Publicação
Molecular regulation of flowering induction in Quercus suber
| Resumo: | In order to produce seeds, angiosperm plants need to first develop reproductive organs in a process known as flowering. Several prerequisites must be fulfilled to ensure that the development of flowers and the formation of seeds occur at an appropriate timing. A major stimuli involved in the flowering of plants include a previous exposure to cold in a process known as vernalization. In the model plant Arabidopsis thaliana, vernalization triggers the epigenetic repression of FLOWERING LOCUS C (FLC), a gene involved in the down-regulation of SUPPRESSOR OF OVERCONSTANS 1 (SOC1) and FLOWERING LOCUS T (FT). SOC1 and FT expression, in turn, induce flowering by up-regulating floral meristem identity genes. However, how this molecular mechanism is regulated in trees is still poorly understood. The recent sequencing of transcriptome of Quercus suber (cork oak), a monoecious species with great economic and ecological importance in the Mediterranean region, provided an important tool to study gene expression in this tree. It was intended with this work to unravel mechanisms of molecular regulation involved in the induction of flowering in Q. suber. Ten trees from Braga (Portugal) were monitored to analyze the influence of temperature and day-length in 2014 -- 2015 season. Additionally, samples of leaves and buds were periodically collected from selected trees to further study the temporal expression pattern of Q. suber genes predicted to be related to flowering time. Also, some of the samples were included in wax to later analyze the formation of the flower organs. Besides, bioinformatics analysis allowed the identification of Q. suber proteins homologs to proteins related to flowering time in other species. The putative function of these proteins was discussed regarding their homology with characterized proteins from different species, as well as their expression in male or female flowers of Q. suber. Moreover, A. thaliana transgenic lines overexpressing Q. suber transcripts potentially involved in flowering time were obtained and their phenotype analyzed. |
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| Autores principais: | Andrade, Luis Carlos Lopes de |
| Assunto: | Ciências Naturais::Ciências Biológicas |
| Ano: | 2015 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso restrito |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | In order to produce seeds, angiosperm plants need to first develop reproductive organs in a process known as flowering. Several prerequisites must be fulfilled to ensure that the development of flowers and the formation of seeds occur at an appropriate timing. A major stimuli involved in the flowering of plants include a previous exposure to cold in a process known as vernalization. In the model plant Arabidopsis thaliana, vernalization triggers the epigenetic repression of FLOWERING LOCUS C (FLC), a gene involved in the down-regulation of SUPPRESSOR OF OVERCONSTANS 1 (SOC1) and FLOWERING LOCUS T (FT). SOC1 and FT expression, in turn, induce flowering by up-regulating floral meristem identity genes. However, how this molecular mechanism is regulated in trees is still poorly understood. The recent sequencing of transcriptome of Quercus suber (cork oak), a monoecious species with great economic and ecological importance in the Mediterranean region, provided an important tool to study gene expression in this tree. It was intended with this work to unravel mechanisms of molecular regulation involved in the induction of flowering in Q. suber. Ten trees from Braga (Portugal) were monitored to analyze the influence of temperature and day-length in 2014 -- 2015 season. Additionally, samples of leaves and buds were periodically collected from selected trees to further study the temporal expression pattern of Q. suber genes predicted to be related to flowering time. Also, some of the samples were included in wax to later analyze the formation of the flower organs. Besides, bioinformatics analysis allowed the identification of Q. suber proteins homologs to proteins related to flowering time in other species. The putative function of these proteins was discussed regarding their homology with characterized proteins from different species, as well as their expression in male or female flowers of Q. suber. Moreover, A. thaliana transgenic lines overexpressing Q. suber transcripts potentially involved in flowering time were obtained and their phenotype analyzed. |
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