DELLA MUTATIONS IN PLANTS WITH SPECIAL EMPHASIS ON WHEAT

DELLA proteins are a subfamily of transcriptional regulators from the GRAS protein family. They act as growth repressors. Gibberellins (GA) promote growth by overcoming the DELLA-mediated growth restraint. A number of dominant mutations in highly conserved orthologous DELLA genes are known in various plant species. These mutations reduce plant height owing to production of more active forms of growth repressors. The aim of the current study is to estimate the genetic similarity of DELLA nucleotide and amino acid sequences stored in GenBank and to identify mutant and wild type alleles that encode DELLAs in modern Ukrainian winter bread wheat varieties. We have performed nucleotide and amino acid sequence search and alignment of the Rht-D1 wheat dwarfing gene and DELLA-encoding genes of other plant species with BLAST and MUSCLE software. A dendrogram illustrating phylogenetic relations among DELLA sequences of 35 plant species has been constructed using MEGA v5. In addition, PCR-based genotyping for the major wheat dwarfing genes Rht-B1 and Rht-D1 has been performed in wheat cultivars from different regions of Ukraine. It is shown that the mutant Rht-D1b allele is the commonest dwarfing allele among those tested in Ukrainian wheat cultivars (68 %), but its distribution over Ukraine is not random

Molecular Tools for Genebank Management and Evaluation

Molecular markers were developed for many species and enabled us to use them for the characterisation of genebank collections. We used the marker technology (microsatellites) for studying the genetic integrity of the self pollinating species wheat (Triticum aestivum L.) and the open pollinating species rye (Secale cereale L.). The study became possible, because at IPK both the ex situ collection, consisting of seeds from the most recent regeneration and a herbarium collection is maintained. In the herbarium collection from each accession samples of grains and complete spikes are deposited as vouchers when they are grown initially. For the wheat accessions investigated the comparison of the DNA fingerprints showed a high degree of idendity. No contamination due to foreign pollen or incorrect handling during the multiplication cycles was discovered. For the open pollinating species rye, however, major changes in allele frequencies were detected. Overall, nearly 50% of the alleles discovered in the original sample were not found in the material present in the ex situ collection now. In some cases alleles were detected in the most recently propagated subpopulations that were not observed in the investigated plants of the original one. In addition to the integrity studies we are in process of utilizing molecular markers for a marker assisted screening of genebank collections. Salt tolerance of barley has been shown as a case study in the present article

Molecular-genetic portrait of virulence of Stenotrophomonas maltophilia

Introduction. Stenotrophomonas maltophilia is an opportunistic pathogen that is intrinsically resistant to a wide range of antibiotics. The bacterium is associated with a number of serious diseases and makes a significant contribution to the pathogenesis of polymicrobial infections. S. maltophilia has a wide range of virulence factors, information about which is currently presented in the form of scattered and unconsolidated data. Purposes and objectives: critically analyze and summarize current data regarding the molecular-genetic aspects of S. maltophilia virulence for better understanding of the pathogenesis of infections associated with this pathogen. Materials and methods. An analysis of information from 80 modern literary sources devoted to the study of the virulent properties of S. maltophilia at the molecular-genetic level has been carried out. The analysis focuses on the mechanisms of production of virulence factors and their genetic determinants. Results.The molecular mechanisms of virulence that determine the infectious process caused by S. maltophilia have been analyzed and summarized, including the adhesive function of the surface structures of the bacterial cell (lipopolysaccharides, pili/fimbriae, flagella), the production of extracellular enzymes, the ability to form biofilms on abiotic surfaces and on the tissues of the macroorganism, the functioning of efflux pumps, secretion of small molecules into the external environment by the intercellular information exchange system Quorum Sensing, as well as the influence of iron metabolism on the virulence properties of S. maltophilia. Conclusion. The adaptation mechanisms that allow S. maltophilia to adapt to new habitat niches and survive in the human body and unfavorable environmental conditions have been poorly studied. An analytical review summarizing current information on the molecular-genetic aspects of S. maltophilia virulence will be of interest to clinicians and researchers studying the fundamental mechanisms of virulence

Evaluation of the potential accuracy of the pulsed radio signals source coordinate determination by the positioning system using a single UAV-sensor

