Papel funcional de microRNAs na arquitetura vegetativa e radicular de plantas
Carregando...
Arquivos
Data
2013-06-19
Autores
Morea, Edna Gicela Ortiz [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Os MicroRNAs (miRNAs) são pequenos RNAs endógenos não codantes de 20-22 nucleotídeos (nt) que regulam a expressão gênica de genes-alvos. Eles estão envolvidos em diversos aspectos de desenvolvimento da planta, tanto na parte aérea, quanto no sistema radicular. Os miRNAs e seus genesalvos tem uma complementariedade quase perfeita em plantas, sendo que esta complementaridade está relacionada à origem dos genes de miRNAs (genes MIRs). A hipótese mais aceita para a origem dos genes de miRNAs é a “hipótese de duplicação invertida”, a qual propõe que os genes de miRNAs surgiram a partir de duplicações invertidas do seus genes-alvos nos genomas vegetais. Muitos genes-alvos de miRNA em plantas codificam para fatores de transcrição, tais como os genes SQUAMOSA Promoter-Binding Protein-Like (SPLs). Alguns membros da família SPL são regulados por ambos os miRNAs, miR156 e miR529. O sítio de reconhecimento destes microRNAs em transcritos de genes SPLs é conservado e difere somente por sete nucleotídeos. Enquanto o miR156 é altamente conservado entre Angiospermas, incluindo arabidopsis, o miR529 aparentemente está presente somente em eudicotiledôneas basais, monocotiledôneas e no musgo Physcomitrella patens. Neste trabalho, foram realizadas duas abordagens para o estudo da via miRNAs/SPL. Na primeira abordagem, foi analisada a evolução e a possível função da via miR529/SPL em monocotiledôneas e eudicotiledôneas. Foi testado o sítio de reconhecimento do miR529b em dois genes SPLs (SPL9 e SPL15) de arabidopsis encontrados bioinformaticamente via geração de plantas transgênicas de arabidopsis superexpressando o precursor de arroz OsMIR529b. As linhagens transgênicas de arabidopsis (OsMIR529b-OE) apresentaram fenótipos vegetativos e reprodutivos similares aos de plantas duplo mutantes de perda de função para os genes SPL9 e SPL15 de arabidopsis (denominado spl9/spl15). Estes...
MicroRNAs (miRNAs) are endogenous small non-coding RNAs of 20-22 nucleotides (nt) in length that regulate the gene expression transcriptionally and posttranscriptionally. They are involved in many aspects of plant development, both in the shoot and in the root systems. MiRNAs and their target genes have an almost perfect complementarily in plants, and this is related to the complementarity of genes origin of miRNAs genes (MIR genes). The most accepted hypothesis for the origin of miRNA genes is the inverted duplication hypothesis, which proposes that genes of miRNAs arose from inverted duplications of their target genes in plant genomes. Many miRNA target genes in plants encode transcription factors such as SQUAMOSA Promoter-Binding Protein-Like (SPLs). Some SPL family members SPL are regulated by both miRNAs, miR156 and miR529. The recognition site for these microRNAs in SPL transcripts is conserved and only differs by seven nucleotides. While miR156 is highly conserved among Angiosperms, including Arabidopsis thaliana, miR529 is apparently present only in basal eudicots, monocots and in the moss Physcomitrella patens. In this work, were performed two approaches to study miRNA-direct SPL gene regulation. In the first approach, we analyzed the evolution and possible function of the miR529/SPL pathway in monocots and eudicotyledonous. We searched for miR529b recognition sites in SPL genes from core eudicots, such as Arabidopsis thaliana. Interestingly, we found two miR529b-targeted SPLs (SPL9 and SPL15) in Arabidopsis and showed that the recognition sites are functional via the generation of transgenic Arabidopsis plants overexpressing OsMIR529b. OsMIR529b-OE overpressors are phenotipically and molecularly similar to the double mutant spl9/spl15. Our data suggest that miR529b is processed and functional in core eudicots and that this microRNA was recently lost in the evolutionary history of the ...
MicroRNAs (miRNAs) are endogenous small non-coding RNAs of 20-22 nucleotides (nt) in length that regulate the gene expression transcriptionally and posttranscriptionally. They are involved in many aspects of plant development, both in the shoot and in the root systems. MiRNAs and their target genes have an almost perfect complementarily in plants, and this is related to the complementarity of genes origin of miRNAs genes (MIR genes). The most accepted hypothesis for the origin of miRNA genes is the inverted duplication hypothesis, which proposes that genes of miRNAs arose from inverted duplications of their target genes in plant genomes. Many miRNA target genes in plants encode transcription factors such as SQUAMOSA Promoter-Binding Protein-Like (SPLs). Some SPL family members SPL are regulated by both miRNAs, miR156 and miR529. The recognition site for these microRNAs in SPL transcripts is conserved and only differs by seven nucleotides. While miR156 is highly conserved among Angiosperms, including Arabidopsis thaliana, miR529 is apparently present only in basal eudicots, monocots and in the moss Physcomitrella patens. In this work, were performed two approaches to study miRNA-direct SPL gene regulation. In the first approach, we analyzed the evolution and possible function of the miR529/SPL pathway in monocots and eudicotyledonous. We searched for miR529b recognition sites in SPL genes from core eudicots, such as Arabidopsis thaliana. Interestingly, we found two miR529b-targeted SPLs (SPL9 and SPL15) in Arabidopsis and showed that the recognition sites are functional via the generation of transgenic Arabidopsis plants overexpressing OsMIR529b. OsMIR529b-OE overpressors are phenotipically and molecularly similar to the double mutant spl9/spl15. Our data suggest that miR529b is processed and functional in core eudicots and that this microRNA was recently lost in the evolutionary history of the ...
Descrição
Palavras-chave
Genetica vegetal, Botânica - Morfologia, Expressão gênica, Plantas - Efeito da auxina, Acido ribonucleico, Plants, Effect of auxin on
Como citar
MOREA, Edna Gicela Ortiz. Papel funcional de microRNAs na arquitetura vegetativa e radicular de plantas. 2013. 86 f. Dissertação (mestrado) - Universidade Estadual Paulista Júlio de Mesquita Filho, Instituto de Biociências de Botucatu, 2013.