Finding optimal microorganisms to increase crop productivity and sustainability under drought – a structured reflection

Considering the more frequent and longer drought events due to climate change, improving plant drought tolerance became a priority. The search for plant growth promoting rhizobacteria (PGPR) able to improve plant drought tolerance has been long addressed, but with inconsistent results. Here, we summarize the PGPR mechanisms that improve plant drought tolerance, identify the pitfalls in current PGPR isolation and selection routines, and discuss the key points to define new strategies to get optimal PGPR for plant drought tolerance. Drought and host genotype impact rhizo-communities, and host-mediated selection strategies may be used to obtain a drought-adapted rhizomicrobiome that can be a source for PGPR isolation. Alternatively, an integrated omics-level analysis can improve our knowledge on the mechanisms of rhizomicrobiome construction, and a targeted approach can be designed, which will be focused on key PGP traits. New strategies to build PGPR consortia for improvement of plant drought tolerance are also suggested.info:eu-repo/semantics/publishedVersio

Novel benzopsoralen analogues : synthesis, biological activity and molecular docking studies

New benzopsoralen analogues were synthesized and their inhibitory effect on the growth of tumourtumour cell lines (MDA MB231 and TCC-SUP) was evaluated. The in vitro antitumour activity of the new benzopsoralen analogues was discussed in terms of structure–activity relationship. Molecular docking studies with human-CYP2A6 enzymes were also carried out with the synthesized compounds to evaluate the potential of these molecules to interact with the haem group of the enzymes. The results demonstrated that the compounds that are able to interact with the iron ion of the haem cofactor and at the same time with active site Asn297 are those that have better anti-proliferative activity.To the Foundation for the Science and Technology (FCT, Portugal) for financial support to the NMR Portuguese network (PTNMR, Bruker Avance III 400-Univ. Minho). FCT and FEDER (European Fund for Regional Development)-COMPETE-QREN-EU for financial support to the Chemistry Research Centre, CQ/UM [PEst-C/QUI/UI0686/2011 (FCOMP-01-0124-FEDER-022716)], to REQUIMTE (PEst-C/EQB/LA0006/2011), to the Centre of Biological Engineering (PEst-OE/EQB/LA0023/2013) and the PhD grant to C.S.F. (SFRH/BD/48636/2008). The authors also acknowledge the Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP, Porto, Portugal) for kindly providing the breast cancer cell lines used in this work

Perfect category-graded algebras

In a perfect category every object has a minimal projective resolution. We give a criterion for the category of modules over a categorygraded algebra to be perfect.Comment: A sufficient condition is replaced by a criterion. Several references added. 17 page

Synthesis of novel psoralen analogues and their in vitro antitumor activity

New tetracyclic benzofurocoumarin (benzopsoralen) analogues were synthesized and their inhibitory effect on the growth of tumor cell lines was evaluated. The human tumor cell lines used were MDA MB231 (breast adenocarcinoma), HeLa (cervix adenocarcinoma) and TCC-SUP (bladder transitional cell carcinoma). The in vitro antitumor activity of the new benzopsoralens was discussed in terms of structure–activity relationship. Molecular docking studies with human-CYP2A6 enzymes were also carried out with the synthesized compounds in order to evaluate the potential of these compounds to interact with the heme group of the enzymes. The results have demonstrated that the linear compounds have the most pronounced activity against tumor cell lines and this might be related to the better accessibility that these compounds have to the active site in relation to the angular ones that have shown in the majority of the cases multiple binding poses in the active site of CYP2A6.To the Foundation for the Science and Technology (FCT, Portugal) for financial support to the NMR portuguese network (PTNMR, Bruker Avance III 400-Univ. Minho). FCT and FEDER (European Fund for Regional Development)-COMPETE-QREN-EU for financial support to the Research Centre, CQ/UM [PEst-C/QUI/UI0686/2011 (FCOMP-01-0124-FEDER-022716)], (Pest-C/EQB/LA0006/2011) and the PhD grant to C.S.F. (SFRH/BD/48636/2008). The authors also acknowledge the Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP, Porto, Portugal) for kindly providing the breast cancer cell line used in this work

