Genomic analysis of eight native plasmids of the phytopathogen Pseudomonas syringae

Comunicación a conferenciaThe pPT23A family of plasmids (PFPs) appears to be indigenous to the plant pathogen Pseudomonas syringae and these plasmids are widely distributed and widely transferred among pathovars of P. syringae and related species. PFPs are sources of accessory genes for their hosts that can include genes important for virulence and epiphytic colonization of plant leaf surfaces. Further understanding of the evolution of the pPT23A plasmid family and the role of these plasmids in P. syringae biology and pathogenesis, requires the determination and analysis of additional complete, closed plasmid genome sequences. Therefore, our main objective was to obtain complete genome sequences from PFPs from three different P. syringae pathovars and perform a comparative genomic analysis. In this work plasmid DNA isolation, purification by CsCl-EtBr gradients, and sequencing using 454 platform, were used to obtain the complete sequence of P. syringae plasmids. Different bioinformatic tools were used to analyze the plasmid synteny, to identify virulence genes (i.e. type 3 effectors) and to unravel the evolutionary history of PFPs. Our sequence analysis revealed that PFPs from P. syringae encode suites of accessory genes that are selected at different levels (universal, interpathovar and intrapathovar). The conservation of type IVSS encoding conjugation functions also contributes to the distribution of these plasmids within P. syringae populations. Thus, this study contributes to unravel the genetic basis of the role of PFPs in different P. syringae lifestyles.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Isolation, characterization and selection of bacterial isolates from a suppressive soil with beneficial traits to plants

Backgrounds This study focused on the characterization and selection of bacterial strains obtained from a suppressive soil displaying antifungal activity against the soilborne phytopathogenic fungi Rosellinia necatrix. Bacterial profile from this suppressive soil were first obtained by 16S rRNA gene sequencing, revealing a significant increase in the bacterial class Gammaproteobacteria, especially in some antagonistic representatives of Pseudomonas spp. Objectives To obtain and characterize a collection of 246 bacterial isolates obtained from this suppressive soil, in order to identify new strains with antifungal activity against fungal phytopathogens. Methods To obtain the bacterial collection, we performed an isolation on a selective medium for Pseudomonas-like microorganisms. Further characterization tests were used in order to analyse the bacterial collection, including identification of the general metabolic profile of glucose, the profiling of antifungals produced, including both the putative production of antifungal compounds and lytic exoenzymes, and the evaluation of traits related with beneficial effects on plants. Conclusions A final selection of representative strains resulted in antifungal isolates belonging to the genus Pseudomonas, but also some representatives of the genera Serratia and Stenotrophomonas. These selected strains were tested for plant protection by an in vivo experiment using avocado and wheat plants challenged by the pathogen R. necatrix, showing all of them an antifungal ability and plant disease protection. Pseudomonas-like strains isolated from suppressive soils constitute an excellent source for novel microbial biocontrol agents against soilborne fungal pathogens. This work was supported by grant AGL2014-52518-C2-1-R. Carmen Vida and Sandra Tienda are supported by a PhD fellowship from the FPI program of the Spanish Government.This work was supported by grant AGL2014-52518-C2-1-R. Carmen Vida and Sandra Tienda are supported by a PhD fellowship from the FPI program of the Spanish Government; Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Identification, characterization and antigenicity of the Plasmodium vivax rhoptry neck protein 1 (PvRON1)

<p>Abstract</p> <p>Background</p> <p><it>Plasmodium vivax </it>malaria remains a major health problem in tropical and sub-tropical regions worldwide. Several rhoptry proteins which are important for interaction with and/or invasion of red blood cells, such as <it>Pf</it>RONs, <it>Pf</it>92, <it>Pf</it>38, <it>Pf</it>12 and <it>Pf</it>34, have been described during the last few years and are being considered as potential anti-malarial vaccine candidates. This study describes the identification and characterization of the <it>P. vivax </it>rhoptry neck protein 1 (<it>Pv</it>RON1) and examine its antigenicity in natural <it>P. vivax </it>infections.</p> <p>Methods</p> <p>The <it>Pv</it>RON1 encoding gene, which is homologous to that encoding the <it>P. falciparum </it>apical sushi protein (ASP) according to the plasmoDB database, was selected as our study target. The <it>pvron1 </it>gene transcription was evaluated by RT-PCR using RNA obtained from the <it>P. vivax </it>VCG-1 strain. Two peptides derived from the deduced <it>P. vivax </it>Sal-I <it>Pv</it>RON1 sequence were synthesized and inoculated in rabbits for obtaining anti-<it>Pv</it>RON1 antibodies which were used to confirm the protein expression in VCG-1 strain schizonts along with its association with detergent-resistant microdomains (DRMs) by Western blot, and its localization by immunofluorescence assays. The antigenicity of the <it>Pv</it>RON1 protein was assessed using human sera from individuals previously exposed to <it>P. vivax </it>malaria by ELISA.</p> <p>Results</p> <p>In the <it>P. vivax </it>VCG-1 strain, RON1 is a 764 amino acid-long protein. <it>In silico </it>analysis has revealed that <it>Pv</it>RON1 shares essential characteristics with different antigens involved in invasion, such as the presence of a secretory signal, a GPI-anchor sequence and a putative sushi domain. The <it>Pv</it>RON1 protein is expressed in parasite's schizont stage, localized in rhoptry necks and it is associated with DRMs. Recombinant protein recognition by human sera indicates that this antigen can trigger an immune response during a natural infection with <it>P. vivax</it>.</p> <p>Conclusions</p> <p>This study shows the identification and characterization of the <it>P. vivax </it>rhoptry neck protein 1 in the VCG-1 strain. Taking into account that <it>Pv</it>RON1 shares several important characteristics with other <it>Plasmodium </it>antigens that play a functional role during RBC invasion and, as shown here, it is antigenic, it could be considered as a good vaccine candidate. Further studies aimed at assessing its immunogenicity and protection-inducing ability in the <it>Aotus </it>monkey model are thus recommended.</p

