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Control of lateral root development in response to availability of principal mineral nutrients.
Halamková, Daniela ; Tylová, Edita (advisor) ; Smetana, Ondřej (referee)
Lateral roots are, due to their large absorption surface, a part of the root system with significant importance for the plant's ingestion of water and nutrients. Their development depends on heterogeneity of soil environment, which enables the plant to optimize the acquisition of resources under current conditions. The availability of mineral nutrients (type of nutrient, form, distribution in soil and mobility) is one of key factors that determine root system morphogenesis. Another important aspect is the amount of nutrient in the plant; in other words, the plant's current demand for the element. The most important nutrients that influence the architecture of the root system are two macroelements - nitrogen and phosphorus. Both of these elements trigger positive and negative effects on the development of lateral roots. Nitrate, important source of nitrogen, induces two entirely different regulatory mechanisms of lateral root development. Under nitrogen limiting condition, a local stimulation of lateral root elongation is triggered in nitrate-rich patches. This response integrates the signalling pathways of auxin and nitrate. In contrast, high and homogenous availability of nitrate in rhizosphere (≥ 10 mM) causes inhibition of lateral root growth. This systemic inhibitory effect was similarly...
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Closer analysis of gene trap line MGT180 and its candidate genes
Šnajdrová, Tereza ; Soukup, Aleš (advisor) ; Klíma, Petr (referee)
Root branching allows plants to explore rhizosphere, to gain efficiently water, mineral nutrients or enter in various biotic interactions. Initiation of lateral root formation is localized to pericycle cells, flanking the xylem poles of diarch vascular bundle in Arabidopsis thaliana. Right in these pericycle cells, there is the expression pattern of the gene trap line MGT180. In this theseis , I have provided the evidence that the expression pattern of MGT180 is related with AT-HOOK MOTIF CONTAINING NUCLEAR LOCALIZED18 (AHL18; At3g60870). AHL18 belongs to a gene family of 29 transcriptional factors of Arabidopsis. AHL18 has not been functionally characterized yet, the analysis of singlemutant ahl18 and some others revealed no significant phenotype. However, one of doublemutants, E15, showed a significant phenotype. This phenotype was evident mainly in the aboveground part of plants, and was not corresponding to any phenotype of AHL mutation described so far. There is a known redundancy among some AHL genes, confirmed by crossing of ahl18 and ahl28 leading to E15 plant. Translation phusion AHL18-mRUBY and AHL22-mRUBY under native promotors should reveal, where these two related proteins act, and if they fiction in autonomous manner or not. Key words Arabidopsis thaliana, lateral root, AHL, pericycle
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Lateral root and their origin
Nováková, Hana ; Soukup, Aleš (advisor) ; Sekereš, Juraj (referee)
The origin of lateral roots is one of the determinants of the structure of the overall architecture of the root system of plants. Individual plant species differs in point of initiation of lateral roots in the longitudinal and transverse plane of the parent root. This paper briefly summarizes the findings relating to the establishment and development of lateral roots in the model of plant Arabidopsis thaliana and on the sample of several species of ferns and monocots and dicots of literature outlines the variability that manifests itself especially during initiation of lateral roots. The ferns initiation site located in the endodermis of the parent root, for other species to form the lateral root primordium of pericycle cells that are found in a certain position in relation to vascular elements in the central cylinder of the parent root. Another highly variable factor in the development of lateral root initiation site is the distance from the root apical meristem, which is related to the place of the auxin signal competent cells and also the rate of growth and progress of cells from the parent root apical meristem. Powered by TCPDF (www.tcpdf.org)
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Closer analysis of gene trap line MGT180 and its candidate genes
Šnajdrová, Tereza ; Soukup, Aleš (advisor) ; Klíma, Petr (referee)
Root branching allows plants to explore rhizosphere, to gain efficiently water, mineral nutrients or enter in various biotic interactions. Initiation of lateral root formation is localized to pericycle cells, flanking the xylem poles of diarch vascular bundle in Arabidopsis thaliana. Right in these pericycle cells, there is the expression pattern of the gene trap line MGT180. In this theseis , I have provided the evidence that the expression pattern of MGT180 is related with AT-HOOK MOTIF CONTAINING NUCLEAR LOCALIZED18 (AHL18; At3g60870). AHL18 belongs to a gene family of 29 transcriptional factors of Arabidopsis. AHL18 has not been functionally characterized yet, the analysis of singlemutant ahl18 and some others revealed no significant phenotype. However, one of doublemutants, E15, showed a significant phenotype. This phenotype was evident mainly in the aboveground part of plants, and was not corresponding to any phenotype of AHL mutation described so far. There is a known redundancy among some AHL genes, confirmed by crossing of ahl18 and ahl28 leading to E15 plant. Translation phusion AHL18-mRUBY and AHL22-mRUBY under native promotors should reveal, where these two related proteins act, and if they fiction in autonomous manner or not. Key words Arabidopsis thaliana, lateral root, AHL, pericycle
