. Similar to what has been seen for other plants, overall TE expression levels are low in Coffea plant cultivars, consistent with the existence of effective TE repression mechanisms. TE expression patterns are highly dynamic across the species and conditions assayed here are unrelated to their classification at the level of TE class or family. In contrast to previous results, cell culture conditions per se do not lead to the de-repression of TE expression in C. arabica. Results obtained here indicate that differing plant drought stress levels relate strongly to TE repression mechanisms. TEs tend to be expressed at significantly higher levels in non-irrigated samples for the drought tolerant cultivars but in drought sensitive cultivars the opposite pattern was shown with irrigated samples showing significantly higher TE expression. Thus, TE genome repression mechanisms may be finely tuned to the ideal growth and/or regulatory conditions of the specific plant cultivars in which they are active. Analysis of TE expression levels in cell culture conditions underscored the importance of nonsense-mediated mRNA decay (NMD) pathways in the repression of Coffea TEs. These same NMD mechanisms can also regulate plant host gene expression via the repression of genes that bear exonized TE sequences. Univ Estadual Paulista, Univ Estadual Paulista Julio de Mesquita Filho, Dept Biol, Sao Jose do Rio Preto, Brazil Georgia Inst Technol, Sch Biol, Atlanta, GA 30332 USA Univ Estadual Londrina, Dept Biol Geral, Londrina, Brazil Empresa Brasileira Pesquisa Agr Recursos Genet &, Brasilia, DF, Brazil Ctr Cooperat Int Rech Agron Dev, UMR AGAP, Montpellier, France Univ Estadual Campinas, Dept Genet Evolucao & Bioagentes, Campinas, SP, Brazil Empresa Brasileira Pesquisa Agr Cafe, Brasilia, DF, Brazil PanAmer Bioinformat Inst, Santa Marta, Magdalena, Colombia Univ Estadual Paulista, Univ Estadual Paulista Julio de Mesquita Filho, Dept Biol, Sao Jose do Rio Preto, Brazil FAPESP: 08/05894-1 FAPESP: 07/55985-0

Boto, a class II transposable element, was characterized in the Moniliophthora perniciosa genome. The Boto transposase is highly similar to plant PIF-like transposases that belong to the newest class II superfamily known as PIF/Harbinger. Although Boto shares characteristics with PIF-like elements, other characteristics, such as the transposase intron position, the position and direction of the second ORF, and the footprint, indicate that Boto belongs to a novel family of the PIF/Harbinger superfamily. Southern blot analyses detected 6-12 copies of Boto in C-biotype isolates and a ubiquitous presence among the C- and S-biotypes, as well as a separation in the C-biotype isolates from Bahia State in Brazil in at least two genotypic groups, and a new insertion in the genome of a C-biotype isolate maintained in the laboratory for 6 years. In addition to PCR amplification from a specific insertion site, changes in the Boto hybridization profile after the M. perniciosa sexual cycle and detection of Boto transcripts gave further evidence of Boto activity. As an active family in the genome of M. perniciosa, Boto elements may contribute to genetic variability in this homothallic fungus. This is the first report of a PIF/Harbinger transposon in the genome of a phytopathogenic fungus.

