354 research outputs found
Українська історіографія про партійно-політичну систему Галичини воєнно-революційної доби: загальна характеристика
У статті робиться спроба історіографічного аналізу становища, розвитку, основних завдань і напрямів діяльності партійно-політичної системи в Галичині періоду воєнно-революційної доби. Наголошується на тих проблемах у дослідженні, що залишаються актуальними на сьогодні, і тих, які ще по-справжньому не стали предметом вивчення.In the article is given a shot of historiographical analysis of the situation, development, main tasks and activities of
party and political systems in Galicina during the period of military-revolutionary era. We emphasis on those issues in
the study, which remain relevant today and those that still have not really studied
Molecular aspects of avirulence and pathogenicity of the tomato pathogen Cladosporium fulvum
The molecular understanding of host-pathogen interactions and particularly of specificity forms the basis for studying plant resistance. Understanding why a certain plant species or cultivar is susceptible and why other species or cultivars are resistant is of great importance in order to design new strategies for future crop protection by molecular plant breeding.In this thesis molecular aspects of avirulence and pathogenicity of the tomato pathogen Cladosporium fulvum are described. The interaction C. fulvum - tomato is an excellent model system to study fungus - plant specificity as the communication between pathogen and plant is confined to the apoplast (intercellular space). The ability to obtain intercellular fluid from C. fulvum -infected tomato leaves enabled the isolation and characterization of plant and fungal compounds that might play an important role in pathogenesis and/or the induction of resistance. The purification and characterization of a race-specific peptide elicitor provides the basis for most of the experiments described in this thesis. This peptide was thought to be produced only by races of C. fulvum avirulent on tomato genotypes carrying the resistance gene Cf9 , on which the elicitor induced necrosis.Molecular aspects of avirulence of C. fulvum were first studied by the isolation and characterization of the cDNA encoding the AVR9 race-specific peptide elicitor (Chapter 2). The peptide was shown to be indeed produced by C. fulvum . Races virulent on tomato genotype Cf9 , lack the avr9 gene and do not produce the peptide elicitor thereby evading recognition by tomato genotypes carrying the corresponding resistance gene Cf9. To prove that the avr9 gene is a genuine avirulence gene, races virulent on tomato genotype Cf9 , were transformed with the cloned avr9 gene (Chapter 3). The cultivar-specificity of the transformants was changed from virulent to avirulent on tomato genotype Cf9. The avr9 gene can therefore be considered to be a genuine avirulence gene, the first fungal avirulence gene cloned. Additional proof for the role of the avirulence gene avr9 in specificity was provided by the disruption of avr9 in two races avirulent on tomato genotype Cf9 , by gene replacement, resulting in transformants virulent on tomato genotype Cf9 , (Chapter 4).The avr9 gene encodes a 63 amino acids precursor protein. Removal of a signal peptide results in an extracellular peptide of 40 amino acids. Proteases of C. fulvum are involved in further processing this extracellular peptide by removal of N-terminal amino acids resulting in peptides of 32, 33 and 34 amino acids. Plant factors are responsible for further processing, resulting in the stable peptide elicitor of 28 amino acids (Chapter 5).The avirulence gene avr9 is highly expressed in C. fulvum while growing inside the tomato leaf. The expression of avr9 is induced in C. fulvum grown in vitro under conditions of nitrogen limitation. The high expression of avr9 in C. fulvum growing inside the tomato leaf might be caused by nitrogen limiting conditions in the apoplast (Chapter 6).Pathogenicity of C. fulvum was studied at the molecular level by the isolation of two genes encoding extracellular proteins (ECPs). The ecp1 and ecp2 genes were isolated via the amino acid sequence of ECP1, and polyclonal antibodies raised against ECP2, respectively (Chapter 7). The expression of the ecp genes is highly induced in planta as compared to the in vitro situation. The availability of the cloned ecp genes now enables us to study the role and importance of these genes during pathogenesis by reporter gene analysis and gene disruption.Two models describing the C. fulvum -tomato interaction are presented, dealing with basic compatibility and race-specific incompatibility, respectively (Chapter 8). The improved understanding of pathogen recognition can be exploited in future research to elucidate the role of putative receptors in the resistant plant involved in perception of elicitors and induction of active plant defence
Stop helping pathogens: engineering plant susceptibility genes for durable resistance
Alternatives to protect crops against diseases are desperately needed to secure world food production and make agriculture more sustainable. Genetic resistance to pathogens utilized so far is mostly based on single dominant resistance genes that mediate specific recognition of invaders and that is often rapidly broken by pathogen variants. Perturbation of plant susceptibility (S) genes offers an alternative providing plants with recessive resistance that is proposed to be more durable. S genes enable the establishment of plant disease, and their inactivation provides opportunities for resistance breeding of crops. However, loss of S gene function can have pleiotropic effects. Developments in genome editing technology promise to provide powerful methods to precisely interfere with crop S gene functions and reduce tradeoffs
Managing assessment. Quality planning in assessment procedures of the Dutch Child Protection Board
Stop helping pathogens: engineering plant susceptibility genes for durable resistance
