Background Corynebacterium pseudotuberculosis, a Gram-positive, facultative intracellular pathogen, is the etiologic agent of the disease known as caseous lymphadenitis (CL). CL mainly affects small ruminants, such as goats and sheep; it also causes infections in humans, though rarely. This species is distributed worldwide, but it has the most serious economic impact in Oceania, Africa and South America. Although C. pseudotuberculosis causes major health and productivity problems for livestock, little is known about the molecular basis of its pathogenicity.Methodology and FindingsWe characterized two C. pseudotuberculosis genomes (Cp1002, isolated from goats; and CpC231, isolated from sheep). Analysis of the predicted genomes showed high similarity in genomic architecture, gene content and genetic order. When C. pseudotuberculosis was compared with other Corynebacterium species, it became evident that this pathogenic species has lost numerous genes, resulting in one of the smallest genomes in the genus. Other differences that could be part of the adaptation to pathogenicity include a lower GC content, of about 52%, and a reduced gene repertoire. The C. pseudotuberculosis genome also includes seven putative pathogenicity islands, which contain several classical virulence factors, including genes for fimbrial subunits, adhesion factors, iron uptake and secreted toxins. Additionally, all of the virulence factors in the islands have characteristics that indicate horizontal transfer.ConclusionsThese particular genome characteristics of C. pseudotuberculosis, as well as its acquired virulence factors in pathogenicity islands, provide evidence of its lifestyle and of the pathogenicity pathways used by this pathogen in the infection process. All genomes cited in this study are available in the NCBI Genbank database (http://www.ncbi.nlm.nih.gov/genbank/) under accession numbers CP001809 and CP001829.

Phosphorus (P) stress responsive genes have been identified and characterized, including the highaffinity phosphate transporter AtPHT1;4 from Arabidopsis thaliana. This gene encodes a membrane protein that is primarily expressed in roots under phosphorus deficiency. A 2.3-kb promoter region from AtPHT1;4 has been fused with the β-glucuronidase (GUS) encoding gene and introduced into maize via biolistic bombardment to evaluate its spatiotemporal activity in a heterologous system. AtPHT1;4::GUS expression is detected preferentially in transgenic maize roots under P deficiency. Further analysis of transgenic plants has also revealed that GUS activity is higher in roots than in leaves by about sixfold. These results demonstrate the ability of AtPHT1;4 promoter to direct expression of the reporter gene in a monocot root system under P stress. This property of AtPHT1;4 promoter makes it useful to engineer maize plants to modify the soil's rhizosphere and increase efficiency of P acquisition under P stress conditions.

Although several ant species are important targets for the development of molecular control strategies, only a few studies focus on identifying and validating reference genes for quantitative reverse transcription polymerase chain reaction (RT-qPCR) data normalization. We provide here an extensive study to identify and validate suitable reference genes for gene expression analysis in the ant Atta sexdens, a threatening agricultural pest in South America. The optimal number of reference genes varies according to each sample and the result generated by RefFinder differed about which is the most suitable reference gene. Results suggest that the RPS16, NADH and SDHB genes were the best reference genes in the sample pool according to stability values. The SNF7 gene expression pattern was stable in all evaluated sample set. In contrast, when using less stable reference genes for normalization a large variability in SNF7 gene expression was recorded. There is no universal reference gene suitable for all conditions under analysis, since these genes can also participate in different cellular functions, thus requiring a systematic validation of possible reference genes for each specific condition. The choice of reference genes on SNF7 gene normalization confirmed that unstable reference genes might drastically change the expression profile analysis of target candidate genes.

Oil palm cultivation has acquired economic importance due to rising demand for vegetable oils used in food, pharmaceutical, cosmetic and most recently, in biofuel industries. However, the commercial production increase of oil palm is limited by plantlet production, as it primarily uses seeds that require a long germination period and have low germination rates. In this study we evaluated the effect of embryo age (time after pollination), culture media and presence of carbohydrates on in vitro germination of zygotic embryos of oil palm (Elaeis guineensis Jacq.) Manicoré hybrid. Embryos at 80, 90, 100 and 110 days post-anthesis were inoculated in MS medium or modified Y3 medium, with or without 3% sucrose. Media were renewed after 30 days of inoculation, and plantlets were kept for 45 days until collection for histological analyses. The embryos did not germinate in medium without sucrose. Embryos of 100 days post-anthesis in MS medium showed the best result for germination rate (88%), which did not differ statistically from Y3 medium. As for the parameters, 90-day embryos showed better results for number and length of roots in Y3 medium. It was concluded that 90-day embryos cultivated in Y3 medium generate plantlets in better conditions to be transferred to acclimatization.

