Data/hora: 29/05/2024 02:34:14

Biblioteca(s): | Embrapa Agrobiologia; Embrapa Agropecuária Oeste; Embrapa Hortaliças; Embrapa Meio-Norte.
Data corrente: | 25/08/2004
Data da última atualização: | 25/08/2004
Autoria: | CHALFUN JUNIOR, A.
Título: | Molecular analysis of plant architecture in Arabidopsis thaliana using activation tagging.
Ano de publicação: | 2004
Fonte/Imprenta: | 2004.
Páginas: | 144 p.
Idioma: | Inglês
Notas: | Thesis (Doctor)- Wageningen Universiteit, Wageningen, 2004.

Conteúdo:

Activation and suppression; getting insights in regulatory switches controlling plant development. Analysis of the SHP2 enhancer for the use of tissue specific activation tagging in Arabidopsis thaliana. Low frequency of T-DNA based activation tagging in Arabidopsis is correlated with methylation of CaMV35S enhancer sequences. Downwards siliquesi, a member of the lateral organ boundary family, controls petiole-blade boundary in Arabidopsis petals. Needlei, a Helix-Loop-Helix transcription factor involved in Arabidopsis carpel development. Overexpression of the Arabidopsis Twistedi gene affects plant architecture. 
Plant development is one of the most important aspects of plant's life cycle that has extensively been studied at the morphologiacal, genetic and molecular level. It is import for systematic and taxonomic classification, but also for applied agronomic reasons, because it affects the growth and cultivation leading to higher yield and quality of the product. The generation of genetc variants, like mutants may increase genetic pool and gives information about plant processes and their  genetic  control. Activation tagging is a new poewrful tool to generate and identify new mutants, which emerged as an alternative for gene function analysis. This thesis reports the study on the molecular control of plant architecture, using mutants generated by an activation tagging-based approach in the model plat Arabidopsis thaliana. In addition, it  also describes experiments that could explain why tha low frequencies of mutants were obtained by T-DNA based activation tagging. Based on this comparison, the transposon-based activation tagging strategy was chosen and a screen for flower and silique in a large Arabidopsis population yielded three gain-of-function mutants. These mutants were designated downwards siliques 1 (ds 1-D), needlel (ndl1-D) and twisted 1 (twt 1-D).in the ds 1-D mutant, internodes are shorter and the lateral organs such as flowers are bending downwards. Further molecular and genetic studies on this mutant evealed that DS 1 is important to control petiole-blade boundary in Arabidopsis petals. In the ndl 1-D  mutant, the normal formation of valve tissues is altered, resulting in a pin-like structure that replaces the two carpels of the wild type pistil. The results suggest that suggest that NDL 1 is involved in normail carpel development, in which auxin distribution plays an important role. In the third mutant, twt 1-D, the overexpression of TWT 1 led to twisting of all organs, which is most pronounced in siliques. This phenotype and the expression pattern of the gene suggest that TWT 1 is involve in prope vascular tissue development in Arabidopsis. These studies demonstrate the power of activation tagging and it gains valuable knowledge about the molecular networks that control plant development.

Palavras-Chave: | Ativação genética marcada; Ativação géntica marcada; Classificação botânica; Controle molecular; Cultivo; Desenvolvimento; T - DNA; T DNA.
Thesagro: | Arquitetura; Erva Daninha; Mutante; Planta; Produtividade; Qualidade; Taxonomia Vegetal.
Thesaurus Nal: | Arabidopsis thaliana.
Categoria do assunto: | --
Registro original: | Embrapa Agropecuária Oeste (CPAO)

Exemplares:

CPAO - (22401-1) - ADP - TS - -- - T 03/04 -  - 04.00052 - DIS
CNPAB - (32637-1) - ADD - TS - -- - 2005.00006 -  - 2005.00006 - DIS
CNPH - (28757-1) - ADD - TS - -- - T CHA 27/04 -  - 2004.27 - DIS
CPAMN - (26647-1) - ADD - TS - PP - T 26/04 -  - 2004.00026 - DIS