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Studium funkce AtAFB4
Zelinka, Radim
Despite the fact, that research on apical dominance started before more than 100 years ago, this economically important phenomenon is not fully understood yet. One of the genes involved in this regulation in the model plant Pisum sativum is PsMS2, that was cloned recently and it came out i tis an ortholog of the auxin F-box receptor AtAFB4. The aim of this bachelor thesis was to prepare hybrids of the Arabidopsis mutant afb4 with plants expressing the GFP gene for green fluorescent protein fused to genes of the PIN family (1,2,3,4,7) under native promoters. T1 plans from all five crosses were test-ed preliminary using the selection gene for resistance to the herbicide sulphadiazine contained in the genome of male plants and more than 50 % of T1 plants from all lines survived without any symptoms of damage. In further cultivation of the surviving plants strong phenotype resembling the afb4 mutation of the male plants was observed in all plants. From the above-mentioned facts we can conclude that we have obtained hybrids bearing the intended genetic information. These prepared plants will be used in further studies on the influence of the afb4 mutation on the changes of PIN membrane transporters and further characteristics, like changes in auxin transport, reaction to exogenous application of auxin and strigolactone, etc.
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Role cytokininů v regulaci vyrůstání pupenů hrachu
Vetter, Martin
The diploma thesis was aimed to explain the role of cytokinins in regulation of cotyledonary bud outgrowth in pea (Pisum sativum L.). Decapitation of the apex and subsequent application of IAA lanolin paste containing also BAP caused increased expression of genes PsDRM1 and PsBRC1 associated with dormancy. It suggests that cytokinins may have effect on the amount of transported auxin in the major stem. Application of cytokinin to the cotyledonary buds of intact plants activated their outgrowth. Imunolocalization showed polarization of PIN1 proteins in the treated buds, on contrary to untreated buds. It means that cytokinin directly influenced polarization of PIN1 proteins and the subsequent canalization of the polar auxin transport.
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Využitie muntantov ramosus pri štúdiu fytohormonálnej regulácie vetvenia stonky u hrachu
Polko, Peter
This thesis deals with effect of phytohormonal application on apical dominance, stem anatomy and expression of PsPIN1 in garden pea (Pisum sativum) variety Paloma and from this variety derived mutant rms4. In this thesis effect of decapitation, exogenous application of auxin (IAA, in a form of lanoline paste) and strigolactone (GR24, in a form of admixture in nutrient solution) on growth activity of axillary buds from nodes 1st to 4th was studied. After decapitation (above 4th node) "wild-type" plants reacted by increased intensity of axillary buds growth in almost all observed nodes and application of IAA inhibited growth of axillary buds to level of intact plants. In rms4 plants response on decapitation was only observed in axillary buds of the 4th node along with there was observation of insensivity to IAA in other observed nodes. GR24 inhibited growth of axillary buds in a small extent in "wild-type" plants and in rms4 mutants there was no observation of this inhibitory effect of strigolactone. Furthermore this thesis deals with effect of decapitation on [3H] - IAA transport from axillary bud in to young plants stems. Polar auxin transport capacity in stem is slightly higher in rms4 mutant and after decapitation axillary buds exported more auxin compared to "wild-type" plants. De novo vascular differentiation was observed 5 days after application of IAA in stem of both genotypes. Expression of PsPIN1 increased after IAA treatment both in Paloma and in rms4 mutant. This increase was higher in rms4 mutant compared to variety Paloma.
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Vliv transportu auxinu na regulaci vyrůstání kotylárních pupenů hrachu
Macoszek, Ondřej
The diploma thesis was aimed on role of polar auxin transport in regulation of cotyledonary bud outgrowth in pea plants (Pisum sativum L.) in relation to competitive canalization of auxin sources. Decapitation of growth apex, as primary source of auxin, causes release of cotyledonary buds from inhibition. This was followed by increased expression of genes for auxin transport proteins PsPIN1 and PsAUX1 and decrease in PsDRM1 and PsBR1 gene expression that are related to dormant state of plant tissues. In the next phase, different types of exogenous auxin application on decapitated stumps and cotyledonary bud growth dynamic were carried out. Auxin application on decapiteded stump caused inhibition of cotyledonary bud growth, its application on right or left side of the stump inhibits cotyledonary bud on the side of application. If auxin on the both sides of stump was applied, cotyledonary bud growth was not inhibited, on contrary to their separation with a plastic sheet, which resulted in significant growth inhibition of both buds. In case of both-sided application, these sources of auxin prevents each other in canalization. If these two sources of auxin were separated with a plastic sheet, canalization of auxin flow was observed and two independent auxin channels were formed. Analogy of this competition can be expected in the case of cotyledonary buds, as two potential auxin sources.
