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Proteinová rodina HSP70 a její role v biotických interakcích
Čičmanec, Petr
Heat shock proteins 70 (HSP70s) are ubiquitous and widespread proteins across prokaryotic and eukaryotic organisms, and accumulated evidence indicates that these proteins are involved in much more than the response to heat shock. This thesis characterizes the role of HSP70s in response to different stimuli and provides insight into the HSP70's role in regulating the interaction between biotic and abiotic factors. The theoretical part summarizes the current knowledge of HSP70, including information about its structure, activity, posttranslational modifications, and the so-called chaperone code. It describes the functions of HSP70s and pays particular attention to the HSP70s' role in immunity and biotic interactions. The experimental part is divided into several sections. First, a bioinformatic analysis provides a cross-kingdom comparison of HSP70 and its role in biotic stress. This part is supplemented with the analysis of HSP70 distribution and abundance at the proteome level. Next, the effect of different stimuli on HSP70 protein abundance in different model organisms is presented, including E. coli, S. cerevisiae, A. thaliana, Pisum sativum, and Linum usitatissimum. Finally, the effects of the hsp70 mutation are analyzed, providing insight into the complexity of the HSP70 machinery and confirming its role in the biotic interaction between a model plant and fungi.
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Detection of bark beetle attack of Norway spruce using spectral and biophysical data at different hierarchical levels
Vesecká, Martina ; Albrechtová, Jana (advisor) ; Tomášková, Ivana (referee)
There was created an overview of key aspects for a correct understanding of the dynamics between bark beetle and Norway spruce, especially the way of life of the beetle and the time course of its life cycles. It is absolutely essential to understand this interaction for a timely and effective solution to the bark beetle calamity. Furthermore, the mutual interaction of beetle and tree is discussed in detail in the text. Great emphasis is placed on the description of the spruce's defense mechanisms and the consequences of the attack. In particular, biophysical changes in the needles, which cause a change in the spectral behaviour of the leaves and thus the entire forest stand. Using sensor capable of measuring the reflectance of surfaces, it is possible to detect a bark beetle-infested tree much earlier than changes in the needles could be detected by the naked eye and remove it while it is still colonized by the beetle and not spreading further into surrounding trees. This is key to managing not only the current bark beetle calamity. An overview of case studies is given in the thesis, where the use of spectral methods at different hierarchical levels was applied and satisfactory accuracy in the identification of early infested trees was achieved. Key words: Norway spruce, bark beetle, bark beetle...
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Connection between Unfolded Protein Response (UPR) and plant immunity
Kapr, Jan ; Burketová, Lenka (advisor) ; Vosolsobě, Stanislav (referee)
This bachelor thesis is concerned with the specific pathway in a response to endoplasmic reticulum stress in plant cells - the Unfolded Protein Response (UPR) and its role in plant immunity signalling. The work summarizes the main recent knowledges of molecular components of plant immunity and response to plant pathogens, focusing on important molecules that are also connected to UPR. The role of salicylic acid as a molecule on a crossroad between UPR signalling pathways and local and systemic resistence, is highlighted in this work. Recently, the phospholipids have also been shown to be important component of signaling pathways in response to biotic stress in plants and their role is also mentioned.
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Detection of Hsp70 protein in plants exposed to various stress factors.
Lengálová, Alžběta ; Hýsková, Veronika (advisor) ; Liberda, Jiří (referee)
! Plants are continuously exposed to various stress conditions. Being sessile, they are not able to escape from adverse conditions. Therefore, they have developed specific defence mechanisms. Most studies focus on plant responses to a single type of stress. However, plants in nature must cope with a variety of stresses at the same time. In this work, the effects of heat shock on the interaction of tabaco (Nicotiana tabacum L.) with the Potato virus Y (PVY) were investigated. Obviously, heat stress is associated with the synthesis of Hsp70 protein, which has many important functions alleviating adverse effects of stress conditions (e.g. Hsp70 participates in refolding or degradation of damaged proteins and protein syntetis de novo). The effect of Hsp70 during viral infection is still not fully understood, some studies revealed Hsp70 as a part of viral multiplication and transport processes in plant. In the first experiment performed in this work, higher levels of PVYNTN virus was found in tobacco plants that have been exposed to heat shock after inoculation than in plants only infected. The amount of the virus corresponded with the amount of Hsp70 protein detected immunochemically using a specific antibody. It seems that the plant response to combination of heat stress with viral infection is a...
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The effect of biotic stress on the metabolism of saccharides in tobacco plants (Nicotiana tabacum L.)
Kloudová, Kateřina ; Ryšlavá, Helena (advisor) ; Tichá, Marie (referee)
Plants have developed a number of ways how to minimise negative influence of the environment. As a consequence of stress action, plants carbohydrate metabolism is quite often influenced, esp. on the level of expression and activities of different enzymes and also several metabolites concentration. One of key enzymes of carbohydrate metabolism is invertase. The aim of this work was to find out, whether the activity of its isoforms (cytoplasmic, vacuolar and extracellular) in tobacco plants is influenced by Potato virus Y (PVY). It was shown, that activity of cytoplasmic invertase was not affected, but the activity of vacuolar and extracellular isoform was enhanced during potyviral infection. Hence, it is likely, that vacuolar and extracellular invertases are related to plant antiviral defence. The effect of PVY on other enzymes of carbohydrate metabolism and several metabolites content was studied. Activity of α-amylase and phosphorylase, starch-degrading enzymes, was strongly enhanced during potyviral infection. That is probably how plant cells get glucose, which is a key source of energy and metabolites for biosynthesis of different compounds. It may also serve as a signal molecule. Activity of other hydrolytic enzymes, β-glucosidase and β-hexosaminidase, was also slightly increased. There was no...
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Imaging of fluorescence emission signals from healthy and infected leaf tissues
BENEDIKTYOVÁ, Zuzana
Auto-fluorescence emission of plant tissues can be a powerful reporter on plant biochemistry and physiology since it originates in substances inherent to primary or secondary metabolism. Plant bodies contain a plethora of intrinsic fluorescent compounds emitting practically all wavelengths of visible light. Moreover, the spectrum of fluorescent reporter signals was recently extended by a variety of fluorescent proteins that provide a new tool to mark whole cells or sub-cellular structures, study protein localization and monitor gene expression and molecule interactions. The imaging of such fluorescence signals reveals a possibility to acquire the information from as many as millions of points simultaneously, in vivo and in a non-invasive way thereby preserving integrity of cells and whole organisms. Imaging is particularly suited to visualize heterogeneity such as a localized immune response to invading pathogens. It can be applied both at macro- as well as micro-scales in two and three dimensions. The recent advancement in microscopy, the multi-photon microscopy, has made possible to monitor fluorescence signals, such as NAD(P)H fluorescence from intact leaf interior, that have been hidden to single-photon techniques.
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