International audience; Cotton (Gossypium) fiber is the most prevalent natural product used in the textile industry. The two major cultivated species, G. hirsutum (Gh) and G. barbadense (Gb), are allotetraploids with contrasting fiber quality properties. To better understand the molecular basis for their fiber differences, EST pyrosequencing was used to document the fiber transcriptomes at two key development stages, 10 days post anthesis (dpa), representing the peak of fiber elongation, and 22 dpa, representing the transition to secondary cell wall synthesis. The 617,000 high quality reads (89% of the total 692,000 reads) from 4 libraries were assembled into 46,072 unigenes, comprising 38,297 contigs and 7,775 singletons. Functional annotation of the unigenes together with comparative digital gene expression (DGE) revealed a diverse set of functions and processes that were partly linked to specific fiber stages. Globally, 2,770 contigs (7%) showed differential expression (>2-fold) between 10 and 22 dpa (irrespective of genotype), with 70% more highly expressed at 10 dpa, while 2,248 (6%) were differentially expressed between the genotypes (irrespective of stage). The most significant genes with differential DGE at 10 dpa included expansins and lipid transfer proteins (higher in Gb), while at 22 dpa tubulins, cellulose, and sucrose synthases showed higher expression in Gb. DGE was compared with expression data of 10 dpa-old fibers from Affymetrix microarrays. Among 543 contigs showing differential expression on both platforms, 74% were consistent in being either over-expressed in Gh (242 genes) or in Gb (161 genes). Furthermore, the unigene set served to identify 339 new SSRs and close to 21,000 inter-genotypic SNPs. Subsets of 88 SSRs and 48 SNPs were validated through mapping and added 65 new loci to a RIL genetic map. The new set of fiber ESTs and the gene-based markers complement existing available resources useful in basic and applied research for crop improvement in cotton.

The legume Glycine max (soybean) plays an important economic role in the international commodities market, with a world production of almost 260 million tons for the 2009/2010 harvest. The increase in drought events in the last decade has caused production losses in recent harvests. This fact compels us to understand the drought tolerance mechanisms in soybean, taking into account its variability among commercial and developing cultivars. In order to identify single nucleotide polymorphisms (SNPs) in genes up-regulated during drought stress, we evaluated suppression subtractive libraries (SSH) from two contrasting cultivars upon water deprivation: sensitive (BR 16) and tolerant (Embrapa 48). A total of 2,222 soybean genes were up-regulated in both cultivars. Our method identified more than 6,000 SNPs in tolerant and sensitive Brazilian cultivars in those drought stress related genes. Among these SNPs, 165 (in 127 genes) are positioned at soybean chromosome ends, including transcription factors (MYB, WRKY) related to tolerance to abiotic stress.

The Genosoja consortium is an initiative to integrate different omics research approaches carried out in Brazil. Basically, the aim of the project is to improve the plant by identifying genes involved in responses against stresses that affect domestic production, like drought stress and Asian Rust fungal disease. To do so, the project generated several types of sequence data using different methodologies, most of them sequenced by next generation sequencers. The initial stage of the project is highly dependent on bioinformatics analysis, providing suitable tools and integrated databases. In this work, we describe the main features of the Genosoja web database, including the pipelines to analyze some kinds of data (ESTs, SuperSAGE, microRNAs, subtractive cDNA libraries), as well as web interfaces to access information about soybean gene annotation and expression.

The enzyme UDP-N-acetylglucosamine pyrophosphorylase (PyroMp) from Moniliophthora perniciosa (CCMB 0257), a pathogenic fungal strain and the causative agent of the witches' broom disease in Theobroma cacao, was partially purified by precipitation with ammonium sulfate and gel filtration on Sephacryl S-200. The buffer for enzyme extraction was sodium phosphate, 0.050 mol L-1, pH 7.0, containing 1.0 mol L-1 NaCl. Response surface methodology (RSM) was used to determine the optimum pH and temperature conditions. Four different isoenzymes (PyroMp I, PyroMp II, PyroMp III and PyroMp IV) were obtained with optimal pH ranging from 6.9-8.4 and optimum temperature ranging from 28 to 68 °C. The 3D structure of pyrophosphorylase of M. perniciosa was determined by comparative modeling. The model obtained showed a good quality, possessing 78.6% of amino acids in energetically allowed regions. The model was then submitted for DM simulation and showed a good geometric quality (91.1% Ramachandran plot). The active site of the enzyme was found to be extremely well conserved. This model will be useful for developing new inhibitors against witches' broom disease. A enzima UDP-N-acetilglicosamina pirofosforilase de Moniliophthora perniciosa (CCMB 0257), o fungo patogênico causador da doença vassoura-de-bruxa do Theobroma cacao, foi parcialmente purificada por precipitação com sulfato de amônio e cromatografia de gel filtração em Sephacryl S-200. O tampão de extração da enzima foi o fosfato de sódio, 0,050 mol L-1, pH 7,0, contendo 1,0 mol L-1 de NaCl. A metodologia de superfície de resposta (MSR) foi usada para a obtenção do pH e temperatura ótima. Os resultados mostraram quatro diferentes isoenzimas (PyroMp I, PyroMp II, PyroMp III e PyroMp IV) que apresentaram pH ótimo na faixa de 6,9-8,4 e temperatura ótima variando entre 28 a 68 °C. A estrutura 3D de pirofosforilase de M. perniciosa foi obtida por modelagem comparativa. O modelo obtido mostrou uma boa qualidade, possuindo 78,6% de aminoácidos nas regiões energeticamente favoráveis. O modelo foi então submetido a simulações de dinâmica molecular (DM). O modelo apresentou uma boa qualidade geométrica após as simulações de DM (91,1% -gráfico de Ramachandran). A procura pelo sítio ativo da enzima mostrou que este é mantido extremamente conservado. Este modelo pode ser útil para desenvolvimento de inibidores contra a doença vassoura de bruxa.