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Analyzing the complexity of auxin-related processes and their regulation
Simon, Sibu ; Zažímalová, Eva (advisor) ; Stiborová, Marie (referee) ; Pavlíček, Jiří (referee)
Phytohormone auxin plays an important role in various aspects of plant growth and development. The necessary concentration maxima at the region of its action are achieved by auxin metabolism, passive diffusion of auxin molecules across plasma membrane and by the carrier-mediated auxin transport, as well as by modulation of these processes. In our study we used a group of compounds structurally related to major endogenous auxin indole-3-acetic acid, as well as synthetic auxins 2,4-dichlorophenoxy acetic acid (2,4- D) and naphthalene-1-acetic acid (NAA). We aimed to characterize the auxin specificity of developmentally important processes such as carrier-mediated auxin transport, and 'genomic' (transcriptional) and 'non-genomic' (transcriptional) auxin signaling. In addition to the characterization of these compounds we also hoped to get an insight into the complex regulatory mechanism of auxin-related processes and to possibly find a particular compound with distinct behavior towards particular processes. By making use of such compounds and other molecular tools we aimed to analyze the mechanism of 'non-genomic' auxin signaling, to understand the mode of action of FM (Fei Mao) styryl dyes on the dynamics of membrane- localized auxin transporters, and to study the involvement of other phytohormones...
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The role of AGC protein kinases in the regulation of auxin transport
Martincová, Marie ; Petrášek, Jan (advisor) ; Opatrný, Zdeněk (referee)
There are several members of the subfamily of plant AGC kinases (AGCVIII) suggested to play a role in the regulation of auxin transport, protein kinases PID, WAG1, WAG2 and D6. They all have been shown to perform regulatory phosphorylation of PIN auxin efflux carriers. It is the asymmetrical subcellular localization of PIN proteins that enables the auxin molecules to be transported through a tissue in a polar manner. Regulation of their expression, localization or activity can therefore affect the quantity and directionality of auxin transport. This thesis is focused on better understanding of the PID-mediated regulation of auxin transport. The auxin accumulation as well as the localization of PIN and PID proteins has been studied using stable and transient expression of Arabidopsis thaliana PID in tobacco cell line BY-2. As shown here, the activity of PID does not enhance the activity of PINs, but still it has a positive effect on auxin efflux by increasing the amount of PIN proteins on the plasma membrane. Results presented here suggest that PID-mediated phosphorylation of PIN proteins most likely promotes their exocytosis from endosomal compartments towards the plasma membrane. Using transient co-expression of PID kinase mutated in its ATP-binding site and PIN1-RFP it was shown that functional...
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Role RMS2 v regulaci apikální dominance
Hiršová, Veronika
The role of RMS2 in regulation of apical dominance was studied with the use of rms2 mutants and wild type cv. Torsdag. Phenotypic changes and changes in polar auxin transport (by imunnolocalization of PIN1) in rms2 mutants and after auxin application were observed. The phenotypic changes of rms2 mutants against cv. Torsdag are enhanced branching from the first two nodes but much less than branching of strigolactone deficient mutants. Auxin application both on intact and decapitated rms2 mutants led to enhancement of growth of the buds adjacent to the place of application in contrary to wild type in that the application inhibits the growth of adjacent buds. Auxin application to the cut surface of decapitated stem or from the side of the stem led in the primary application always to canalization. Secondary application 24 hours later led to canalization only in rms2. Originally proposed feedback regulation of RMS1 expression by RMS2 was changed to RMS2 as being a negative regulator of polar auxin transport.
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