Coeficiente de extinção de radiação fotossinteticamente ativa em canola sob distintos espaçamentos.

A radiação fotossinteticamente ativa (RFA) é extremamente importante no crescimento e desenvolvimento vegetal. A variação do espaçamento entre fileiras de plantas determina uma alteração na interceptação da RFA. A distribuição mais homogênea das plantas dentro do dossel contribui para uma maior interceptação da radiação com aumento no coeficiente de extinção de RFA no dossel

An anti-infective synthetic peptide with dual antimicrobial and immunomodulatory activities

Antibiotic-resistant infections are predicted to kill 10 million people per year by 2050, costing the global economy $100 trillion. Therefore, there is an urgent need to develop alternative technologies. We have engineered a synthetic peptide called clavanin-MO, derived from a marine tunicate antimicrobial peptide, which exhibits potent antimicrobial and immunomodulatory properties both in vitro and in vivo. The peptide effectively killed a panel of representative bacterial strains, including multidrug-resistant hospital isolates. Antimicrobial activity of the peptide was demonstrated in animal models, reducing bacterial counts by six orders of magnitude, and contributing to infection clearance. In addition, clavanin-MO was capable of modulating innate immunity by stimulating leukocyte recruitment to the site of infection, and production of immune mediators GM-CSF, IFN-γ and MCP-1, while suppressing an excessive and potentially harmful inflammatory response by increasing synthesis of anti-inflammatory cytokines such as IL-10 and repressing the levels of pro-inflammatory cytokines IL-12 and TNF-α. Finally, treatment with the peptide protected mice against otherwise lethal infections caused by both Gram-negative and -positive drug-resistant strains. The peptide presented here directly kills bacteria and further helps resolve infections through its immune modulatory properties. Peptide anti-infective therapeutics with combined antimicrobial and immunomodulatory properties represent a new approach to treat antibiotic-resistant infections

Selective antibacterial activity of the cationic peptide PaDBS1R6 against Gram-negative bacteria

© 2019 Elsevier B.V. All rights reserved.Infections caused by Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa foremost among them, constitute a major worldwide health problem. Bioinformatics methodologies are being used to rationally design new antimicrobial peptides, a potential alternative for treating these infections. One of the algorithms used to develop antimicrobial peptides is the Joker, which was used to design the peptide PaDBS1R6. This study evaluates the antibacterial activities of PaDBS1R6 in vitro and in vivo, characterizes the peptide interaction to target membranes, and investigates the PaDBS1R6 structure in contact with mimetic vesicles. Moreover, we demonstrate that PaDBS1R6 exhibits selective antimicrobial activity against Gram-negative bacteria. In the presence of negatively charged and zwitterionic lipids the structural arrangement of PaDBS1R6 transits from random coil to α-helix, as characterized by circular dichroism. The tertiary structure of PaDBS1R6 was determined by NMR in zwitterionic dodecylphosphocholine (DPC) micelles. In conclusion, PaDBS1R6 is a candidate for the treatment of nosocomial infections caused by Gram-negative bacteria, as template for producing other antimicrobial agents.This work was supported by Fundação para a Ciência e a Tecnologia – Ministério da Ciência, Tecnologia e Ensino Superior (FCT-MCTES, Portugal) project PTDC/BBB-BQB/3494/2014, Marie Skłodowska-Curie Research and Innovation Staff Exchange (MSCA-RISE, European Union) project INPACT (call H2020-MSCA-RISE-2014, grant agreement 644167), Ramon Areces Foundation (to CFN), DTRA (HDTRA1-15-1-0050 to TKL), Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP #2016/24413-0 to MDTT), Fundação de Amparo à Pesquisa do Estado de Goiás (FAPEG # 201710267000062 to ESFA) and Fundação de Apoio à Pesquisa do Distrito Federal (FAPDF). MRF acknowledges FCT-MCTES fellowship SFRH/BD/100517/2014. ONS holds a postdoctoral scholarship from National Council of Technological and Scientific Development (CNPq) and Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul (FUNDECT) – Brazil [300583/2016-8]. MHC acknowledges fellowship 141518/2015-4 (CNPq) and 88881.134423/2016-01 (CAPES).info:eu-repo/semantics/publishedVersio