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Variability and mechanisms of exodermis differentiation in plant roots
Blascheová, Zuzana ; Tylová, Edita (advisor) ; Konrádová, Hana (referee)
Environmental conditions affect the formation of apoplastic barriers (endodermis and exodermis) in roots. This was shown on many species in many research papers. The exodermal layer is more variable in response to stress conditions than endodermal layer. Cadmium toxicity, as many other stresses, induces faster development of apoplastic barriers. Most of research papers published so far, however characterized only the response of main root to this type of stress factor. Lateral roots, an important part of the root system absorptive surface, are neglected and there is not much information about their response to cadmium stress. The pattern of apoplastic barriers development was therefore analysed in main and also in lateral roots of various size and position on maternal root axis. We found significant differences in response to cadmium stress among these different root types. Then we summed up the differences between these types of roots. Short lateral roots were generally more responsive to cadmium stress, cadmium affected root branching as well as differentiation of apoplastic barriers in lateral roots. These results help us to better understand the response of complex roots system to environmental conditions. In the second part of this work, the role of CASP genes in exodermal development was...
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Lateral root development in response to mineral nutrients; signal mechanisms and pathways.
Halamková, Daniela ; Tylová, Edita (advisor) ; Lhotáková, Zuzana (referee)
TTL3 gene was identified by forward screening of genes involved in lateral root development in Arabidopsis thaliana based on its expression pattern. TTL3 belongs to the TTL (TETRATRICOPEPTIDE-REPEAT THIOREDOXIN-LIKE) gene family. The diploma thesis is aimed on characterisation of changes in TTL1, TTL3 a TTL4 promotor activities in response to external conditions (availability of nitrogen or phosphorus) that affect root growth. Obtained data should elucidate possible relation among TTL gene expression activities, root growth rate, and apical meristem activity. Nitrogen or phosphorus deficiency triggered changes in root growth and root system morphology of experimental plants. Short-term nitrogen deficiency stimulated root growth. Short-term phosphorus deficiency induced gradual growth cessation in main root and long laterals. Long-term deficiency reduced root growth of both N-deficient and P-deficient plants compared to control. The root system size of N-deficient and P-deficient plant was almost similar. Determination of promotor activity using β-glucuronidase reporter gene showed changes in expression activity and its localization in response to root growth intensity. TTL4 gene promotor activity was the most responsive. Its activity was generally higher in slowly growing roots, particularly under...
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Variability and mechanisms of exodermis differentiation in plant roots
Blascheová, Zuzana ; Tylová, Edita (advisor) ; Konrádová, Hana (referee)
Environmental conditions affect the formation of apoplastic barriers (endodermis and exodermis) in roots. This was shown on many species in many research papers. The exodermal layer is more variable in response to stress conditions than endodermal layer. Cadmium toxicity, as many other stresses, induces faster development of apoplastic barriers. Most of research papers published so far, however characterized only the response of main root to this type of stress factor. Lateral roots, an important part of the root system absorptive surface, are neglected and there is not much information about their response to cadmium stress. The pattern of apoplastic barriers development was therefore analysed in main and also in lateral roots of various size and position on maternal root axis. We found significant differences in response to cadmium stress among these different root types. Then we summed up the differences between these types of roots. Short lateral roots were generally more responsive to cadmium stress, cadmium affected root branching as well as differentiation of apoplastic barriers in lateral roots. These results help us to better understand the response of complex roots system to environmental conditions. In the second part of this work, the role of CASP genes in exodermal development was...
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Lateral root development in response to mineral nutrients; signal mechanisms and pathways.
Halamková, Daniela ; Tylová, Edita (advisor) ; Lhotáková, Zuzana (referee)
TTL3 gene was identified by forward screening of genes involved in lateral root development in Arabidopsis thaliana based on its expression pattern. TTL3 belongs to the TTL (TETRATRICOPEPTIDE-REPEAT THIOREDOXIN-LIKE) gene family. The diploma thesis is aimed on characterisation of changes in TTL1, TTL3 a TTL4 promotor activities in response to external conditions (availability of nitrogen or phosphorus) that affect root growth. Obtained data should elucidate possible relation among TTL gene expression activities, root growth rate, and apical meristem activity. Nitrogen or phosphorus deficiency triggered changes in root growth and root system morphology of experimental plants. Short-term nitrogen deficiency stimulated root growth. Short-term phosphorus deficiency induced gradual growth cessation in main root and long laterals. Long-term deficiency reduced root growth of both N-deficient and P-deficient plants compared to control. The root system size of N-deficient and P-deficient plant was almost similar. Determination of promotor activity using β-glucuronidase reporter gene showed changes in expression activity and its localization in response to root growth intensity. TTL4 gene promotor activity was the most responsive. Its activity was generally higher in slowly growing roots, particularly under...
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