An approach to determining the coordinates of pulsed radio signals sources by the positioningsystem in the application of a single unmanned aerial vehicles sensor is shown in this article. Therange-difference location method allows to determinate an informative coordinate parameter withoutretransmission and internal synchronization of receiving points. The result is achieved by improving thewell-known scientific and methodological apparatus with considering some features of the operationmode of pulsed radio signals sources. Presenting results of the simulation allow to estimate theinfluence of main input factors on the potential accuracy of the pulsed radio signal source coordinatedetermination

Состояние колонизационной резистентности у хирургических больных в раннем послеоперационном периоде

We have examined one of the main components of the mechanism of purulent-inflammation complications in surgical patients. It is normal microflora which reflects the condition of colonization resistance of the organism which is a leading mechanism of opposition to hospital infections. We have established changes of microflora of different biotopes of the organism in dependence on pathologic focus localization and of the period after the surgery. Complex approach to the investigation of colonization resistance allowed to discover not only dysbiotic changes but disturbances of some immunological mechanisms of total and local anti- infectious protection in surgical patients. It is desirable to combine selective decontamination with taking drugs which normalize indigenous micro-flora of the host (special diets, growth stimulators of normal microflora representatives, eubiotics) and immune-stimulating therapy.Исследован один из главных компонентов пускового механизма гнойно-воспалительных осложнений у хирургических больных - нормальная микрофлора, отражающая состояние колонизационной резистентности организма - ведущего защитного механизма противодействия госпитальным инфекциям. Установлены изменения микрофлоры различных биотопов организма больных в зависимости от локализации патологического очага и срока после операции. Комплексный подход к изучению колонизационной резистентности позволил выявить не только дисбиотические изменения, но и нарушения некоторых иммунных механизмов общей и местной противоинфекционной защиты у хирургических больных. Селективную деконтаминацию желательно сочетать с приемом препаратов, нормализующих индигенную микрофлору хозяина (специальные диеты, стимуляторы роста представителей нормальной флоры, назначение эубиотиков), и иммуностимулирующей терапией

The distribution of genetic diversity in a Brassica oleracea gene bank collection related to the effects on diversity of regeneration, as measured with AFLPs

The ex situ conservation of plant genetic resources in gene banks involves the selection of accessions to be conserved and the maintenance of these accessions for current and future users. Decisions concerning both these issues require knowledge about the distribution of genetic diversity within and between accessions sampled from the gene pool, but also about the changes in variation of these samples as a result of regenerations. These issues were studied in an existing gene bank collection of a cross-pollinating crop using a selection of groups of very similar Dutch white cabbage accessions, and additional groups of reference material representing the Dutch, and the global white cabbage gene pool. Six accessions were sampled both before and after a standard regeneration. 30 plants of each of 50 accessions plus 6 regeneration populations included in the study were characterised with AFLPs, using scores for 103 polymorphic bands. It was shown that the genetic changes as a result of standard gene bank regenerations, as measured by AFLPs, are of a comparable magnitude as the differences between some of the more similar accessions. The observed changes are mainly due to highly significant changes in allele frequencies for a few fragments, whereas for the majority of fragments the alleles occur in similar frequencies before and after regeneration. It is argued that, given the changes of accessions over generations, accessions that display similar levels of differentiation may be combined safely

Comparative expression of Cbf genes in the Triticeae under different acclimation induction temperatures

In plants, the C-repeat binding factors (Cbfs) are believed to regulate low-temperature (LT) tolerance. However, most functional studies of Cbfs have focused on characterizing expression after an LT shock and have not quantified differences associated with variable temperature induction or the rate of response to LT treatment. In the Triticeae, rye (Secale cereale L.) is one of the most LT-tolerant species, and is an excellent model to study and compare Cbf LT induction and expression profiles. Here, we report the isolation of rye Cbf genes (ScCbfs) and compare their expression levels in spring- and winter-habit rye cultivars and their orthologs in two winter-habit wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) cultivars. Eleven ScCbfs were isolated spanning all four major phylogenetic groups. Nine of the ScCbfs mapped to 5RL and one to chromosome 2R. Cbf expression levels were variable, with stronger expression in winter- versus spring-habit rye cultivars but no clear relationship with cultivar differences in LT, down-stream cold-regulated gene expression and Cbf expression were detected. Some Cbfs were expressed only at warmer acclimation temperatures in all three species and their expression was repressed at the end of an 8-h dark period at warmer temperatures, which may reflect a temperature-dependent, light-regulated diurnal response. Our work indicates that Cbf expression is regulated by complex genotype by time by induction–temperature interactions, emphasizing that sample timing, induction–temperature and light-related factors must receive greater consideration in future studies involving functional characterization of LT-induced genes in cereals