Identificación de proteínas implicadas en la interacción arabidopsis-pseudomonas mediante tecnología "phage-display". caracterización funcional de aterf1 y erf1 en respuesta a estrés

[EN] Phage-display technology can be used to express and select for Arabidopsis proteins with functional microbe-binding domains. In this Thesis, two libraries for phage-mediated display of Arabidopsis proteins were constructed. A biopanning procedure using living cell of Pseudomonas sp. was used for selection of particular phage clones, such as T7-ATERF-1, which confirmed their microbe-binding capacity in competitive assays. DNA-microarray hybridization was used to high-throughput quantify clone enrichment during the selection. Significance analysis of microarray data produced upon hybridization of bio-panned libraries identified 472 genes as putative binders of bacterial molecules. GFP-ATERF-1 translocates from the nucleus to the cytoplasm upon infiltration with Pseudomonas components into the leaves of transgenic tobacco and Arabidopsis plants. A loss-of-function aterf-1 mutant is more sensitive to Pst than Col-0, which demonstrates that ATERF-1 is required for a proper immune response in vivo. The overexpression of ERF1 in Arabidopsis confers tolerance to drought. Specifically, under drought conditions ERF1 blocks the induction of the transcriptional drought-repressors DEAR5 and AtERF4 allowing the transcription of drought-responsive genes, and consequently an enhanced drought response. ERF1 expression is increased after drought stress and this expression is ET-dependent. Furthermore, ERF1 expression is decreased by ABA-treatment through an ET-independent pathway, suggesting ERF1 is a key node in the interaction between ABA and ET signalling pathways during abiotic stress. ERF1 overexpression prevents early seedling growth during salt and osmotic stresses and confers hypersensitivity to exogenous addition of ABA. ERF1 acts downstream of HAB2 in the ABA signalling pathway that regulates early seedling establishment and is able to antagonize HAB2 function. The overexpression of ERF1 promotes ABI5 protein accumulation, both in absence and presence of ABA, early in the post-germinative period. Our results suggest that transgenic 35S:ERF1 plants show delayed seedling establishment in response to abiotic stress or exogenous ABA, due to these higher ABI5 levels.

Author

• Rioja Llerena, Cristina

• Tesis y disertaciones académicas
• Universidad de Salamanca (España)
• Tesis Doctoral
• Academic dissertations
• Genética molecular de las plantas
• Fitopatología
• Fisiología vegetal

Identifier

hdl:10366/121214

OAI identifier oai:identifier

oai:gredos.usal.es:10366/121214