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Structural modification of the root cortex in response to environmental conditions
Lehmannová, Justýna ; Tylová, Edita (advisor) ; Albrechtová, Jana (referee)
Plants encounter many adverse factors in their environment to which they must adapt in order to make effective use of their environment despite stresses such as water shortage, nutrient deficiency, soil salinization, soil compaction or flooding. This work focuses on the internal structure of the root and its changes in response to environmental stress conditions. Specifically, it focuses on structural modifications of the middle part of the root cortex, which play an important role in optimizing root system functions under stress conditions. It summarizes knowledge on the structure, mode of formation and regulatory mechanisms of aerenchyma formation, which is of great importance for plant survival under hypoxic conditions. These are encountered by many plants in flooded areas, including important agricultural crops such as rice and maize. This paper also analyses the role of aerenchyma in response to other stress factors such as nutrient deficiency, water deficit or substrate compaction. In addition, this work focuses on lesser-known structural modifications of the middle part of the cortex, whose function has not yet been fully understood, but which represent potentially important characteristics of the root system that could be the focus of future breeding of resistant crop cultivars. These...
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Lignin and lignification mechanisms
Gargoš, Ondřej ; Tylová, Edita (advisor) ; Schwarzerová, Kateřina (referee)
Lignin is an essential compound of all vascular plants. Recent studies have also shown its presence in non-vascular plants. Lignin is important for plant growth and development, provides a mechanical support to plant tissues and is also a major player in the response of plants to various stresses. Lignin is an aromatic heteropolymer and comprises classical lignin units - guaiacyl (G), syringyl (S) and p-hydroxyfenyl (H). The amount and ratio of these lignin units varies among plant species, organs and cell types. Nontraditional monomer units that can be deposited in lignin also increase the variety of lignin. Lignification, i.e. the formation and deposition of lignin, is a complex and precisely controlled process involving the synthesis of monolignols in the cytoplasm, their transport into the cell wall and subsequent polymerization. A number of enzymes are involved in the lignification process, and recent studies are gradually revealing the mechanisms of lignification regulation in various cells of plant body. This bachelor thesis summarizes the knowledge of the importance, synthesis and deposition of lignin, and also compares the mechanisms regulating lignification in different types of plant cells - tracheary elements, sclerenchyma and endodermal cells. An interesting phenomenon of lignification...
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Lignin and lignification mechanisms
Gargoš, Ondřej ; Tylová, Edita (advisor) ; Schwarzerová, Kateřina (referee)
Lignin is an essential compound of all vascular plants. Recent studies have also shown its presence in non-vascular plants. Lignin is important for plant growth and development, provides a mechanical support to plant tissues and is also a major player in the response of plants to various stresses. Lignin is an aromatic heteropolymer and comprises classical lignin units - guaiacyl (G), syringyl (S) and p-hydroxyfenyl (H). The amount and ratio of these lignin units varies among plant species, organs and cell types. Nontraditional monomer units that can be deposited in lignin also increase the variety of lignin. Lignification, i.e. the formation and deposition of lignin, is a complex and precisely controlled process involving the synthesis of monolignols in the cytoplasm, their transport into the cell wall and subsequent polymerization. A number of enzymes are involved in the lignification process, and recent studies are gradually revealing the mechanisms of lignification regulation in various cells of plant body. This bachelor thesis summarizes the knowledge of the importance, synthesis and deposition of lignin, and also compares the mechanisms regulating lignification in different types of plant cells - tracheary elements, sclerenchyma and endodermal cells. An interesting phenomenon of lignification...
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