A análise de sequências de transcriptase reversa (RT) é uma etapa importante para descobrir a presença de elementos transponíveis e investigar o seu papel na geração de variabilidade genética em C. perniciosa. Seqüências putativas de TR foram analisadas no genoma do fitopatógeno C. perniciosa, o agente causal da doença vassoura-de-bruxa no cacau. Um fragmento de 394 pb foi amplificado a partir do DNA genômico de diferentes isolados de C. perniciosa, pertencentes aos biótipos C, L e S e a distintas áreas geográficas. A clivagem dos produtos de PCR com diferentes enzimas de restrição e sequenciamento de vários fragmentos de TR indicou a presença de diferentes seqüências mostrando eventos de transição G:C para A:T. A análise por hibridização revelou alto número de sinais sugerindo a presença de cópias de TR com diferentes perfis entre os isolados dos biótipos C, S e L. As comparações de seqüências dos peptídeos preditos indicam uma relação próxima com a proteína TR de retrotransposons-LTR da família gypsy. Reverse transcriptase (RT) sequence analysis is an important technique used to detect the presence of transposable elements in a genome. Putative RT sequences were analyzed in the genome of the pathogenic fungus C. perniciosa, the causal agent of witches' broom disease of cocoa. A 394 bp fragment was amplified from genomic DNA of different isolates of C. perniciosa belonging to C-, L-, and S-biotypes and collected from various geographical areas. The cleavage of PCR products with restriction enzymes and the sequencing of various RT fragments indicated the presence of several sequences showing transition events (G:C to A:T). Southern blot analysis revealed high copy numbers of RT signals, forming different patterns among C-, S-, and L-biotype isolates. Sequence comparisons of the predicted RT peptide indicate a close relationship with the RT protein from the gypsy family of LTR-retrotransposons. The possible role of these retrotransposons in generating genetic variability in the homothallic C. perniciosa is discussed.

Genome projects, both genomic DNA and ESTs (cDNA), generate a large amount of information, demanding time and a well-structured bioinformatics laboratory to manage these data. These genome projects use information available in heterogeneous formats from different sources. The amount and heterogeneity of this information, as well as the absence of a world consensus pattern, make the integration of these data a difficult task. At the same time, sub-tasks, such as microarray analyses of these projects, are very complex. This creates a demand for the development of creative solutions for ongoing annotation, thematic projects, microarray experiments, etc. This paper presents Gene Projects, a system developed to integrate all kinds of solutions.