Synthesis of novel psoralen analogues derived from 7-hydroxy-4-methylcoumarin

Fundação para a Ciência e a Tecnologia (FCT) FEDER (European Fund for Regional Development)-COMPETE-QREN-EU FCOMP-01-0124-FEDER-022716FEDER (European Fund for Regional Development)-COMPETE-QREN-EU FCOMP-01-0124-FEDER-02271

Achromobacter xylosoxidans and Enteromorpha intestinalis Extract Improve Tomato Growth under Salt Stress

The effect of seed coating salt-stressed tomato with the bacterium Achromobacter xylosoxidans BOA4 and/or irrigation with an extract of the marine algae Enteromorpha intestinalis (EI) is herein evaluated. The plant shoots and roots were harvested separately on day 50, following extensive saline stress. The addition of BOA4 and/or EI extract resulted in an average increase of 33% in plant shoot DW, but an averaged decrease of 44% in the root to shoot biomass ratio. Anthocyanin content increased by over 34% and 44% with EI and BOA4 plus EI treatments, respectively. Since enhanced protein tyrosine nitration (PTN) is a known plant response to salt stress, the PTN level was inspected through 3-nitrotyrosine content determination. This was drastically increased by salt stress; however, BOA4, EI or both caused an averaged PTN decrease of 30% in stressed roots or shoots. This PTN response could be associated with tomato phenotypic characteristics and is postulated to be inversely correlated to cytokinin contents in stressed plants, namely cis-zeatin-type-cis-zeatin (cZ) plus cis-zeatin riboside (cZR), and isopentenyladenine (iP). The latter showed a drastic average increase by 3.6-fold following BOA4 and/or EI treatments of salinized tomato. This increment could be related to cytokinin biosynthesis induced by the applied bio-stimulants; IP and derivatives are the main cytokinins in seaweeds, and Achromobacter xylosoxidans BOA4 was shown to produce up to 17.5 pmol mL−1 of isopentenyladenine. This work is the first report on the influence of bio-stimulants, used to improve salt stress tolerance, on plant PTN levels; BOA4 and/or EI treatments decreased PTN, while increasing cis-zeatin-type and iP cytokinins in tomato, the latter showed an enhanced tolerance to salt stress.info:eu-repo/semantics/publishedVersio

Post-fire Regeneration Traits of Understorey Shrub Species Modulate Successional Responses to High Severity Fire in Mediterranean Pine Forests

Recurrent fires can impede the spontaneous recruitment capacity of pine forests. Empirical studies have suggested that this can lead to a prolonged replacement of pine forest by shrubland, especially if shrub species are pyrophytic. Model-based studies, however, have suggested that post-fire succession of pine forest under current climatic conditions will eventually tend towards the dominance of oaks under high fire severity and recurrence. These previous modelling studies did not address the role of the various post-fire regeneration traits of the understory shrub species. Considering the dichotomy of obligate seeder vs. resprouter species, either obligate or facultative resprouter, we hypothesized that when the shrubs present are post-fire seeders, the oaks steadily occupy the forest, whereas resprouter shrub species might compete with oaks and delay or arrest post-fire succession. To test this hypothesis, we developed a dynamic, cellular automaton model for simulating post-fire successional transitions in pine forests, including shrubs, pines and oaks, and stochastic fires of regular frequency. Our results showed a strong tendency towards oak dominance as final model state and a very reduced role of fire recurrence in this final state, with low yearly acorn input delaying oak dominance. Most relevantly, and in line with our hypothesis, the trend towards oak dominance depended markedly on the two types of shrub species, being delayed by resprouter species, which extended the shrub-dominated succession stage for several centuries. Our simulation results supported the view that the type of understorey species should be a key consideration in post-fire restoration strategies aiming to enhance fire resilience.This research has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under the grant agreement no. 283068 (CASCADE project). Thanks are due to FCT/MCTES for the financial support to CESAM (UIDP/50017/2020+UIDB/50017/2020), through national funds and the post-doctoral research contract of Jacob Keizer (FCT-IF/01465/2015), and to the Spanish Ministry of Science and Innovation for financial support (CGL2017-89804-R) of the work of Susana Bautista. The work of Paula Maia was partially supported by the project SuSPiRe (PTDC/ASP-SIL/30983/2017) funded by FCT, through COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI)

