Les pectines de la paroi cellulaire végétale sont impliquées dans un grand nombre de processus physiologiques. Toutefois, la fonction exacte des pectines - au niveau structurel comme dans le contexte de la biologie et du développement cellulaire - est toujours un sujet de controverses. D’autre part, des observations soulèvent la question du rôle des fragments pectiques dans le contrôle de la floraison (Marfà et al., 1991) et les changements de communication intercellulaire observés au sein du méristème apical lors de la transition florale (Ormenese et al., 2000, 2002) impliquent des modifications biochimiques de la structure de la paroi cellulaire. Comme décrit par Liners et al. (1994), nous avons étudié par immunocytochimie (microscopie électronique et confocale) la nature, la localisation et le contenu en pectines dans des méristèmes de plantes de Sinapis en conditions végétatives ainsi que lors de la transition florale. Une diminution importante mais transitoire du contenu en homogalacturonanes de la paroi cellulaire est observée au cours des premières heures de la transition florale. Cette diminution du contenu en pectines doit être la conséquence d’une libération d’enzymes pectolytiques dont les pectine méthylestérases (PME) au niveau du méristème. Afin d’étudier l’expression des PME dans le méristème lors de la transition florale, nous avons produit et caractérisé un polysérum contre un zone extrêmement conservée des gènes de PME de S. alba./Immunocytochemical study of pectins and pectin modifications at floral transition in meristems of Sinapis alba L. By Stéphanie Sobry Abstract : Plant cell wall pectins are implicated in a large number of physiological processes. However, the exact functions of pectins – at a structural level as well as in the context of cell biology and development - are still debatable. On the other hand, observations raise the question as to whether pectic fragments are involved in the in vivo control of flowering (Marfà et al., 1991) and communication changes between the cells of the apical meristem in floral transition (Ormenese et al., 2000, 2002) imply biochemical modifications of the cell wall structure. Using immunocytochemistry (electron and confocal as described in Liners et al. (1994), we studied the nature, localization and content of pectins in meristems of Sinapis in vegetative plants and at floral transition. A marked but transient decrease of the homopolygalacturonic content of the cell wall occurs in the first hours of the transition to flowering. This pectin content decrease must be due to the release of pectolytic enzymes like pectin methylesterase (PME) in the meristem. To study PME expression in the meristem at floral transition, we raised and characterized polyclonal antibodies to highly conserved sequences of S. alba PME genes.

Artbildning, det vill säga uppkomst av nya arter, är ett centralt ämne inom evolutionsbiologinoch en process som kan fortskrida på ett flertal olika sätt. Reproduktiva barriärer som är nödvändiga för artbildningsprocessen kan utvecklas mellan populationer och verkar antingen så att individer hindras från att para sig med varandra (prezygotisk isolering) eller så att överlevnad eller reproduktionsframgång hos avkomman är reducerad (postzygotisk isolering).Syftet men där här studien är att först beskriva dessa olika typer av isoleringar och sedan summera den aktuella kunskapen om hur själva artbildningsprocessen kan fortgå. Avslutningvis beskrivs ett exempelsystem med tre geografiskt separerade populationer avarten skogsvitsvinge (Leptidea sinapis). Skillnader i kromosomantal och ekologi mellan vissa av populationerna kan potentiellt vara faktorer som har lett till begränsat genflöde och som i slutänden kan leda till att fullständigt reproduktivt isolerade arter uppkommer.

The environment can exert strong selective pressures on an organism. When selective pressures on traits differ between environments local adaptation may occur. If there is gene flow between the environments, local adaptation may be slowed or prevented. In plants, particularly weedy ephemerals, germination is a life-history trait that can be a strong determinant on fitness. In this dissertation, I explore the germination traits of two weedy Brassicaceae species, Arabidopsis thaliana and Sinapis arvensis, having populations in different habitats to determine whether germination traits within and between populations vary based on environmental conditions and to assess the extent of local adaptation. In Chapter 1, I assessed which genomic regions of A. thaliana were associated with differences in germination traits due to genotype-by-environment interactions. I performed a genome-wide association study using 100 natural accessions of A. thaliana under four light and nutrient combinations. I found 20 single nucleotide polymorphisms significantly associated with different environments, but none associated specifically with genotype-by-environment interactions. In Chapter 2, I assessed germination traits of S. arvensis collected from agricultural and non-agricultural habitats in the Bitterroot Valley of Montana. I discovered that the agricultural collection studied exhibited significantly different germination timing and amounts than the non-agricultural collections, which were statistically indistinguishable from each other. I also found evidence of a strong maternal effect on germination traits. In Chapter 3, I tested whether patterns of genetic variation between agricultural and non-agricultural collections of S. arvensis supported local adaptation to the two habitats even in the face of gene flow. While I expected to see some genetic differentiation between habitats, as seen in Chapter 2, no genetic differentiation was detected and markers putatively under selection were not associated with a particular habitat. I discuss why this might have occurred even though I have evidence for genetically-based phenotypic differentiation between agricultural and non-agricultural populations of S. arvensis. / text

Master thesis is focused on the monitoring and evaluation of the phytotoxicity of lea-chate of municipal solid waste landfill from Bukov. Introduction includes statistical data, waste management methods, legislation and terminology of waste management. Further, the thesis contains a description of the landfilling process with a focus on water monitoring, description of phytotoxicity tests and basic information about Bukov municipal solid waste landfill. Experiment is focused on phytotoxicity tests of leachate water from a given landfill. The final part contains the evaluation of the results and their in-terpretation.