Hydromedusa maximiliani is a vulnerable neotropical freshwater turtle endemic to mountainous regions of the Atlantic rainforest in southeastern Brazil. Random amplified polymorphic DNA (RAPD) was used to estimate the gene flow and dispersal for individuals inhabiting rivers and streams within a drainage. Nine primers generated 27 scoreable bands, of which 9 (33%) were polymorphic and produced 12 RAPD phenotypes. The gene flow estimates (Nm) among turtles inhabiting different rivers and streams were variable, ranging from 0.09 to 3.00 (mean: 0.60). For some loci, the rates of gene flow could offset population differentiation (Nm > 1), whereas for others random genetic drift could result in population divergence (Nm < 1). Since the genetic variation of this turtle seems to be structured according to the natural hierarchical system of rivers and streams within drainages, management programs involving translocations between different regions across the geographical range of H. maximiliani should be viewed with caution.

Background The use of lignocellulosic biomass rather than fossil fuel is an environmental sustainable alternative for bioethanol production. However, fermentation of lignocellulosic hydrolysates by Saccharomyces cerevisiae is not viable since this yeast cannot ferment xylose naturally. Current, several studies are being developed to introduce a pathway that allows pentose fermentation by S. cerevisiae [1]. The bacterium Propionibacterium acidipropionici, employed in many industrial processes, is able to efficiently ferment xylose using the enzyme xylose isomerase. Xylose isomerase, codified by the XI gene, converts xylose to xylulose [2]. This study aims to develop a yeast capable of fermenting xylose through the expression of the P. acidipropioniciXI gene in S. cerevisiae. Furthermore, the effect of the over expression of a gene that encodes a xylulokinase (XKS1) and the deletion of the gene that codifies an aldose reductase (AR) together with the expression of the XI gene were evaluated. These enzymes are crucial for xylose fermentation since the former converts xylulose to xylulose-5-P by the pentose phosphate pathway (PPP) and the last converts xylose into xylitol, which can alter the xylose isomerase activity [3].

Background Eucalyptus is one of the most important sources of industrial cellulose. Three species of this botanical group are intensively used in breeding programs: E. globulus, E. grandis and E. urophylla. E. globulus is adapted to subtropical/temperate areas and is considered a source of high-quality cellulose; E. grandis grows rapidly and is adapted to tropical/subtropical climates; and E. urophylla, though less productive, is considered a source of genes related to robustness. Wood, or secondary xylem, results from cambium vascular differentiation and is mostly composed of cellulose, lignin and hemicelluloses. In this study, the xylem transcriptomes of the three Eucalyptus species were investigated in order to provide insights on the particularities presented by each of these species. Results Data analysis showed that (1) most Eucalyptus genes are expressed in xylem; (2) most genes expressed in species-specific way constitutes genes with unknown functions and are interesting targets for future studies; (3) relevant differences were observed in the phenylpropanoid pathway: E. grandis xylem presents higher expression of genes involved in lignin formation whereas E. urophylla seems to deviates the pathway towards flavonoid formation; (4) stress-related genes are considerably more expressed in E. urophylla, suggesting that these genes may contribute to its robustness. Conclusions The comparison of these three transcriptomes indicates the molecular signatures underlying some of their distinct wood characteristics. This information may contribute to the understanding of xylogenesis, thus increasing the potential of genetic engineering approaches aiming at the improvement of Eucalyptus forest plantations productivity.

Background Eucalyptus forests are a competitive and efficient alternative to convert carbon from the atmosphere in cellulose, an important source for paper manufacture and bioenergy production. To obtain transgenic Eucalyptus with important traits improved it is necessary to make modifications in genes that affect the final phenotype. One interesting gene that follows this requisite was recently found: this is the AtSHN2 gene (Arabidopsis thaliana SHINE 2). AtSHN2 codifies to a Transcription Factor known as “Arabidopsis SHINE/WAX INDUCER”. Instead of inducing drought tolerance in transgenic rice (Oryza sativa), AtSHN2 overexpression causes: i) 34% increase in the cellulose content; ii) 45% reduction in lignin content and iii) increase in wood digestibly (elevated S:G ratio) with no compromise in plant strength and performance [1]. The discovery of AtSHN2 function in plant cell wall formation, led Ambavaram and collaborators [1] to perform other studies and ultimately to propose the following model: AtSHN2 regulates positively MYB transcription factors (TF) related to cellulose synthesis and it downregulates MYBTF’s related to lignin formation. At the same time, SHINE can repress NAC TFthat controls MYB expression[1]. As a consequence of the interesting phenotype achieved through AtSHN2 overexpression in rice, this work focused on the identification and analyses of AtSHN orthologues in Eucalyptus. Bioinformatics tools were used to search for AtSHN similar genes in Eucalyptus. Moreover, the expression profile of the corresponding genes in Eucalyptus was evaluated to prove their role as AtSHN. To carry it on, the expression experiments were done with flower, leaf and xylem. If the Eucalyptus putativeSHINE’s has the same function of the AtSHN’s,, gene expression in flower tissues will be the highest [2]. This is because it is known that AtSHN’s genes are preferentially expressed in abscission and dehiscence zones, a phenomenon that usually occurs in lots of flower tissues.