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Lateral root and their origin
Nováková, Hana ; Soukup, Aleš (advisor) ; Sekereš, Juraj (referee)
The origin of lateral roots is one of the determinants of the structure of the overall architecture of the root system of plants. Individual plant species differs in point of initiation of lateral roots in the longitudinal and transverse plane of the parent root. This paper briefly summarizes the findings relating to the establishment and development of lateral roots in the model of plant Arabidopsis thaliana and on the sample of several species of ferns and monocots and dicots of literature outlines the variability that manifests itself especially during initiation of lateral roots. The ferns initiation site located in the endodermis of the parent root, for other species to form the lateral root primordium of pericycle cells that are found in a certain position in relation to vascular elements in the central cylinder of the parent root. Another highly variable factor in the development of lateral root initiation site is the distance from the root apical meristem, which is related to the place of the auxin signal competent cells and also the rate of growth and progress of cells from the parent root apical meristem. Powered by TCPDF (www.tcpdf.org)
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Funkce genů rodiny TTL a jejich efekt na tvorbu postranních kořenů u Arabidopsis
Hilgert Delgado, Alois Antonín ; Soukup, Aleš (advisor) ; Cvrčková, Fatima (referee)
The work is focused on the lateral roots, which are an indispensable part of the root system and play a key role in communication with rhizosphere and the efficient exploitation of natural resources. Tetratricopeptide-repeat Thioredoxin-like 3 gene (TTL3) was identified by forward screening based on its gene expression pattern in the search for genes associated with the development of lateral roots in Arabidopsis thaliana. TTL3 also known as VIT (VH1 interacting TPR containing protein), belongs to a family of four paralogues in Arabidopsis showing a very similar arrangement of domains. It seems that this type of proteins is widespread in plants and provides protein-protein signaling as an important component of phytohormone response pathways. The presented diploma thesis is focused on characterization and comparison of expression patterns of the four members of TTL family, through creation of pTTL::uidA (GUS) transcriptional fusions. The promoter area was estimated to be contained in about 2000bp upwards the TTLs coding sequences and transcriptional fusions with uidA gene were individually constructed and transformed into Arabidopsis via Agrobacterium tumefaciens. The expression patterns of analyzed genes were microscopically confirmed and allowed comparison among members of TTL gene family with regard...
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Lateral roots and root nodules - similarities and differences
Šnajdrová, Tereza ; Soukup, Aleš (advisor) ; Kulich, Ivan (referee)
Postranní orgány kořene, kořenové hlízky a postranní kořeny, se zakládají endogenně, a až na výjimky mimo apikální meristém. Tyto orgány mohou být různě modifikovány. Některé rostliny mají, právě díky těmto postranním orgánům, schopnost vstupovat do symbiotických interakcí s jinými organismy. Při vzniku symbiotické, dusík-fixující hlízky se uplatňuje signalizace obou budoucích partnerů, aby byl zajištěn vstup do kořene pouze organismu hostitelsky specifickému k rostlině. Pronikání bakterie Rhizobium či Frankia do kořene se standardně děje přes kořenový vlásek pokožkové buňky, ale není to jediný možný mechanismus vstupu. Zároveň s tímto vstupem se začne vytvářet hlízkové primordium. Pletivo, z něhož se hlízka vytváří, i výsledná podoba hlízky, se liší u různých rostlin. V centrální zóně dospělé hlízky dochází, díky nitrát reduktáze, k fixaci vzdušného dusíku. Tato vlastnost zvýhodňuje rostliny, schopné této hlízkové symbiózy, při kolonizaci půdy, chudé na dusík. Postranní kořeny se zakládají v pericyklu, aktivací malého počtu jeho buněk. Po výstupu z pletiv mateřského kořene dochází k aktivaci meristému bočního kořene. Oba tyto postranní orgány spolu s primárním kořenem tvoří dynamický kořenový systém, regulovaný vnitřními i vnějšími faktory.
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Control of lateral root development in response to availability of principal mineral nutrients.
Halamková, Daniela ; Tylová, Edita (advisor) ; Smetana, Ondřej (referee)
Lateral roots are, due to their large absorption surface, a part of the root system with significant importance for the plant's ingestion of water and nutrients. Their development depends on heterogeneity of soil environment, which enables the plant to optimize the acquisition of resources under current conditions. The availability of mineral nutrients (type of nutrient, form, distribution in soil and mobility) is one of key factors that determine root system morphogenesis. Another important aspect is the amount of nutrient in the plant; in other words, the plant's current demand for the element. The most important nutrients that influence the architecture of the root system are two macroelements - nitrogen and phosphorus. Both of these elements trigger positive and negative effects on the development of lateral roots. Nitrate, important source of nitrogen, induces two entirely different regulatory mechanisms of lateral root development. Under nitrogen limiting condition, a local stimulation of lateral root elongation is triggered in nitrate-rich patches. This response integrates the signalling pathways of auxin and nitrate. In contrast, high and homogenous availability of nitrate in rhizosphere (≥ 10 mM) causes inhibition of lateral root growth. This systemic inhibitory effect was similarly...
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