Thesis on Phytotocity leachate from landfills Štěpánovice deals with basic concepts and legislation related to municipal waste and landfill in theoretical part. There are also procedures in waste management, their hierarchy, and statistical evaluation of the amount of multicipan waste. Another part of a literature search is aimed at monitoring water, general description of the storage process and general description of phytotoxicity. The practical part describes the process of solid municipal waste landfill Štěpánovice, its natural circumstances, locations and the integration in the territory. There is also described and discussed experiment which was realized by semi-chronic toxicity leachate method with white mustard (Sinapis alba L.). Followed by evaluation of the results and their interpretation in the current comparison of results with other writers.

Although transposable elements (TEs) have been subjected to detailed study in various organisms such as humans, maize, and drosophila, this is not the case for all organisms. Despite numerous studies on the effects of TEs in the field of evolution and functional genomics, there has not been many studies yet on how much variation these elements show in populations. To address these questions, we identified TEs in Leptidea sinapis based on a newly produced high-quality genome assembly and identified novel TEs in this project. In the first step of the project, we manually curated consensus sequences of the 150 most abundant TE subfamilies. We could identify 145 of these subfamilies: two of which were non-curatable because of bad consensus sequences, three that were uncertain where they start and end, and one of the subfamilies were divided into two different subfamilies. Hence, we ended up with 146 different TE subfamilies, and the remaining part of the project was carried out using these. In the second step, we examined how the manually curated 146 subfamilies were distributed in 83 different L. sinapis individuals in the Swedish population. Before performing manual curation for our selected TEs, we looked at the TE landscape of the long-read sequenced L. sinapis genome and showed that 58.2% of the L. sinapis genome consists of TEs. In a recent study, it has been shown that 40% of L. sinapis consists of TEs. So, when compared to previous studies, our result showed that the L. sinapis genome contained more TEs than previously reported. When we made the same analysis after manual curation, we showed that this amount increased to 62.4%. The distribution of classified TEs by groups is as follows: LINE 22.6%, DNA 7.43%, SINE 4.76%, LTR 3.10%.  After creating the final TE landscape for our reference genome, we analyzed 83 different individuals collected from different regions of Sweden such as Uppland, Östergötland, Västmanland, Närke, Värmland, Dalarna, Hälsingland, Småland, Medelpad, and Västerbotten for the individual number of non-reference insertions using RelocaTE2. We observed that these 146 subfamilies showed different distributions among individuals based on their sequence coverage. We couldn’t find any correlation between the number of insertions and the latitude of locations where individuals had been collected. When we look at the total number of insertions, we realized type I transposable elements were more abundant compared to type II transposable elements. Also, we checked the percentage of covered bases per individual in our dataset and observed that individuals with greater coverage had more TE insertions. After realizing this, when we analyzed individuals from different locations with very similar coverage, we could not see a significant correlation between the number of TE insertions and the latitude of locations of butterflies from different locations. For this reason, we can say that for the most abundant 146 TE subfamilies in the reference genome, there is not a significant difference between regions of Sweden. This study contributes to a better analysis of TE content in L. sinapis, and the know-how and possible problems with technical bias for individual TE insertion studies in general.

No description available.

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 4 uppsatser.

The relative amount of viral RNA of two comoviruses (RaMV and TuRSV) in different parts of plant during infection was determined. The two viruses were compared according to their ability to spread and multiply in plants.

The diploma thesis “The assessment of the phytotoxicity of sludge from selected sewage treatment plants“ deals with the current situation of the sludge treatment and disposal and the assessment of phytotoxicity of sewage treatment sludge. The sewage treatment sludge comes into existence during the process of sewage treatment. Nowadays is sludge landfilling from the point of view of nature protection and according to the legislation on the last place in a way of handling. Additionally, the thesis pays attention to the legislation related to the sewage treatment sludge and also statistical data concerning the production and the way of handling of the sewage treatment sludge. The practical part of the diploma thesis is focused on the description of two sewage treatment plants, namely Třebíč and Náměšť nad Oslavou. Subsequently were made several laboratory experiments with the sewage treatment sludge samples from the mentioned sewage treatment plants. At the sewage treatment sludge samples were assessed the phytotoxicity level by the testing set Phytotoxkit. Specifically was determined an inhibitive/stimulative effect on the growth of the root. The testing plant was a white mustard (Sinapis alba L.).