Characterization of the Role of Pseudomonas syringae Type III Effector HopAF1 in Virulence

Many plant pathogens, including Pseudomonas syringae, encode the type III secretion system for translocating effector proteins into the host during infection. Strains of P. syringae which are not capable of delivering the type III effectors are nonpathogenic. Therefore, the functions of type III effectors are essential for disease. Although several type III effectors have been demonstrated to block components of the plant defense response, the functions of most type III effectors are unknown. Our lab is interested in the type III effector HopAF1, a type III effector that is present in eleven of the nineteen sequenced strains of P. syringae and other plant pathogens. Although the presence of HopAF1 in multiple strains of P. syringae suggests that it plays an important role in virulence, no function has yet been associated with HopAF1. We generated a tertiary structural prediction for HopAF1, which suggests that HopAF1 is structurally related to bacterial deamidases. Deamidation, the irreversible substitution of an amide group with a carboxylate group, is the mechanism by which several bacterial virulence factors manipulate the activity of a specific substrate. To identify a potential target of HopAF1 activity, we employed a yeast two-hybrid screen and identified Arabidopsis methylthioadenosine nucleosidase (MTN1) as a putative target of HopAF1. This interaction, which we extended to include Arabidopsis MTN2, was confirmed in planta using coimmunoprecipitations and bimolecular fluorescence complementation assays. MTNs are enzymes in the Yang cycle, a cycle essential for high levels of ethylene biosynthesis. Ethylene is a key plant hormone for plant developmental processes, such as senescence and flowering. Ethylene is also induced during PTI. Therefore, we hypothesized that HopAF1 inhibits PTI by manipulating MTNs and levels of ethylene in plants. To this end, we used gas chromatography to measure ethylene biosynthesis in plants treated with bacterially-delivered HopAF1. We determined that HopAF1 inhibits ethylene biosynthesis in a manner dependent on putative catalytic residues. Additionally, Yang cycle mutants mtn1 mtn2 and mtk are more susceptible to weak pathogens. This data is consistent with the idea that HopAF1 targets a novel component of the plant immune system, the Yang cycle.Doctor of Philosoph

New range limit of the Anopetia gounellei (Aves: Trochilidae): state of art and a review on the updated area

New technologies and the rapid amount of data help to improve and update the distribution of the species. Anopetia gounellei (Broad-tipped Hermit, Trochilidae) is a poorly known hummingbird and has been recorded outside its formal range since 2009. Here we reviewed the records of the Broad-tipped Hermit, proposing new range limits and discussing the species ecoregional endemism. The species was recorded in a variety of vegetation, including caatinga and humid forest. Our updated range-limit suggest an increase of 80% from the previous range, exceeding the Caatinga limits, calling into question the endemism of the species to this biome, but confirming a close relationship with dry ecoregions in Brazil. Basic information about its biology is needed, and further studies about breeding and ecological requirements are recommended

Pseudomonas syringae type III effector HopAF1 suppresses plant immunity by targeting methionine recycling to block ethylene induction

Pseudomonas syringae is a Gram-negative bacterium that uses a type III secretion system to inject type III effector (T3E) proteins into the host to cause disease in plants. Multiple P. syringae T3Es promote virulence by targeting immune system signaling pathways using diverse biochemical mechanisms. We provide evidence for a molecular function of the P. syringae T3E HopAF1. We demonstrate that the C-terminal region of HopAF1 has structural homology to deamidases. We demonstrate that an enzyme important for production of the gaseous signaling hormone ethylene is a target for HopAF1 and show that HopAF1 targets methylthioadenosine nucleosidase proteins MTN1 and MTN2 to dampen ethylene production during bacterial infection

Spring Composers Forum

https://dc.ewu.edu/music_performances/1630/thumbnail.jp

Doctor of Education Newsletter 2020

WSU Doctor of Education Cohort 2020 This newsletter was created by the second Education Doctorate graduate student cohort 2020.https://openriver.winona.edu/educationeddnewsletters/1001/thumbnail.jp

Detection and identification of Xanthomonas pathotypes associated with citrus diseases using comparative genomics and multiplex PCR

Background. In Citrus cultures, three species of Xanthomonas are known to cause distinct diseases. X. citri subsp. citri patothype A, X. fuscans subsp. aurantifolii pathotypes B and C, and X. alfalfae subsp. citrumelonis, are the causative agents of cancrosis A, B, C, and citrus bacterial spots, respectively. Although these species exhibit different levels of virulence and aggressiveness, only limited alternatives are currently available for proper and early detection of these diseases in the fields. The present study aimed to develop a new molecular diagnostic method based on genomic sequences derived from the four species of Xanthomonas. Results. Using comparative genomics approaches, primers were synthesized for the identification of the four causative agents of citrus diseases. These primers were validated for their specificity to their target DNA by both conventional and multiplex PCR. Upon evaluation, their sensitivity was found to be 0.02 ng/mu l in vitro and 1.5 x 10(4) CFU ml(-1) in infected leaves. Additionally, none of the primers were able to generate amplicons in 19 other genomes of Xanthomonas not associated with Citrus and one species of Xylella, the causal agent of citrus variegated chlorosis (CVC). This denotes strong specificity of the primers for the different species of Xanthomonas investigated in this study. Conclusions. We demonstrated that these markers can be used as potential candidates for performing in vivo molecular diagnosis exclusively for citrus-associated Xanthomonas. The bioinformatics pipeline developed in this study to design specific genomic regions is capable of generating specific primers. It is freely available and can be utilized for any other model organism.7CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAIS - FAPEMIG481226/2013-3CFP 51/2013; 3385/2013APQ-02387-1

A high-resolution map of human evolutionary constraint using 29 mammals.

The comparison of related genomes has emerged as a powerful lens for genome interpretation. Here we report the sequencing and comparative analysis of 29 eutherian genomes. We confirm that at least 5.5% of the human genome has undergone purifying selection, and locate constrained elements covering ∼4.2% of the genome. We use evolutionary signatures and comparisons with experimental data sets to suggest candidate functions for ∼60% of constrained bases. These elements reveal a small number of new coding exons, candidate stop codon readthrough events and over 10,000 regions of overlapping synonymous constraint within protein-coding exons. We find 220 candidate RNA structural families, and nearly a million elements overlapping potential promoter, enhancer and insulator regions. We report specific amino acid residues that have undergone positive selection, 280,000 non-coding elements exapted from mobile elements and more than 1,000 primate- and human-accelerated elements. Overlap with disease-associated variants indicates that our findings will be relevant for studies of human biology, health and disease

Relatório de estágio em farmácia comunitária

Relatório de estágio realizado no âmbito do Mestrado Integrado em Ciências Farmacêuticas, apresentado à Faculdade de Farmácia da Universidade de Coimbr