Background For three decades the Mutator system was thought to be exclusive of plants, until the first homolog representatives were characterized in fungi and in early-diverging amoebas earlier in this decade. Results Here, we describe and characterize four families of Mutator-like elements in a new eukaryotic group, the Parabasalids. These T richomonas v aginalis Mu tator- l ike e lements, or TvMULEs, are active in T. vaginalis and patchily distributed among 12 trichomonad species and isolates. Despite their relatively distinctive amino acid composition, the inclusion of the repeats TvMULE1, TvMULE2, TvMULE3 and TvMULE4 into the Mutator superfamily is justified by sequence, structural and phylogenetic analyses. In addition, we identified three new TvMULE-related sequences in the genome sequence of Candida albicans. While TvMULE1 is a member of the MuDR clade, predominantly from plants, the other three TvMULEs, together with the C. albicans elements, represent a new and quite distinct Mutator lineage, which we named TvCaMULEs. The finding of TvMULE1 sequence inserted into other putative repeat suggests the occurrence a novel TE family not yet described. Conclusion These findings expand the taxonomic distribution and the range of functional motif of MULEs among eukaryotes. The characterization of the dynamics of TvMULEs and other transposons in this organism is of particular interest because it is atypical for an asexual species to have such an extreme level of TE activity; this genetic landscape makes an interesting case study for causes and consequences of such activity. Finally, the extreme repetitiveness of the T. vaginalis genome and the remarkable degree of sequence identity within its repeat families highlights this species as an ideal system to characterize new transposable elements.

Background Nitrogen (N) is a main nutrient required for tree growth and biomass accumulation. In this study, we analyzed the effects of contrasting nitrogen fertilization treatments on the phenotypes of fast growing Eucalyptus hybrids (E. urophylla x E. grandis) with a special focus on xylem secondary cell walls and global gene expression patterns. Results Histological observations of the xylem secondary cell walls further confirmed by chemical analyses showed that lignin was reduced by luxuriant fertilization, whereas a consistent lignin deposition was observed in trees grown in N-limiting conditions. Also, the syringyl/guaiacyl (S/G) ratio was significantly lower in luxuriant nitrogen samples. Deep sequencing RNAseq analyses allowed us to identify a high number of differentially expressed genes (1,469) between contrasting N treatments. This number is dramatically higher than those obtained in similar studies performed in poplar but using microarrays. Remarkably, all the genes involved the general phenylpropanoid metabolism and lignin pathway were found to be down-regulated in response to high N availability. These findings further confirmed by RT-qPCR are in agreement with the reduced amount of lignin in xylem secondary cell walls of these plants. Conclusions This work enabled us to identify, at the whole genome level, xylem genes differentially regulated by N availability, some of which are involved in the environmental control of xylogenesis. It further illustrates that N fertilization can be used to alter the quantity and quality of lignocellulosic biomass in Eucalyptus, offering exciting prospects for the pulp and paper industry and for the use of short coppices plantations to produce second generation biofuels. Electronic supplementary material The online version of this article (doi:10.1186/s12870-014-0256-9) contains supplementary material, which is available to authorized users.