The plant hormone ethylene is involved in the regulation of a multitude of plant processes, ranging from seed germination to organ senescence. Ethylene induces fruit ripening in climacteric fruits, such as coffee, being directly involved in fruit ripening time and synchronization. Coffee early cultivars usually show a more uniform ripening process although little is known about the genetic factors that promote the earliness of ripening. Thus, this work aimed to characterize the putative members of the coffee (Coffea arabica) ethylene biosynthesis and signaling pathways, as well as to analyze the expression patterns of these members during fruit ripening of early (Catucaí 785-15) and late (Acauã) coffee cultivars. Reverse Transcription-qPCR analysis of the four biosynthesis genes (CaACS1-like; CaACO1-like; CaACO4-like e CaACO5-like) analyzed in this study showed that CaACO1-like and CaACO4-like displayed an expression pattern typically observed in climacteric fruits, being up-regulated during ripening. CaACS1-like gene expression was also up-regulated during fruit ripening of both cultivars, although in a much lesser extent when compared to the changes in CaACO1-like and CaACO4-like gene expression. CaACO5-like was only induced in raisin fruit and may be related to senescence processes. On the other hand, members of the ethylene signaling pathway (CaETR1-like, CaETR4-like, CaCTR2-like, CaEIN2-like, CaEIN3-like, CaERF1) showed slightly higher expression levels during the initial stages of development (green and yellow-green fruits), except for the ethylene receptors CaETR1-like and CaETR4-like, which were constitutively expressed and induced in cherry fruits, respectively. The higher ethylene production levels in Catucaí 785-15 fruits, indicated by the expression analysis of CaACO1-like and CaACO4-like, suggest that it promotes an enhanced CaETR4-like degradation, leading to an increase in ethylene sensitivity and consequently to an earliness in the ripening process of this cultivar. Ethylene production in Acauã fruits may not be sufficient to inactivate the CaETR4-like levels and thus ripening changes occur in a slower pace. Thus, the expression analysis of the ethylene biosynthesis and signaling genes suggests that ethylene is directly involved in the determination of the ripening time of coffee fruits, and CaACO1-like, CaACO4-like and CaETR4-like may display essential roles during coffee fruit ripening.

6RESUMO -Fruits and almond from the dendezeiro, oil palmbelonging to the Elaeis genus,are widely used for the production of cookingoils or for the pharmaceutical and cosmetic industries.In the last decade, this oil palm also emerged as a promising source for commercialbiofuel production. This study evaluated the effect of different culture media, MS (MURASHIGUE AND SKOOG) and Y3 (EEUWENS)and carbohydrates duringin vitro germination of zygotic embryos, the effect of growth regulators GA 3 , NAA and BA Ponin vitro seedling development, and the survival rate of acclimatized seedlingsof Manicoré hybrid (Elaeis oleifera x E. guineensis). Zygotic embryos were inoculated on MS and modified Y3 media, supplemented with different sucrose concentrations (30, 45, and 60 gL -1 ) or sorbitol (36 gL -1 ), and the germination rate was evaluated after 30 days. Subsequently, seedlings were transferred to modified Y3 culture medium supplemented with differentGA 3 concentrations (3.5 and 7 mgL -1 ) or without it, combined or not with 1 mgL -1 of NAA, 5 mgL -1 of BAP.The highest germinationpercentage of germinated embryos (92%) was observed in MS medium supplemented with 36 gL -1 sorbitol. Culture media supplemented with growth regulatorsGA 3 , NAA and BAP promoted greater shoot lengththan control media. Rooted seedlings showed high survival percentage (85%) during acclimatization.Palavras-chave: Germination; Carbohydrates; Growth regulators. DESENVOLVIMENTO IN VITRO E ACLIMATIZAÇÃO DE PLÂNTULAS DE DENDEZEIRO

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Bacillus thuringiensis (Bt) endotoxins (Cyt and Cry) have been extensively explored for biological control of fall armyworm, Spodoptera frugiperda, an important pest in major corn-producing countries of America. Five hundred Bt isolates with different toxicities against S. frugiperda were characterized by PCR for the presence of cyt genes (cyt1, cyt2, cyt1Aa, cyt1Ab, cyt2B and cyt2Ba), and the effect of insecticidal proteins Cry1Ba, Cry1Ca, Cry1Da and Cyt on S. frugiperda larvae were evaluated. Six isolates showed the presence of cyt genes, three isolates harbored two gene families (cyt1 and cyt2), and three isolates harbored only one of the cyt gene families (cyt1 and cyt2). It was not possible to correlate the presence/absence of cyt genes with toxicity against S. frugiperda. In this study, cyt genes were present in toxic and nontoxic isolates to this insect pest. Bioassays against S. frugiperda larvae showed that only Cry1Ca protein had toxicity, with 77.08% of mortality. Synergism among Cry and Cry proteins used in this study against S. frugiperda was not observed.