title: Independent and interactive effects of DOF affecting germination 1 (DAG1) and the Della proteins GA insensitive (GAI) and Repressor of ga1-3 (RGA) in embryo development and seed germination.
abstract: BACKGROUND
  The transcription factor DOF AFFECTING GERMINATION1 (DAG1) is a repressor of seed germination acting downstream of the master repressor PHYTOCROME INTERACTING FACTOR3-LIKE 5 (PIL5). Among others, PIL5 induces the expression of the genes encoding the two DELLA proteins GA INSENSITIVE 1 (GAI) and REPRESSOR OF ga1-3 (RGA).
  
  
  RESULTS
  Based on the properties of gai-t6 and rga28 mutant seeds, we show here that the absence of RGA severely increases dormancy, while lack of GAI only partially compensates RGA inactivation. In addition, the germination properties of the dag1rga28 double mutant are different from those of the dag1 and rga28 single mutants, suggesting that RGA and DAG1 act in independent branches of the PIL5-controlled germination pathway. Surprisingly, the dag1gai-t6 double mutant proved embryo-lethal, suggesting an unexpected involvement of (a possible complex between) DAG1 and GAI in embryo development.
  
  
  CONCLUSIONS
  Rather than overlapping functions as previously suggested, we show that RGA and GAI play distinct roles in seed germination, and that GAI interacts with DAG1 in embryo development.
authors: Alessandra
authors: A
authors: Boccaccini
authors: Silvia
authors: S
authors: Santopolo
authors: Davide
authors: D
authors: Capauto
authors: Riccardo
authors: R
authors: Lorrai
authors: Emanuele
authors: E
authors: Minutello
authors: Katia
authors: K
authors: Belcram
authors: Jean-Cristophe
authors: JC
authors: Palauqui
authors: Paolo
authors: P
authors: Costantino
authors: Paola
authors: P
authors: Vittorioso
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D047108:Embryonic Development; D004843:Epistasis, Genetic; D018525:Germination; D009154:Mutation; D010641:Phenotype; D012097:Repressor Proteins / Q000378:metabolism*; D012639:Seeds / Q000254:growth & development; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C407526:DAG1 protein, Arabidopsis; D004268:DNA-Binding Proteins; C109555:GAI protein, Arabidopsis; C508468:RGA protein, Arabidopsis; D012097:Repressor Proteins; D014157:Transcription Factors