How Lithium Prices Affect Mergers and Acquisitions in the Lithium Industry.

Is lithium affecting business strategies in the sector? We employ methodologies based on Continuous Wavelet Transform (CWT) and fractional integration and cointegration vector autoregressive models (FCVAR) models to analyze how lithium prices influence mergers and acquisitions (M&A) in the lithium industry over the world. The univariate and the multivariate results obtained using long memory methods support the nonstationary nature of the data, but they seem to be linked in the long-term through a fractional cointegrated relationship. In addition, analysis in the time-frequency domain indicates that both series are highly correlated from 2015 to 2017, finding that the lithium prices explain the M&A behavior after mid-2016 until early 2017.pre-print451 K

Global CO2 emissions and global temperatures: Are they related

This paper deals with the analysis of the relationship between CO2 emissions and temperatures. For this purpose, global CO2 emissions and four measures of global temperatures (land, land and ocean, northern and southern temperatures) are used. We used techniques based on fractional integration and cointegration. The results indicate first that the orders of integration differ in the two variables. Thus, while emissions are I(1) or I(d) with d higher than 1, temperatures display orders of integration strictly smaller than 1 and thus invalidating the hypothesis of cointegration between the two variables. Due to this, another approach is conducted where we suppose that the emissions are weakly exogenous in relation to the temperatures. The results using this approach show a significantly positive relationship between the two variables with a long memory pattern.pre-print303 K

Lithium industry in the behaviour of the mergers and acquisitions in the U.S. oil and gas industry.

Is lithium affecting the U.S. oil and gas industry strategies? Lithium has an increasingly strategic role as clean technologies emerge, affecting the strategies of oil and gas companies in response to energy trends. This paper contributes to this literature, studying the dynamics of lithium industry and mergers and acquisitions in the U.S. oil and gas industry in time-frequency domain. We use methodologies based on Continuous Wavelet Transform (CWT) and Vector AutoRegressive Models (VAR), and the results indicate that both time series are correlated in the long term, where M&A U.S. oil and gas industry dependence on lithium industry has increased, starting in the early 2014 until the end of the sample. Evidence of causality is not found between both time seriespre-print716 K

Lithium industry and the U.S. crude oil prices. A fractional cointegration VAR and a Continuous Wavelet Transform analysis.

This paper analyzes the dynamics of U.S. lithium mining companies, the lithium industry and West Texas Intermediate (WTI) crude oil prices using a Fractional Cointegration Vector AutoRegressive model (FCVAR model) and a Continuous Wavelet Transform (CWT) for its resolution. The results indicate evidence of a negative relationship between FMC Corp with Albermale and SQM stock prices. These results are similar if we analyze the risk based on the beta term structure of each company. Analyzing the fractional differencing parameter for the stock prices and their logs, we observe that they are very persistent, and there are no long-term deviations in the stock prices. The same happens when analyzing the beta term structure. Based on Continuous Wavelet Transform (CWT) methods, our results show that lithium mining companies and the lithium industry are weakly correlated with WTI crude oil prices at higher frequencies (short-run) and persist through the sample period. At lower frequencies (long-term) the time series reached a high level of dependence between late 2012 to mid 2016, concluding that the lithium mining companies and the lithium industry reflect and foreshadow the responsiveness of the WTI crude oil prices during the period mentioned above.pre-print399 K

Automobile components: lithium and cobalt. Evidence of persistence.

This paper deals with the analysis of persistence in the prices of two technologically important metals, namely, lithium and cobalt. Along with them, we also examine four additional series corresponding to World, European, US and Japanese automobiles and component indices. For this purpose, we use long memory techniques based on fractional integration and cointegration. The results indicate that all the series are highly persistent, though we do not find any evidence supporting long run equilibrium relationships between the variables examined.pre-print1100 K

Water prices: persistence, mean reversion and trends.

Time series referring to water prices at different regions all over the world are examined in this paper by using fractionally integrated methods. We look at series corresponding to the following regions: Asia Pacific and Russia, Europe, United States and Latin America as well as global data. The results indicate large degrees of persistence, with the values of the differencing parameter being close to one in all cases and higher under the assumption of uncorrelated errors. If autocorrelation is permitted, a small degree of mean reversion is found in all except the Latin American series. The possibility of structural breaks is also investigated and the results indicate the presence of multiple breaks in the data: three in the case of Latin America and global data; four in Europe and USA and five for the Asian Pacific and Russia. Nevertheless, we do not observe a significant change in the degree of persistence across subsamples and once more mean reversion is found if autocorrelation is permitted.post-print353 K