INVESTIGADORES
GRAS Diana Ester
congresos y reuniones científicas
Título:
TGA1 and TGA4 transcription factors modulate nitrate responses in Arabidopsis thaliana roots
Autor/es:
ÁLVAREZ JM; RIVERAS E; GRAS DE; VIDAL EA; CONTRERAS-LOPEZ O; TAMAYO KP; GOMEZ MI; RUFFEL S; LEJAY L; JORDANA X; GUTIÉRREZ RG
Lugar:
Puerto Varas
Reunión:
Simposio; Second International Symposium on the Nitrogen Nutrition of Plants; 2013
Resumen:
Nitrogen (N) nutrient and metabolites regulate plant growth and development and act as potent signals to control gene expression in Arabidopsis. Using an integrative bioinformatics approach we identified TGA1 and TGA4 as putative regulatory factors that mediate N responses in Arabidopsis thaliana roots. We showed that both TGA1 and TGA4 mRNAs accumulate strongly after nitrate treatments in root organs. Phenotypic analysis of tga1 and tga4 double mutant plants indicated that TGA1 and TGA4 are necessary for both primary and lateral root growth in a nitrate dependent manner. Global gene expression analyses revealed that 97% of the genes with altered expression in the tga1/tga4 double mutants are regulated by nitrate treatments indicating these transcription factors have a specific role in nitrate responses in Arabidopsis roots. Among the nitrate-responsive genes that depend on TGA1/TGA4 for normal regulation of gene expression, we found the nitrate transporters NRT2.1 and NRT2.2. Specific binding of TGA1 to its cognate DNA sequence on the target gene promoters was confirmed by chromatin immunoprecipitation assays. These results identify TGA1 and TGA4 as important regulatory factors of the nitrate response in Arabidopsis roots.