Alternatives to protect crops against diseases are desperately needed to secure world food production and make agriculture more sustainable. Genetic resistance to pathogens utilized so far is mostly based on single dominant resistance genes that mediate specific recognition of invaders and that is often rapidly broken by pathogen variants. Perturbation of plant susceptibility (S) genes offers an alternative providing plants with recessive resistance that is proposed to be more durable. S genes enable the establishment of plant disease, and their inactivation provides opportunities for resistance breeding of crops. However, loss of S gene function can have pleiotropic effects. Developments in genome editing technology promise to provide powerful methods to precisely interfere with crop S gene functions and reduce tradeoffs
Genetical Genomics Reveals Large Scale Genotype-By-Environment Interactions in Arabidopsis thaliana
One of the major goals of quantitative genetics is to unravel the complex interactions between molecular genetic factors and the environment. The effects of these genotype-by-environment interactions also affect and cause variation in gene expression. The regulatory loci responsible for this variation can be found by genetical genomics that involves the mapping of quantitative trait loci (QTLs) for gene expression traits also called expression-QTL (eQTLs). Most genetical genomics experiments published so far, are performed in a single environment and hence do not allow investigation of the role of genotype-by-environment interactions. Furthermore, most studies have been done in a steady state environment leading to acclimated expression patterns. However a response to the environment or change therein can be highly plastic and possibly lead to more and larger differences between genotypes. Here we present a genetical genomics study on 120 Arabidopsis thaliana, Landsberg erecta × Cape Verde Islands, recombinant inbred lines (RILs) in active response to the environment by treating them with 3 h of shade. The results of this experiment are compared to a previous study on seedlings of the same RILs from a steady state environment. The combination of two highly different conditions but exactly the same RILs with a fixed genetic variation showed the large role of genotype-by-environment interactions on gene expression levels. We found environment-dependent hotspots of transcript regulation. The major hotspot was confirmed by the expression profile of a near isogenic line. Our combined analysis leads us to propose CSN5A, a COP9 signalosome component, as a candidate regulator for the gene expression response to shade
BIOM-30. CELL LINE STUDY OF NUCLEOSOME-BASED BIOMARKERS IN THE DIAGNOSIS AND DETECTION OF RELAPSES IN GLIOBLASTOMA
SDPS-13 CELL LINE STUDY OF NUCLEOSOME-BASED BIOMARKERS IN THE DIAGNOSIS AND DETECTION OF RELAPSES IN GLIOBLASTOMA
Genetical Genomics Reveals Large Scale Genotype-By-Environment Interactions in Arabidopsis thaliana
One of the major goals of quantitative genetics is to unravel the complex interactions between molecular genetic factors and the environment. The effects of these genotype-by-environment interactions also affect and cause variation in gene expression. The regulatory loci responsible for this variation can be found by genetical genomics that involves the mapping of quantitative trait loci (QTLs) for gene expression traits also called expression-QTL (eQTLs). Most genetical genomics experiments published so far, are performed in a single environment and hence do not allow investigation of the role of genotype-by-environment interactions. Furthermore, most studies have been done in a steady state environment leading to acclimated expression patterns. However a response to the environment or change therein can be highly plastic and possibly lead to more and larger differences between genotypes. Here we present a genetical genomics study on 120 Arabidopsis thaliana, Landsberg erecta × Cape Verde Islands, recombinant inbred lines (RILs) in active response to the environment by treating them with 3 h of shade. The results of this experiment are compared to a previous study on seedlings of the same RILs from a steady state environment. The combination of two highly different conditions but exactly the same RILs with a fixed genetic variation showed the large role of genotype-by-environment interactions on gene expression levels. We found environment-dependent hotspots of transcript regulation. The major hotspot was confirmed by the expression profile of a near isogenic line. Our combined analysis leads us to propose CSN5A, a COP9 signalosome component, as a candidate regulator for the gene expression response to shade
Bioinformatic Inference of Specific and General Transcription Factor Binding Sites in the Plant Pathogen Phytophthora infestans
Plant infection by oomycete pathogens is a complex process. It requires precise expression of a plethora of genes in the pathogen that contribute to a successful interaction with the host. Whereas much effort has been made to uncover the molecular systems underlying this infection process, mechanisms of transcriptional regulation of the genes involved remain largely unknown. We performed the first systematic de-novo DNA motif discovery analysis in Phytophthora. To this end, we utilized the genome sequence of the late blight pathogen Phytophthora infestans and two related Phytophthora species (P. ramorum and P. sojae), as well as genome-wide in planta gene expression data to systematically predict 19 conserved DNA motifs. This catalog describes common eukaryotic promoter elements whose functionality is supported by the presence of orthologs of known general transcription factors. Together with strong functional enrichment of the common promoter elements towards effector genes involved in pathogenicity, we obtained a new and expanded picture of the promoter structure in P. infestans. More intriguingly, we identified specific DNA motifs that are either highly abundant or whose presence is significantly correlated with gene expression levels during infection. Several of these motifs are observed upstream of genes encoding transporters, RXLR effectors, but also transcriptional regulators. Motifs that are observed upstream of known pathogenicity-related genes are potentially important binding sites for transcription factors. Our analyses add substantial knowledge to the as of yet virtually unexplored question regarding general and specific gene regulation in this important class of pathogens. We propose hypotheses on the effects of cis-regulatory motifs on the gene regulation of pathogenicity-related genes and pinpoint motifs that are prime targets for further experimental validation
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