Reactivation of latent HIV-1 in vitro using an ethanolic extract from Euphorbia umbellata (Euphorbiaceae) latex

Euphorbia umbellata (E. umbellata) belongs to Euphorbiaceae family, popularly known as Janauba, and its latex contains a combination of phorbol esters with biological activities described to different cellular protein kinase C (PKC) isoforms. Here, we identified deoxi-phorbol esters present in E. umbellata latex alcoholic extract that are able to increase HIV transcription and reactivate virus from latency models. This activity is probably mediated by NF-kB activation followed by nuclear translocation and binding to the HIV LTR promoter. In addition, E. umbellata latex extract induced the production of pro inflammatory cytokines in vitro in human PBMC cultures. This latex extract also activates latent virus in human PBMCs isolated from HIV positive patients as well as latent SIV in non-human primate primary CD4+ T lymphocytes. Together, these results indicate that the phorbol esters present in E. umbellata latex are promising candidate compounds for future clinical trials for shock and kill therapies to promote HIV cure and eradication.Research and experimental expenses were funded by the grant E26/2015064289 from FAPERJinfo:eu-repo/semantics/publishedVersio

Social differences in avoidable mortality between small areas of 15 European cities : an ecological study

Peer reviewe

The cause of urinary symptoms among Human T Lymphotropic Virus Type I (HLTV-I) infected patients: a cross sectional study

BACKGROUND: HTLV-I infected patients often complain of urinary symptomatology. Epidemiological studies have suggested that these individuals have a higher prevalence and incidence of urinary tract infection (UTI) than seronegative controls. However, the diagnosis of UTI in these studies relied only on patient information and did not require confirmation by urine culture. The purpose of this study was to investigate the role of urinary tract infection (UTI) as the cause of urinary symptoms in HTLV-I infected patients. METHODS: In this cross sectional study we interviewed, and cultured urine from, 157 HTLV-I seropositive individuals followed regularly at a specialized clinic. All patients were evaluated by a neurologist and classified according to the Expanded Disability Status Scale (EDSS). Urodynamic studies were performed at the discretion of the treating physician. RESULTS: Sixty-four patients complained of at least one active urinary symptom but UTI was confirmed by a positive urine culture in only 12 of these patients (19%); the majority of symptomatic patients (81%) had negative urine cultures. To investigate the mechanism behind the urinary complaints in symptomatic individuals with negative urine cultures, we reviewed the results of urodynamic studies performed in 21 of these patients. Most of them (90.5%) had abnormal findings. The predominant abnormalities were detrusor sphincter hyperreflexia and dyssynergia, findings consistent with HTLV-I-induced neurogenic bladder. On a multivariate logistic regression, an abnormal EDSS score was the strongest predictor of urinary symptomatology (OR 9.87, 95% CI 3.465 to 28.116, P < 0.0001). CONCLUSION: Urinary symptomatology suggestive of UTI is highly prevalent among HTLV-I seropositive individuals but true UTI is responsible for the minority of cases. We posit that the main cause of urinary symptoms in this population is neurogenic bladder. Our data imply that HLTV-I infected patients with urinary symptomatology should not be empirically treated for UTI but rather undergo urine culture; if a UTI is excluded, further investigation with urodynamic studies should be considered